Smart Power Grids

Resilience, scalability and safety of operations is critical for power grid. Ensuring that the system operates resiliently while handling the challenges of both component failures, environmental uncertainty and adversarial attacks is not easy. The challenge in this domain include data corruption, failure and misoperation of protection equipment, and the possibility of misclassification of a fault by the AI system. System integration and operation of the grid remains open challenges. Further, the emerging trend in this domain is networked microgrids that can island or be connected together to respond to adversities. However, dynamic formation of networked microgrids for heterogeneous components is not a solved problem. System integrators must often put together a microgrid from available components that communicate different information, at different rates, using different protocols. Due to variations in the microgrid architectures and their generation and load mix, each microgrid solution is customized and site-specific.

Publications in this area

H. M. Mustafa, M. Bariya, K. S. Sajan, A. Chhokra, A. Srivastava, A. Dubey, A. von Meier, and G. Biswas, RT-METER: A Real-Time, Multi-Layer Cyber–Power Testbed for Resiliency Analysis, in 9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2021.
```
@inproceedings{rtmeter2021,
  author = {Mustafa, Hussain M. and Bariya, Mohini and Sajan, K.S. and Chhokra, Ajay and Srivastava, Anurag and Dubey, Abhishek and von Meier, Alexandra and Biswas, Gautam},
  title = {RT-METER: A Real-Time, Multi-Layer Cyber–Power Testbed for Resiliency Analysis},
  booktitle = {9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek},
  year = {2021},
  category = {workshop},
  keywords = {power grid},
  project = {cps-reliability},
  tag = {platform,power}
}
```
In this work, we present a Real-Time, Multi-layer cybEr–power TestbEd for the Resiliency analysis (RT-METER) to support power grid operation and planning. Developed cyber-power testbed provides a mechanism for end-to-end validation of advanced tools for cyber-power grid monitoring, control, and planning. By integrating a host of features across three core layers—physical power system, communication network, and monitoring/ control center with advanced tools,—the testbed allows for the simulation of rich and varied cyber-power grid scenarios and the generating realistic sensor, system, and network data. Developing advanced tools to assist operators during complex and challenging scenarios is essential for the successful operation of the future grid. We detail a suite of algorithmic tools validated using the developed testbed for the realistic grid data.
A. Chhokra, C. Barreto, A. Dubey, G. Karsai, and X. Koutsoukos, Power-Attack: A comprehensive tool-chain for modeling and simulating attacks in power systems, in 9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2021.
```
@inproceedings{ajay2021powerattack,
  author = {Chhokra, Ajay and Barreto, Carlos and Dubey, Abhishek and Karsai, Gabor and Koutsoukos, Xenofon},
  title = {Power-Attack: A comprehensive tool-chain for modeling and simulating attacks in power systems},
  booktitle = {9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek},
  year = {2021},
  category = {workshop},
  keywords = {power grid},
  project = {cps-reliability},
  tag = {platform,power}
}
```
Due to the increased deployment of novel communication, control and protection functions, the grid has become vulnerable to a variety of attacks. Designing robust machine learning based attack detection and mitigation algorithms require large amounts of data that rely heavily on a representative environment, where different attacks can be simulated. This paper presents a comprehensive tool-chain for modeling and simulating attacks in power systems. The paper makes the following contributions, first, we present a probabilistic domain specific language to define multiple attack scenarios and simulation configuration parameters. Secondly, we extend the PyPower-dynamics simulator with protection system components to simulate cyber attacks in control and protection layers of power system. In the end, we demonstrate multiple attack scenarios with a case study based on IEEE 39 bus system.
S. Eisele, T. Eghtesad, K. Campanelli, P. Agrawal, A. Laszka, and A. Dubey, Safe and Private Forward-Trading Platform for Transactive Microgrids, ACM Trans. Cyber-Phys. Syst., vol. 5, no. 1, Jan. 2021.
```
@article{eisele2020Safe,
  author = {Eisele, Scott and Eghtesad, Taha and Campanelli, Keegan and Agrawal, Prakhar and Laszka, Aron and Dubey, Abhishek},
  title = {Safe and Private Forward-Trading Platform for Transactive Microgrids},
  year = {2021},
  issue_date = {January 2021},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  volume = {5},
  number = {1},
  tag = {decentralization, power},
  issn = {2378-962X},
  url = {https://doi.org/10.1145/3403711},
  doi = {10.1145/3403711},
  journal = {ACM Trans. Cyber-Phys. Syst.},
  month = jan,
  articleno = {8},
  numpages = {29},
  keywords = {privacy, cyber-physical system, decentralized application, smart contract, transactive energy, Smart grid, distributed ledger, blockchain}
}
```
Transactive microgrids have emerged as a transformative solution for the problems faced by distribution system operators due to an increase in the use of distributed energy resources and rapid growth in renewable energy generation. Transactive microgrids are tightly coupled cyber and physical systems, which require resilient and robust financial markets where transactions can be submitted and cleared, while ensuring that erroneous or malicious transactions cannot destabilize the grid. In this paper, we introduce TRANSAX, a novel decentralized platform for transactive microgrids. TRANSAX enables participants to trade in an energy futures market, which improves efficiency by finding feasible matches for energy trades, reducing the load on the distribution system operator. TRANSAX provides privacy to participants by anonymizing their trading activity using a distributed mixing service, while also enforcing constraints that limit trading activity based on safety requirements, such as keeping power flow below line capacity. We show that TRANSAX can satisfy the seemingly conflicting requirements of efficiency, safety, and privacy, and we demonstrate its performance using simulation results.
K. Sajan, M. Bariya, S. Basak, A. K. Srivastava, A. Dubey, A. von Meier, and G. Biswas, Realistic Synchrophasor Data Generation for Anomaly Detection and Event Classification, in 8th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2020.
```
@inproceedings{basak2020mscpes,
  author = {Sajan, Kaduvettykunnal and Bariya, Mohini and Basak, Sanchita and Srivastava, Anurag K. and Dubey, Abhishek and von Meier, Alexandra and Biswas, Gautam},
  title = {Realistic Synchrophasor Data Generation for Anomaly Detection and Event Classification},
  booktitle = {8th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek},
  year = {2020},
  category = {workshop},
  keywords = {transactive},
  project = {cps-reliability},
  tag = {platform,power}
}
```
The push to automate and digitize the electric grid has led to widespread installation of Phasor Measurement Units (PMUs) for improved real-time wide-area system monitoring and control. Nevertheless, transforming large volumes of highresolution PMU measurements into actionable insights remains challenging. A central challenge is creating flexible and scalable online anomaly detection in PMU data streams. PMU data can hold multiple types of anomalies arising in the physical system or the cyber system (measurements and communication networks). Increasing the grid situational awareness for noisy measurement data and Bad Data (BD) anomalies has become more and more significant. Number of machine learning, data analytics and physics based algorithms have been developed for anomaly detection, but need to be validated with realistic synchophasor data. Access to field data is very challenging due to confidentiality and security reasons. This paper presents a method for generating realistic synchrophasor data for the given synthetic network as well as event and bad data detection and classification algorithms. The developed algorithms include Bayesian and change-point techniques to identify anomalies, a statistical approach for event localization and multi-step clustering approach for event classification. Developed algorithms have been validated with satisfactory results for multiple examples of power system events including faults and load/generator/capacitor variations/switching for an IEEE test system. Set of synchrophasor data will be available publicly for other researchers.
G. Pettet, M. Ghosal, S. Mahserejian, S. Davis, S. Sridhar, A. Dubey, and M. Meyer, A Decision Support Framework for Grid-Aware Electric Bus Charge Scheduling, in 2020 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2020.
```
@inproceedings{pettetisgt2020,
  author = {Pettet, Geoffrey and Ghosal, Malini and Mahserejian, Shant and Davis, Sarah and Sridhar, Siddharth and Dubey, Abhishek and Meyer, Michael},
  title = {A Decision Support Framework for Grid-Aware Electric Bus Charge Scheduling},
  booktitle = {2020 IEEE Power \& Energy Society Innovative Smart Grid Technologies Conference (ISGT)},
  year = {2020},
  organization = {IEEE},
  tag = {ai4cps,power}
}
```
While there are many advantages to electric public transit vehicles, they also pose new challenges for fleet operators. One key challenge is defining a charge scheduling policy that minimizes operating costs and power grid disruptions while maintaining schedule adherence. An uncoordinated policy could result in buses running out of charge before completing their trip, while a grid agnostic policy might incur higher energy costs or cause an adverse impact on the grid’s distribution system. We present a grid aware decision-theoretic framework for electric bus charge scheduling that accounts for energy price and grid load. The framework co-simulates models for traffic (Simulation of Urban Mobility) and the electric grid (GridLAB-D), which are used by a decision-theoretic planner to evaluate charging decisions with regard to their long-term effect on grid reliability and cost. We evaluated the framework on a simulation of Richland, WA’s bus and grid network, and found that it could save over $100k per year on operating costs for the city compared to greedy methods.
S. Eisele, C. Barreto, A. Dubey, X. Koutsoukos, T. Eghtesad, A. Laszka, and A. Mavridou, Blockchains for Transactive Energy Systems: Opportunities, Challenges, and Approaches, IEEE Computer, 2020.
```
@article{eisele2020Blockchains,
  author = {Eisele, Scott and Barreto, Carlos and Dubey, Abhishek and Koutsoukos, Xenofon and Eghtesad, Taha and Laszka, Aron and Mavridou, Anastasia},
  title = {Blockchains for Transactive Energy Systems: Opportunities, Challenges, and Approaches},
  journal = {IEEE Computer},
  year = {2020},
  tag = {platform,decentralization,power}
}
```
The emergence of blockchains and smart contracts have renewed interest in electrical cyber-physical systems, especially in the area of transactive energy systems. However, despite recent advances, there remain significant challenges that impede the practical adoption of blockchains in transactive energy systems, which include implementing complex market mechanisms in smart contracts, ensuring safety of the power system, and protecting residential consumers’ privacy. To address these challenges, we present TRANSAX, a blockchain-based transactive energy system that provides an efficient, safe, and privacy-preserving market built on smart contracts. Implementation and deployment of TRANSAX in a verifiably correct and efficient way is based on VeriSolid, a framework for the correct-by-construction development of smart contracts, and RIAPS, a middleware for resilient distributed power systems
C. Barreto, T. Eghtesad, S. Eisele, A. Laszka, A. Dubey, and X. Koutsoukos, Cyber-Attacks and Mitigation in Blockchain Based Transactive Energy Systems, in 3rd IEEE International Conference on IndustrialCyber-Physical Systems (ICPS 2020), 2020.
```
@inproceedings{barretocyber2020,
  author = {Barreto, Carlos and Eghtesad, Taha and Eisele, Scott and Laszka, Aron and Dubey, Abhishek and Koutsoukos, Xenofon},
  title = {Cyber-Attacks and Mitigation in Blockchain Based Transactive Energy Systems},
  booktitle = {3rd IEEE International Conference on IndustrialCyber-Physical Systems (ICPS 2020)},
  year = {2020},
  category = {selectiveconference},
  keywords = {transactive},
  project = {cps-reliability},
  tag = {decentralization,power}
}
```
Power grids are undergoing major changes due to the rapid adoption of intermittent renewable energy resources and the increased availability of energy storage devices. These trends drive smart-grid operators to envision a future where peer-to-peer energy trading occurs within microgrids, leading to the development of Transactive Energy Systems. Blockchains have garnered significant interest from both academia and industry for their potential application in decentralized TES, in large part due to their high level of resilience. In this paper, we introduce a novel class of attacks against blockchain based TES, which target the gateways that connect market participants to the system. We introduce a general model of blockchain based TES and study multiple threat models and attack strategies. We also demonstrate the impact of these attacks using a testbed based on GridLAB-D and a private Ethereum network. Finally, we study how to mitigate these attack.
S. Hasan, A. Dubey, G. Karsai, and X. Koutsoukos, A game-theoretic approach for power systems defense against dynamic cyber-attacks, International Journal of Electrical Power & Energy Systems, vol. 115, 2020.
```
@article{Hasan2020,
  author = {Hasan, Saqib and Dubey, Abhishek and Karsai, Gabor and Koutsoukos, Xenofon},
  title = {A game-theoretic approach for power systems defense against dynamic cyber-attacks},
  journal = {International Journal of Electrical Power \& Energy Systems},
  year = {2020},
  volume = {115},
  issn = {0142-0615},
  doi = {https://doi.org/10.1016/j.ijepes.2019.105432},
  file = {:Hasan2020-A_Game_Theoretic_Approach_for_Power_Systems_Defense_against_Dynamic_Cyber_Attacks.pdf:PDF},
  keywords = {Cascading failures, Cyber-attack, Dynamic attack, Game theory, Resilience, Smart grid, Static attack, smartgrid, reliability},
  project = {cps-reliability},
  tag = {platform,power},
  url = {http://www.sciencedirect.com/science/article/pii/S0142061519302807}
}
```
Technological advancements in today’s electrical grids give rise to new vulnerabilities and increase the potential attack surface for cyber-attacks that can severely affect the resilience of the grid. Cyber-attacks are increasing both in number as well as sophistication and these attacks can be strategically organized in chronological order (dynamic attacks), where they can be instantiated at different time instants. The chronological order of attacks enables us to uncover those attack combinations that can cause severe system damage but this concept remained unexplored due to the lack of dynamic attack models. Motivated by the idea, we consider a game-theoretic approach to design a new attacker-defender model for power systems. Here, the attacker can strategically identify the chronological order in which the critical substations and their protection assemblies can be attacked in order to maximize the overall system damage. However, the defender can intelligently identify the critical substations to protect such that the system damage can be minimized. We apply the developed algorithms to the IEEE-39 and 57 bus systems with finite attacker/defender budgets. Our results show the effectiveness of these models in improving the system resilience under dynamic attacks.
H. Tu, S. Lukic, A. Dubey, and G. Karsai, An LSTM-Based Online Prediction Method for Building Electric Load During COVID-19, in Annual Conference of the PHM Society, 2020.
```
@inproceedings{haophm2020,
  author = {Tu, Hao and Lukic, Srdjan and Dubey, Abhishek and Karsai, Gabor},
  title = {An LSTM-Based Online Prediction Method for Building Electric Load During COVID-19},
  booktitle = {Annual Conference of the PHM Society},
  year = {2020},
  tag = {ai4cps,power}
}
```
Accurate prediction of electric load is critical to optimally controlling and operating buildings. It provides the opportunities to reduce building energy consumption and to implement advanced functionalities such as demand response in the context of smart grid. However, buildings are nonstationary and it is important to consider the underlying concept changes that will affect the load pattern. In this paper we present an online learning method for predicting building electric load during concept changes such as COVID-19. The proposed methods is based on online Long Short-Term Memory (LSTM) recurrent neural network. To speed up the learning process during concept changes and improve prediction accuracy, an ensemble of multiple models with different learning rates is used. The learning rates are updated in realtime to best adapt to the new concept while maintaining the learned information for the prediction.

A. Chhokra, S. Hasan, A. Dubey, and G. Karsai, A Binary Decision Diagram Based Cascade Prognostics Scheme For Power Systems, in 2020 American control conference, 2020.

@inproceedings{chokraACC2020,
  author = {Chhokra, Ajay and Hasan, Saqib and Dubey, Abhishek and Karsai, Gabor},
  title = {A Binary Decision Diagram Based Cascade Prognostics Scheme For Power Systems},
  booktitle = {2020 American control conference},
  year = {2020},
  organization = {IEEE},
  note = {accepted for publication},
  category = {selective conference},
  keywords = {smartgird},
  tag = {platform,power}
}

Y. Zhang, S. Eisele, A. Dubey, A. Laszka, and A. K. Srivastava, Cyber-Physical Simulation Platform for Security Assessment of Transactive Energy Systems, in 7th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek 2019, Montreal, QC, Canada, 2019, pp. 1–6.
```
@inproceedings{Zhang2019a,
  author = {Zhang, Yue and Eisele, Scott and Dubey, Abhishek and Laszka, Aron and Srivastava, Anurag K.},
  title = {Cyber-Physical Simulation Platform for Security Assessment of Transactive Energy Systems},
  booktitle = {7th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek 2019, Montreal, QC, Canada},
  year = {2019},
  pages = {1--6},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/cpsweek/ZhangEDLS19},
  category = {workshop},
  doi = {10.1109/MSCPES.2019.8738802},
  file = {:Zhang2019a-Cyber_Physical_Simulation_Platform_for_Security_Assessment_of_Transactive_Energy_Systems.pdf:PDF},
  keywords = {transactive},
  project = {transactive-energy,cps-reliability},
  tag = {platform,decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:56 +0200},
  url = {https://doi.org/10.1109/MSCPES.2019.8738802}
}
```
Transactive energy systems (TES) are emerging as a transformative solution for the problems that distribution system operators face due to an increase in the use of distributed energy resources and rapid growth in scalability of managing active distribution system (ADS). On the one hand, these changes pose a decentralized power system control problem, requiring strategic control to maintain reliability and resiliency for the community and for the utility. On the other hand, they require robust financial markets while allowing participation from diverse prosumers. To support the computing and flexibility requirements of TES while preserving privacy and security, distributed software platforms are required. In this paper, we enable the study and analysis of security concerns by developing Transactive Energy Security Simulation Testbed (TESST), a TES testbed for simulating various cyber attacks. In this work, the testbed is used for TES simulation with centralized clearing market, highlighting weaknesses in a centralized system. Additionally, we present a blockchain enabled decentralized market solution supported by distributed computing for TES, which on one hand can alleviate some of the problems that we identify, but on the other hand, may introduce newer issues. Future study of these differing paradigms is necessary and will continue as we develop our security simulation testbed.
A. Dubey, G. Karsai, P. Völgyesi, M. Metelko, I. Madari, H. Tu, Y. Du, and S. Lukic, Device Access Abstractions for Resilient Information Architecture Platform for Smart Grid, Embedded Systems Letters, vol. 11, no. 2, pp. 34–37, 2019.
```
@article{Dubey2019,
  author = {Dubey, Abhishek and Karsai, Gabor and V{\"{o}}lgyesi, P{\'{e}}ter and Metelko, Mary and Madari, Istv{\'{a}}n and Tu, Hao and Du, Yuhua and Lukic, Srdjan},
  title = {Device Access Abstractions for Resilient Information Architecture Platform for Smart Grid},
  journal = {Embedded Systems Letters},
  year = {2019},
  volume = {11},
  number = {2},
  pages = {34--37},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/esl/DubeyKVMMTDL19},
  doi = {10.1109/LES.2018.2845854},
  file = {:Dubey2019-Device_Access_Abstractions_for_Resilient_Information_Architecture_Platform_for_Smart_Grid.pdf:PDF},
  keywords = {middleware, smartgrid},
  project = {cps-middleware},
  tag = {platform,power},
  timestamp = {Fri, 05 Jul 2019 01:00:00 +0200},
  url = {https://doi.org/10.1109/LES.2018.2845854}
}
```
This letter presents an overview of design mechanisms to abstract device access protocols in the resilient information architecture platform for smart grid, a middleware for developing distributed smart grid applications. These mechanisms are required to decouple the application functionality from the specifics of the device mechanisms built by the device vendors.
S. Eisele, P. Ghosh, K. Campanelli, A. Dubey, and G. Karsai, Demo: Transactive Energy Application with RIAPS, in IEEE 22nd International Symposium on Real-Time Distributed Computing, ISORC 2019, Valencia, Spain, May 7-9, 2019, 2019, pp. 85–86.
```
@inproceedings{Eisele2019,
  author = {Eisele, Scott and Ghosh, Purboday and Campanelli, Keegan and Dubey, Abhishek and Karsai, Gabor},
  title = {Demo: Transactive Energy Application with {RIAPS}},
  booktitle = {{IEEE} 22nd International Symposium on Real-Time Distributed Computing, {ISORC} 2019, Valencia, Spain, May 7-9, 2019},
  year = {2019},
  pages = {85--86},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/isorc/EiseleGCDK19},
  category = {poster},
  doi = {10.1109/ISORC.2019.00024},
  file = {:Eisele2019-Demo_Transactive_Energy_Application_with_RIAPS.pdf:PDF},
  keywords = {transactive},
  project = {transactive-energy},
  tag = {decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:53 +0200},
  url = {https://doi.org/10.1109/ISORC.2019.00024}
}
```
The modern electric grid is a complex, decentralized cyber-physical system requiring higher-level control techniques to balance the demand and supply of energy to optimize the overall energy usage. The concept of Transactive Energy utilizes distributed system principle to address this challenge. In this demonstration we show the usage of the distributed application management platform RIAPS in the implementation of one such Transactive Energy approach to control elements of a power system, which runs as a a simulation using the Gridlab-d simulation solver.
P. Ghosh, S. Eisele, A. Dubey, M. Metelko, I. Madari, P. Völgyesi, and G. Karsai, On the Design of Fault-Tolerance in a Decentralized Software Platform for Power Systems, in IEEE 22nd International Symposium on Real-Time Distributed Computing, ISORC 2019, Valencia, Spain, 2019, pp. 52–60.
```
@inproceedings{Ghosh2019,
  author = {Ghosh, Purboday and Eisele, Scott and Dubey, Abhishek and Metelko, Mary and Madari, Istv{\'{a}}n and V{\"{o}}lgyesi, P{\'{e}}ter and Karsai, Gabor},
  title = {On the Design of Fault-Tolerance in a Decentralized Software Platform for Power Systems},
  booktitle = {{IEEE} 22nd International Symposium on Real-Time Distributed Computing, {ISORC} 2019, Valencia, Spain},
  year = {2019},
  pages = {52--60},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/isorc/GhoshEDMMVK19},
  category = {selectiveconference},
  doi = {10.1109/ISORC.2019.00018},
  file = {:Ghosh2019-On_the_Design_of_Fault-Tolerance_in_a_Decentralized_Software_Platform_for_Power_Systems.pdf:PDF},
  keywords = {middleware},
  project = {cps-middleware,cps-reliability},
  tag = {platform,decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:53 +0200},
  url = {https://doi.org/10.1109/ISORC.2019.00018}
}
```
The vision of the ‘Smart Grid’ assumes a distributed real-time embedded system that implements various monitoring and control functions. As the reliability of the power grid is critical to modern society, the software supporting the grid must support fault tolerance and resilience in the resulting cyber-physical system. This paper describes the fault-tolerance features of a software framework called Resilient Information Architecture Platform for Smart Grid (RIAPS). The framework supports various mechanisms for fault detection and mitigation and works in concert with the applications that implement the grid-specific functions. The paper discusses the design philosophy for and the implementation of the fault tolerance features and presents an application example to show how it can be used to build highly resilient systems.
A. Laszka, A. Mavridou, S. Eisele, E. Statchtiari, and A. Dubey, VeriSolid for TRANSAX: Correct-by-Design Ethereum Smart Contracts for Energy Trading, in First International Summer School on Security and Privacy for Blockchains and Distributed Ledger Technologies, BDLT 2019, Vienna, Austria, 2019.
```
@inproceedings{LaszkaVerisolid2019,
  author = {Laszka, Aron and Mavridou, Anastasia and Eisele, Scott and Statchtiari, Emmanouela and Dubey, Abhishek},
  title = {VeriSolid for TRANSAX: Correct-by-Design Ethereum Smart Contracts for Energy Trading},
  booktitle = {First International Summer School on Security and Privacy for Blockchains and Distributed Ledger Technologies, BDLT 2019, Vienna, Austria},
  year = {2019},
  month = sep,
  category = {workshop},
  file = {:LaszkaVerisolid2019Poster.pdf:PDF},
  keywords = {blockchain, transactive},
  project = {cps-blockchains,transactive-energy},
  tag = {platform,decentralization,power}
}
```
The adoption of blockchain based platforms is rising rapidly. Their popularity is explained by their ability to maintain a distributed public ledger, providing reliability, integrity, and auditability with- out a trusted entity. Recent platforms, e.g., Ethereum, also act as distributed computing platforms and enable the creation of smart contracts, i.e., software code that runs on the platform and automatically executes and enforces the terms of a contract. Since smart contracts can perform any computation, they allow the develop- ment of decentralized applications, whose execution is safeguarded by the security properties of the underlying platform. Due to their unique advantages, blockchain based platforms are envisioned to have a wide range of applications, ranging from financial to the Internet-of-Things. However, the trustworthiness of the platform guarantees only that a smart contract is executed correctly, not that the code of the contract is correct. In fact, a large number of contracts deployed in practice suffer from software vulnerabilities, which are often introduced due to the semantic gap between the assumptions that contract writers make about the underlying execution semantics and the actual semantics of smart contracts. A recent automated analysis of 19,336 smart contracts deployed in practice found that 8,333 of them suffered from at least one security issue. Although this study was based on smart contracts deployed on the public Ethereum blockchain, the analyzed security issues were largely plat- form agnostic. Security vulnerabilities in smart contracts present a serious issue for two main reasons. Firstly, smart-contract bugs cannot be patched. By design, once a contract is deployed, its func- tionality cannot be altered even by its creator. Secondly, once a faulty or malicious transaction is recorded, it cannot be removed from the blockchain (“code is law” principle). The only way to roll back a transaction is by performing a hard fork of the blockchain, which requires consensus among the stakeholders and undermines the trustworthiness of the platform. In light of this, it is crucial to ensure that a smart contract is se- cure before deploying it and trusting it with significant amounts of cryptocurrency. To this end, we present the VeriSolid framework for the formal verification and generation of contracts that are specified using a transition-system based model with rigorous operational semantics. VeriSolid provides an end-to-end design framework, which combined with a Solidity code generator, allows the correct- by-design development of Ethereum smart contracts. To the best of our knowledge, VeriSolid is the first framework to promote a model- based, correctness-by-design approach for blockchain-based smart contracts. Properties established at any step of the VeriSolid design flow are preserved in the resulting smart contracts, guaranteeing their correctness. VeriSolid fully automates the process of verifica- tion and code generation, while enhancing usability by providing easy-to-use graphical editors for the specification of transition sys- tems and natural-like language templates for the specification of formal properties. By performing verification early at design time, VeriSolid provides a cost-effective approach since fixing bugs later in the development process can be very expensive. Our verification approach can detect typical vulnerabilities, but it may also detect any violation of required properties. Since our tool applies verifi- cation at a high-level, it can provide meaningful feedback to the developer when a property is not satisfied, which would be much harder to do at bytecode level. We present the application of VeriSolid on smart contracts used in Smart Energy Systems such as transactive energy platforms. In particular, we used VeriSolid to design and generate the smart contract that serves as the core of the TRANSAX blockchain-based platform for trading energy futures. The designed smart contract allows energy producers and consumers to post offers for selling and buying energy. Since optimally matching selling offers with buying offers can be very expensive computationally, the contract relies on external solvers to compute and submit solutions to the matching problem, which are then checked by the contract. Using VeriSolid, we defined a set of safety properties and we were able to detect bugs after performing analysis with the NuSMV model checker.
H. Tu, Y. Du, H. Yu, A. Dubey, S. Lukic, and G. Karsai, Resilient Information Architecture Platform for the Smart Grid (RIAPS): A Novel Open-Source Platform for Microgrid Control, IEEE Transactions on Industrial Electronics, pp. 1–1, 2019.
```
@article{Tu2019,
  author = {{Tu}, H. and {Du}, Y. and {Yu}, H. and Dubey, Abhishek and {Lukic}, S. and {Karsai}, G.},
  title = {Resilient Information Architecture Platform for the Smart Grid (RIAPS): A Novel Open-Source Platform for Microgrid Control},
  journal = {IEEE Transactions on Industrial Electronics},
  year = {2019},
  pages = {1-1},
  issn = {1557-9948},
  doi = {10.1109/TIE.2019.2952803},
  file = {:Tu2019-Resilient_Information_Architecture_Platform_for_the_Smart_Grid(RIAPS)_A_Novel_Open-Source_Platform_for_Microgrid_Control.pdf:PDF},
  keywords = {smartgrid},
  project = {cps-middleware,cps-reliability,smart-energy},
  tag = {decentralization,power}
}
```
Microgrids are seen as an effective way to achieve reliable, resilient, and efficient operation of the power distribution system. Core functions of the microgrid control system are defined by the IEEE standard 2030.7; however, the algorithms that realize these functions are not standardized, and are a topic of research. Furthermore, the corresponding controller hardware, operating system, and communication system to implement these functions vary significantly from one implementation to the next. In this paper, we introduce an open-source platform, Resilient Information Architecture Platform for the Smart Grid (RIAPS), ideally suited for implementing and deploying distributed microgrid control algorithms. RIAPS provides a design-time tool suite for development and deployment of distributed microgrid control algorithms. With support from a number of run-time platform services, developed algorithms can be easily implemented and deployed into real microgrids. To demonstrate the unique features of RIAPS, we propose and implement a distributed microgrid secondary control algorithm capable of synchronized and proportional compensation of voltage unbalance using distributed generators. Test results show the effectiveness of the proposed control and the salient features of the RIAPS platform.
A. Laszka, S. Eisele, A. Dubey, G. Karsai, and K. Kvaternik, TRANSAX: A Blockchain-Based Decentralized Forward-Trading Energy Exchanged for Transactive Microgrids, in 24th IEEE International Conference on Parallel and Distributed Systems, ICPADS 2018, Singapore, December 11-13, 2018, 2018, pp. 918–927.
```
@inproceedings{Laszka2018,
  author = {Laszka, Aron and Eisele, Scott and Dubey, Abhishek and Karsai, Gabor and Kvaternik, Karla},
  title = {{TRANSAX:} {A} Blockchain-Based Decentralized Forward-Trading Energy Exchanged for Transactive Microgrids},
  booktitle = {24th {IEEE} International Conference on Parallel and Distributed Systems, {ICPADS} 2018, Singapore, December 11-13, 2018},
  year = {2018},
  pages = {918--927},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/icpads/LaszkaEDKK18},
  category = {selectiveconference},
  doi = {10.1109/PADSW.2018.8645001},
  file = {:Laszka2018-TRANSAX_A_Blockchain-Based_Decentralized_Forward-Trading_Energy_Exchanged_for_Transactive_Microgrids.pdf:PDF},
  keywords = {transactive, blockchain},
  project = {transactive-energy,cps-blockchains},
  tag = {decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:56 +0200},
  url = {https://doi.org/10.1109/PADSW.2018.8645001}
}
```
Power grids are undergoing major changes due to rapid growth in renewable energy and improvements in battery technology. Prompted by the increasing complexity of power systems, decentralized IoT solutions are emerging, which arrange local communities into transactive microgrids. The core functionality of these solutions is to provide mechanisms for matching producers with consumers while ensuring system safety. However, there are multiple challenges that these solutions still face: privacy, trust, and resilience. The privacy challenge arises because the time series of production and consumption data for each participant is sensitive and may be used to infer personal information. Trust is an issue because a producer or consumer can renege on the promised energy transfer. Providing resilience is challenging due to the possibility of failures in the infrastructure that is required to support these market based solutions. In this paper, we develop a rigorous solution for transactive microgrids that addresses all three challenges by providing an innovative combination of MILP solvers, smart contracts, and publish-subscribe middleware within a framework of a novel distributed application platform, called Resilient Information Architecture Platform for Smart Grid. Towards this purpose, we describe the key architectural concepts, including fault tolerance, and show the trade-off between market efficiency and resource requirements.
S. Hasan, A. Ghafouri, A. Dubey, G. Karsai, and X. D. Koutsoukos, Vulnerability analysis of power systems based on cyber-attack and defense models, in 2018 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference, ISGT 2018, Washington, DC, USA, February 19-22, 2018, 2018, pp. 1–5.
```
@inproceedings{Hasan2018,
  author = {Hasan, Saqib and Ghafouri, Amin and Dubey, Abhishek and Karsai, Gabor and Koutsoukos, Xenofon D.},
  title = {Vulnerability analysis of power systems based on cyber-attack and defense models},
  booktitle = {2018 {IEEE} Power {\&} Energy Society Innovative Smart Grid Technologies Conference, {ISGT} 2018, Washington, DC, USA, February 19-22, 2018},
  year = {2018},
  pages = {1--5},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/isgt/HasanGDKK18},
  category = {selectiveconference},
  doi = {10.1109/ISGT.2018.8403337},
  file = {:Hasan2018-Vulnerability_analysis_of_power_systems_based_on_cyber-attack_and_defense_models.pdf:PDF},
  keywords = {smartgrid},
  project = {cps-reliability},
  tag = {platform,power},
  timestamp = {Wed, 16 Oct 2019 14:14:57 +0200},
  url = {https://doi.org/10.1109/ISGT.2018.8403337}
}
```
Reliable operation of power systems is a primary challenge for the system operators. With the advancement in technology and grid automation, power systems are becoming more vulnerable to cyber-attacks. The main goal of adversaries is to take advantage of these vulnerabilities and destabilize the system. This paper describes a game-theoretic approach to attacker / defender modeling in power systems. In our models, the attacker can strategically identify the subset of substations that maximize damage when compromised. However, the defender can identify the critical subset of substations to protect in order to minimize the damage when an attacker launches a cyber-attack. The algorithms for these models are applied to the standard IEEE-14, 39, and 57 bus examples to identify the critical set of substations given an attacker and a defender budget.
S. Eisele, A. Laszka, A. Mavridou, and A. Dubey, SolidWorx: A Resilient and Trustworthy Transactive Platform for Smart and Connected Communities, in IEEE International Conference on Internet of Things and Blockchains, 2018, pp. 1263–1272.
```
@inproceedings{Eisele2018,
  author = {Eisele, Scott and Laszka, Aron and Mavridou, Anastasia and Dubey, Abhishek},
  title = {SolidWorx: {A} Resilient and Trustworthy Transactive Platform for Smart and Connected Communities},
  booktitle = {{IEEE} International Conference on Internet of Things and Blockchains},
  year = {2018},
  pages = {1263--1272},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/ithings/EiseleLMD18},
  category = {selectiveconference},
  doi = {10.1109/Cybermatics\_2018.2018.00221},
  file = {:Eisele2018-SolidWorx_A_Resilient_and_Trustworthy_Transactive_Platform_for_Smart_and_Connected_Communities.pdf:PDF},
  keywords = {blockchain, transactive},
  project = {cps-blockchains,transactive-energy},
  tag = {decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:56 +0200},
  url = {https://doi.org/10.1109/Cybermatics\_2018.2018.00221}
}
```
Internet of Things and data sciences are fueling the development of innovative solutions for various applications in Smart and Connected Communities (SCC). These applications provide participants with the capability to exchange not only data but also resources, which raises the concerns of integrity, trust, and above all the need for fair and optimal solutions to the problem of resource allocation. This exchange of information and resources leads to a problem where the stakeholders of the system may have limited trust in each other. Thus, collaboratively reaching consensus on when, how, and who should access certain resources becomes problematic. This paper presents SolidWorx, a blockchain-based platform that provides key mechanisms required for arbitrating resource consumption across different SCC applications in a domain-agnostic manner. For example, it introduces and implements a hybrid-solver pattern, where complex optimization computation is handled off-blockchain while solution validation is performed by a smart contract. To ensure correctness, the smart contract of SolidWorx is generated and verified using a model-based approach.
H. Tu, Y. Du, H. Yu, S. Lukic, M. Metelko, P. Volgyesi, A. Dubey, and G. Karsai, A Hardware-in-the-Loop Real-Time Testbed for Microgrid Hierarchical Control, in 2018 IEEE Energy Conversion Congress and Exposition (ECCE), 2018, pp. 2053–2059.
```
@inproceedings{Tu2018,
  author = {{Tu}, H. and {Du}, Y. and {Yu}, H. and {Lukic}, S. and {Metelko}, M. and {Volgyesi}, P. and Dubey, Abhishek and {Karsai}, G.},
  title = {A Hardware-in-the-Loop Real-Time Testbed for Microgrid Hierarchical Control},
  booktitle = {2018 IEEE Energy Conversion Congress and Exposition (ECCE)},
  year = {2018},
  pages = {2053-2059},
  month = sep,
  category = {conference},
  doi = {10.1109/ECCE.2018.8557737},
  file = {:Tu2018-A_Hardware-in-the-Loop_Real-Time_Testbed_for_Microgrid_Hierarchical_Control.pdf:PDF},
  issn = {2329-3721},
  keywords = {smartgrid},
  project = {cps-middleware,smart-energy},
  tag = {platform,power}
}
```
To maintain a stable, flexible and economic operation of a microgrid, hierarchical control architecture consisting of primary, secondary and tertiary control is proposed. However, the differences in dynamics of microgrid, bandwidths of control levels and speed of communication channels make it difficult to comprehensively validate the performance of the hierarchical control schemes. In this paper we propose a hardware-in-the-loop real-time testbed for microgrid hierarchical control. The proposed testbed can be used to validate control performance under different microgrid operating modes (grid-tied or islanded), different primary control schemes (current or voltage mode) and different secondary control approaches (centralized or distributed). The integration of industry-grade hardware that runs primary and secondary control into the testbed allows for complete emulation of microgrid operation, and facilitates the study of the effects of measurement noise, sampling and communication delays.
Y. Du, H. Tu, S. Lukic, A. Dubey, and G. Karsai, Distributed Microgrid Synchronization Strategy Using a Novel Information Architecture Platform, in 2018 IEEE Energy Conversion Congress and Exposition (ECCE), 2018, pp. 2060–2066.
```
@inproceedings{Du2018,
  author = {{Du}, Y. and {Tu}, H. and {Lukic}, S. and Dubey, Abhishek and {Karsai}, G.},
  title = {Distributed Microgrid Synchronization Strategy Using a Novel Information Architecture Platform},
  booktitle = {2018 IEEE Energy Conversion Congress and Exposition (ECCE)},
  year = {2018},
  pages = {2060-2066},
  month = sep,
  category = {conference},
  doi = {10.1109/ECCE.2018.8557695},
  file = {:Du2018-Distributed_Microgrid_Synchronization_Strategy_Using_a_Novel_Information_Architecture_Platform.pdf:PDF},
  issn = {2329-3721},
  keywords = {smartgrid},
  project = {cps-middleware,cps-reliability,smart-energy},
  tag = {power}
}
```
To seamlessly reconnect an islanded microgrid to the main grid, voltage phasors on both sides of the point of common coupling need to be synchronized before the main relay closes. In this paper, a distributed control strategy is proposed for microgrid synchronization operation. The proposed controller design utilizes pinning-based consensus algorithm to avoid system single point of failure. It is able to actively track the main grid frequency, provide a good coordination between frequency and phase regulation and ensure all distributed generations in the system proportionally share the load. Implementation of such distributed algorithm in practice is difficult because it requires mitigation of both distributed computing and power system engineering challenges. In this paper, a novel software platform called RIAPS platform is presented that helps implementing the proposed distributed synchronization strategy in practical hardware controllers. The performance of the controllers are validated using a real-time controller hardware-in-the-loop microgrid testbed.
H. Tu, Y. Du, H. Yu, S. Lukic, P. Volgyesi, M. Metelko, A. Dubey, and G. Karsai, An Adaptive Interleaving Algorithm for Multi-Converter Systems, in 2018 9th IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG), 2018, pp. 1–7.
```
@inproceedings{Tu2018a,
  author = {{Tu}, H. and {Du}, Y. and {Yu}, H. and {Lukic}, S. and {Volgyesi}, P. and {Metelko}, M. and Dubey, Abhishek and {Karsai}, G.},
  title = {An Adaptive Interleaving Algorithm for Multi-Converter Systems},
  booktitle = {2018 9th IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)},
  year = {2018},
  pages = {1-7},
  month = jun,
  category = {conference},
  doi = {10.1109/PEDG.2018.8447801},
  file = {:Tu2018a-An_Adaptive_Interleaving_Algorithm_for_Multi-Converter_Systems.pdf:PDF},
  issn = {2329-5767},
  keywords = {smartgrid},
  project = {cps-middleware,cps-reliability,smart-energy},
  tag = {power}
}
```
To integrate DC distributed generation (DG) with micro-source into the existing AC grid, a DC distribution bus can be used to couple on-site photovoltaics (PV), battery energy storage systems (BESS), and DC loads. If the converters connected to the DC bus are interleaved, the DC bus capacitor size could be minimized. In this paper, we propose an interleaving algorithm for multi-converter systems to minimize the current harmonics at switching frequency on the DC bus. The proposed algorithm is implemented using Resilient Information Architecture Platform for Smart Grid (RIAPS) platform. Hardware-in-the-Loop (HIL) simulation results based on Opal- RT are presented to validate its performance. The influence of synchronization frequency on the proposed algorithm are also considered.
Y. Du, H. Tu, S. Lukic, D. Lubkeman, A. Dubey, and G. Karsai, Development of a Controller Hardware-in-the-Loop Platform for Microgrid Distributed Control Applications, in 2018 IEEE Electronic Power Grid (eGrid), 2018, pp. 1–6.
```
@inproceedings{DuTu2018,
  author = {{Du}, Y. and {Tu}, H. and {Lukic}, S. and {Lubkeman}, D. and Dubey, Abhishek and {Karsai}, G.},
  title = {Development of a Controller Hardware-in-the-Loop Platform for Microgrid Distributed Control Applications},
  booktitle = {2018 IEEE Electronic Power Grid (eGrid)},
  year = {2018},
  pages = {1-6},
  month = nov,
  category = {selectiveconference},
  doi = {10.1109/eGRID.2018.8598696},
  file = {:DuTu2018-Development_of_a_Controller_Hardware-in-the-Loop_Platform_for_Microgrid_Distributed_Control_Applications.pdf:PDF},
  issn = {null},
  keywords = {smartgrid},
  tag = {power}
}
```
Microgrids (MGs) are ideally suited for distributed control solutions. However, implementation and validation of the developed distributed control algorithms are quite challenging. In this paper we propose a Controller Hardware-in-the-Loop (CHIL) platform for MG distributed control applications that satisfy the requirements of IEEE Std. 2030.7 for MG control systems. We describe two main features of the proposed platform: 1) a software platform that enables the implementation of control algorithms that have been developed analytically and 2) a real-time MG testbed that replicates practical MG operation environment by using real-time communication network and grid solutions. Implementation and validation of a distributed MG synchronization operation control strategy are used to demonstrate the performance of the proposed CHIL platform.
A. Chhokra, A. Dubey, N. Mahadevan, S. Hasan, and G. Karsai, Diagnosis in Cyber-Physical Systems with Fault Protection Assemblies, in Diagnosability, Security and Safety of Hybrid Dynamic and Cyber-Physical Systems, M. Sayed-Mouchaweh, Ed. Cham: Springer International Publishing, 2018, pp. 201–225.
```
@inbook{Chhokra2018,
  chapter = {Chapter 8},
  pages = {201--225},
  title = {Diagnosis in Cyber-Physical Systems with Fault Protection Assemblies},
  publisher = {Springer International Publishing},
  year = {2018},
  author = {Chhokra, Ajay and Dubey, Abhishek and Mahadevan, Nagabhushan and Hasan, Saqib and Karsai, Gabor},
  editor = {Sayed-Mouchaweh, Moamar},
  address = {Cham},
  isbn = {978-3-319-74962-4},
  booktitle = {Diagnosability, Security and Safety of Hybrid Dynamic and Cyber-Physical Systems},
  doi = {10.1007/978-3-319-74962-4_8},
  file = {:Chhokra2018-Diagnosis_In_Cyber-Physical_Systems_with_Fault_Protection_Assemblies.pdf:PDF},
  keywords = {reliability, smartgrid},
  tag = {platform,power},
  url = {https://doi.org/10.1007/978-3-319-74962-4_8}
}
```
Fault Protection Assemblies are used in cyber-physical systems for automated fault-isolation. These devices alter the mode of the system using locally available information in order to stop fault propagation. For example, in electrical networks relays and breakers isolate faults in order to arrest failure propagation and protect the healthy parts of the system. However, these assemblies themselves can have faults, which may inadvertently induce secondary failures. Often these secondary failures lead to cascade effects, which then lead to total system collapse. This behavior is often seen in electrical transmission systems where failures of relays and breakers may cause overloading and the disconnection of parts of an otherwise healthy system. In the past, we had developed a consistency based diagnosis approach for physical systems based on the temporal failure propagation graph. We now describe an extension that uses the concept of timed discrete event observers in combination with the timed failure propagation graphs to extend the hypothesis to include the possibility of failures in the fault protection units. Using a simulated power system case study, we show that the combined approach is able to diagnose faults in both the plant and the protection devices.
A. Chhokra, A. Dubey, N. Mahadevan, G. Karsai, D. Balasubramanian, and S. Hasan, Hierarchical Reasoning about Faults in Cyber-Physical Energy Systems using Temporal Causal Diagrams, International Journal of Prognostics and Health Management, vol. 9, no. 1, Feb. 2018.
```
@article{Chhokra2018a,
  author = {Chhokra, Ajay and Dubey, Abhishek and Mahadevan, Nagabhushan and Karsai, Gabor and Balasubramanian, Daniel and Hasan, Saqib},
  title = {Hierarchical Reasoning about Faults in Cyber-Physical Energy Systems using Temporal Causal Diagrams},
  journal = {International Journal of Prognostics and Health Management},
  year = {2018},
  volume = {9},
  number = {1},
  month = feb,
  attachments = {https://www.isis.vanderbilt.edu/sites/default/files/ijphm_18_001_0.pdf},
  file = {:Chhokra2018a-Hierarchical_Reasoning_about_Faults_in_Cyber-Physical_Energy_Systems_using_Temporal_Causal_Diagrams.pdf:PDF},
  keywords = {reliability, smartgrid},
  tag = {platform,power},
  type = {Journal Article},
  url = {https://www.phmsociety.org/node/2290}
}
```
The resiliency and reliability of critical cyber physical systems like electrical power grids are of paramount importance. These systems are often equipped with specialized protection devices to detect anomalies and isolate faults in order to arrest failure propagation and protect the healthy parts of the system. However, due to the limited situational awareness and hidden failures the protection devices themselves, through their operation (or mis-operation) may cause overloading and the disconnection of parts of an otherwise healthy system. This can result in cascading failures that lead to a blackout. Diagnosis of failures in such systems is extremely challenging because of the need to account for faults in both the physical systems as well as the protection devices, and the failure-effect propagation across the system. Our approach for diagnosing such cyber-physical systems is based on the concept of Temporal Causal Diagrams (TCD-s) that capture the timed discrete models of protection devices and their interactions with a system failure propagation graph. In this paper we present a refinement of the TCD language with a layer of independent local observers that aid in diagnosis. We describe a hierarchical two-tier failure diagnosis approach and showcase the results for 4 different scenarios involving both cyber and physical faults in a standard Western System Coordinating Council (WSCC) 9 bus system.
A. Chhokra, S. Hasan, A. Dubey, N. Mahadevan, and G. Karsai, Diagnostics and prognostics using temporal causal models for cyber physical energy systems, in Proceedings of the 8th International Conference on Cyber-Physical Systems, ICCPS 2017, Pittsburgh, Pennsylvania, USA, April 18-20, 2017, 2017, p. 87.
```
@inproceedings{Chhokra2017a,
  author = {Chhokra, Ajay and Hasan, Saqib and Dubey, Abhishek and Mahadevan, Nagabhushan and Karsai, Gabor},
  title = {Diagnostics and prognostics using temporal causal models for cyber physical energy systems},
  booktitle = {Proceedings of the 8th International Conference on Cyber-Physical Systems, {ICCPS} 2017, Pittsburgh, Pennsylvania, USA, April 18-20, 2017},
  year = {2017},
  tag = {platform,power},
  pages = {87},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/iccps/ChhokraHDMK17},
  category = {poster},
  doi = {10.1145/3055004.3064843},
  file = {:Chhokra2017a-Diagnostics_and_prognostics_using_temporal_causal_models_for_cyber_physical_energy_systems.pdf:PDF},
  keywords = {reliability, smartgrid},
  project = {cps-reliability},
  timestamp = {Wed, 16 Oct 2019 14:14:57 +0200},
  url = {https://doi.org/10.1145/3055004.3064843}
}
```
Reliable operation of cyber-physical systems such as power transmission and distribution systems is crtiical for the seamless functioning of a vibrant economy. These systems consist of tightly coupled physical (energy sources, transmission and distribution lines, and loads) and computational components (protection devices, energy management systems, etc.). The protection devices such as distance relays help in preventing failure propagation by isolating faulty physical components. However, these devices rely on hard thresholds and local information, often ignoring system-level effects introduced by the distributed control algorithms. This leads to scenarios wherein a local mitigation in a subsytem could trigger a larger fault cascade, possibly resulting in a blackout.Efficient models and tools that curtail such systematic failures by performing fault diagnosis and prognosis are therefore necessary.
S. Eisele, A. Dubey, G. Karsai, and S. Lukic, Transactive energy demo with RIAPS platform, in Proceedings of the 8th International Conference on Cyber-Physical Systems, ICCPS 2017, Pittsburgh, Pennsylvania, USA, April 18-20, 2017, 2017, p. 91.
```
@inproceedings{Eisele2017a,
  author = {Eisele, Scott and Dubey, Abhishek and Karsai, Gabor and Lukic, Srdjan},
  title = {Transactive energy demo with {RIAPS} platform},
  booktitle = {Proceedings of the 8th International Conference on Cyber-Physical Systems, {ICCPS} 2017, Pittsburgh, Pennsylvania, USA, April 18-20, 2017},
  year = {2017},
  pages = {91},
  tag = {decentralization,power},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/iccps/EiseleDKL17},
  category = {poster},
  doi = {10.1145/3055004.3064845},
  file = {:Eisele2017a-Transactive_energy_demo_with_RIAPS_platform.pdf:PDF},
  keywords = {transactive},
  project = {cps-reliability,cps-middleware,transactive-energy},
  timestamp = {Wed, 16 Oct 2019 14:14:57 +0200},
  url = {https://doi.org/10.1145/3055004.3064845}
}
```
This work presents a platform for decentralized distributed computing called Resilient Information Architecture for the Smart Grid (RIAPS) through a transactional energy and a traffic application.
A. Laszka, A. Dubey, M. Walker, and D. C. Schmidt, Providing privacy, safety, and security in IoT-based transactive energy systems using distributed ledgers, in Proceedings of the Seventh International Conference on the Internet of Things, IOT 2017, Linz, Austria, October 22-25, 2017, 2017, pp. 13:1–13:8.
```
@inproceedings{Laszka2017,
  author = {Laszka, Aron and Dubey, Abhishek and Walker, Michael and Schmidt, Douglas C.},
  title = {Providing privacy, safety, and security in IoT-based transactive energy systems using distributed ledgers},
  booktitle = {Proceedings of the Seventh International Conference on the Internet of Things, {IOT} 2017, Linz, Austria, October 22-25, 2017},
  year = {2017},
  pages = {13:1--13:8},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/iot/LaszkaDWS17},
  category = {selectiveconference},
  doi = {10.1145/3131542.3131562},
  file = {:Laszka2017-Providing_privacy_safety_and_security_in_IoT-based_transactive_energy_systems_using_distributed_ledgers.pdf:PDF},
  keywords = {transactive, blockchain},
  project = {cps-reliability,cps-blockchains,transactive-energy},
  tag = {decentralization,power},
  timestamp = {Tue, 12 Nov 2019 00:00:00 +0100},
  url = {https://doi.org/10.1145/3131542.3131562}
}
```
Power grids are undergoing major changes due to rapid growth in renewable energy resources and improvements in battery technology. While these changes enhance sustainability and efficiency, they also create significant management challenges as the complexity of power systems increases. To tackle these challenges, decentralized Internet-of-Things (IoT) solutions are emerging, which arrange local communities into transactive microgrids. Within a transactive microgrid, “prosumers” (i.e., consumers with energy generation and storage capabilities) can trade energy with each other, thereby smoothing the load on the main grid using local supply. It is hard, however, to provide security, safety, and privacy in a decentralized and transactive energy system. On the one hand, prosumers’ personal information must be protected from their trade partners and the system operator. On the other hand, the system must be protected from careless or malicious trading, which could destabilize the entire grid. This paper describes Privacypreserving Energy of cyb (PETra), which is a secure and safe solution for transactive microgrids that enables consumers to trade energy without sacrificing their privacy. PETra builds on distributed ledgers, such as blockchains, and provides anonymity for communication, bidding, and trading.
S. Hasan, A. Chhokra, A. Dubey, N. Mahadevan, G. Karsai, R. Jain, and S. Lukic, A simulation testbed for cascade analysis, in IEEE Power & Energy Society Innovative Smart Grid Technologies Conference, ISGT 2017, Washington, DC, USA, April 23-26, 2017, 2017, pp. 1–5.
```
@inproceedings{Hasan2017,
  author = {Hasan, Saqib and Chhokra, Ajay and Dubey, Abhishek and Mahadevan, Nagabhushan and Karsai, Gabor and Jain, Rishabh and Lukic, Srdjan},
  title = {A simulation testbed for cascade analysis},
  booktitle = {{IEEE} Power {\&} Energy Society Innovative Smart Grid Technologies Conference, {ISGT} 2017, Washington, DC, USA, April 23-26, 2017},
  year = {2017},
  pages = {1--5},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/isgt/HasanCDMKJL17},
  category = {selectiveconference},
  doi = {10.1109/ISGT.2017.8086080},
  file = {:Hasan2017-A_simulation_testbed_for_cascade_analysis.pdf:PDF},
  keywords = {smartgrid},
  project = {cps-reliability},
  tag = {platform,power},
  timestamp = {Wed, 16 Oct 2019 14:14:57 +0200},
  url = {https://doi.org/10.1109/ISGT.2017.8086080}
}
```
Electrical power systems are heavily instrumented with protection assemblies (relays and breakers) that detect anomalies and arrest failure propagation. However, failures in these discrete protection devices could have inadvertent consequences, including cascading failures resulting in blackouts. This paper aims to model the behavior of these discrete protection devices in nominal and faulty conditions and apply it towards simulation and contingency analysis of cascading failures in power transmission systems. The behavior under fault conditions are used to identify and explain conditions for blackout evolution which are not otherwise obvious. The results are demonstrated using a standard IEEE-14 Bus System.
S. Eisele, I. Madari, A. Dubey, and G. Karsai, RIAPS: Resilient Information Architecture Platform for Decentralized Smart Systems, in 20th IEEE International Symposium on Real-Time Distributed Computing, ISORC 2017, Toronto, ON, Canada, May 16-18, 2017, 2017, pp. 125–132.
```
@inproceedings{Eisele2017b,
  author = {Eisele, Scott and Madari, Istv{\'{a}}n and Dubey, Abhishek and Karsai, Gabor},
  title = {{RIAPS:} Resilient Information Architecture Platform for Decentralized Smart Systems},
  booktitle = {20th {IEEE} International Symposium on Real-Time Distributed Computing, {ISORC} 2017, Toronto, ON, Canada, May 16-18, 2017},
  year = {2017},
  pages = {125--132},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/isorc/EiseleMDK17},
  category = {selectiveconference},
  doi = {10.1109/ISORC.2017.22},
  file = {:Eisele2017b-RIAPS_Resilient_Information_Architecture_Platform_for_Decentralized_Smart_Systems.pdf:PDF},
  keywords = {middleware},
  project = {smart-transit,smart-cities},
  tag = {platform,decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:53 +0200},
  url = {https://doi.org/10.1109/ISORC.2017.22}
}
```
The emerging Fog Computing paradigm provides an additional computational layer that enables new capabilities in real-time data-driven applications. This is especially interesting in the domain of Smart Grid as the boundaries between traditional generation, distribution, and consumer roles are blurring. This is a reflection of the ongoing trend of intelligence distribution in Smart Systems. In this paper, we briefly describe a component-based decentralized software platform called Resilient Information Architecture Platform for Smart Systems (RIAPS) which provides an infrastructure for such systems. We briefly describe some initial applications built using this platform. Then, we focus on the design and integration choices for a resilient Discovery Manager service that is a critical component of this infrastructure. The service allows applications to discover each other, work collaboratively, and ensure the stability of the Smart System.
K. Kvaternik, A. Laszka, M. Walker, D. C. Schmidt, M. Sturm, M. Lehofer, and A. Dubey, Privacy-Preserving Platform for Transactive Energy Systems, in preprint at arxiv, 2017, vol. abs/1709.09597.
```
@inproceedings{Kvaternik2017,
  author = {Kvaternik, Karla and Laszka, Aron and Walker, Michael and Schmidt, Douglas C. and Sturm, Monika and Lehofer, Martin and Dubey, Abhishek},
  title = {Privacy-Preserving Platform for Transactive Energy Systems},
  booktitle = {preprint at arxiv},
  year = {2017},
  volume = {abs/1709.09597},
  archiveprefix = {arXiv},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/corr/abs-1709-09597},
  eprint = {1709.09597},
  file = {:Kvaternik2017-Privacy_Preserving_Platform_for_Transactive_Energy_Systems.pdf:PDF},
  journal = {CoRR},
  keywords = {transactive},
  project = {transactive-energy,smart-energy},
  tag = {decentralization,power},
  timestamp = {Tue, 12 Nov 2019 00:00:00 +0100},
  url = {http://arxiv.org/abs/1709.09597}
}
```
Transactive energy systems (TES) are emerging as a transformative solution for the problems faced by distribution system operators due to an increase in the use of distributed energy resources and a rapid acceleration in renewable energy generation. These, on one hand, pose a decentralized power system controls problem, requiring strategic microgrid control to maintain stability for the community and for the utility. On the other hand, they require robust financial markets operating on distributed software platforms that preserve privacy. In this paper, we describe the implementation of a novel, blockchain-based transactive energy system. We outline the key requirements and motivation of this platform, describe the lessons learned, and provide a description of key architectural components of this system.
S. Hasan, A. Ghafouri, A. Dubey, G. Karsai, and X. Koutsoukos, Heuristics-based approach for identifying critical N-k contingencies in power systems, in 2017 Resilience Week (RWS), 2017, pp. 191–197.
```
@inproceedings{Hasan2017a,
  author = {{Hasan}, S. and {Ghafouri}, A. and Dubey, Abhishek and {Karsai}, G. and {Koutsoukos}, X.},
  title = {Heuristics-based approach for identifying critical N-k contingencies in power systems},
  booktitle = {2017 Resilience Week (RWS)},
  year = {2017},
  pages = {191-197},
  month = sep,
  category = {conference},
  doi = {10.1109/RWEEK.2017.8088671},
  file = {:Hasan2017a-Heuristics-based_approach_for_identifying_critical_N_k_contingencies_in_power_systems.pdf:PDF},
  issn = {null},
  keywords = {smartgrid},
  project = {cps-reliability,smart-energy},
  tag = {platform,power}
}
```
Reliable operation of electrical power systems in the presence of multiple critical N - k contingencies is an important challenge for the system operators. Identifying all the possible N - k critical contingencies to design effective mitigation strategies is computationally infeasible due to the combinatorial explosion of the search space. This paper describes two heuristic algorithms based on the iterative pruning of the candidate contingency set to effectively and efficiently identify all the critical N - k contingencies resulting in system failure. These algorithms are applied to the standard IEEE-14 bus system, IEEE-39 bus system, and IEEE-57 bus system to identify multiple critical N - k contingencies.
Y. Du, H. Tu, S. Lukic, D. Lubkeman, A. Dubey, and G. Karsai, Implementation of a distributed microgrid controller on the Resilient Information Architecture Platform for Smart Systems (RIAPS), in 2017 North American Power Symposium (NAPS), 2017, pp. 1–6.
```
@inproceedings{DuTu2017,
  author = {{Du}, Y. and {Tu}, H. and {Lukic}, S. and {Lubkeman}, D. and Dubey, Abhishek and {Karsai}, G.},
  title = {Implementation of a distributed microgrid controller on the Resilient Information Architecture Platform for Smart Systems (RIAPS)},
  booktitle = {2017 North American Power Symposium (NAPS)},
  year = {2017},
  pages = {1-6},
  month = sep,
  category = {selectiveconference},
  doi = {10.1109/NAPS.2017.8107305},
  file = {:DuTu2017-Implementation_of_a_distributed_microgrid_controller_on_RIAPS.pdf:PDF},
  issn = {null},
  keywords = {smartgrid},
  tag = {power}
}
```
Formation of microgrids have been proposed as a solution to improve grid reliability, and enable smoother integration of renewables into the grid. Microgrids are sections of the grid that can operate in isolation from the main power system. Maintaining power balance within an islanded microgrid is a challenging task, due to the low system inertia, which requires complex control to maintain stable and optimized operation. Many studies have demonstrated feasible distributed microgrid controllers that can maintain microgrid stability in grid connected and islanded modes. However, there is little emphasis on how to implement these distributed algorithms on a computational platform that allows for fast and seamless deployment. This paper introduces a decentralized software platform called Resilient Information Architecture Platform for Smart Systems (RIAPS) that runs on processors embedded with the microgrid component. As an example, we describe the implementation of a distributed microgrid secondary control and resynchronization algorithms on RIAPS platform. The controller developed on RIAPS platform is validated on a real-time microgrid testbed.
S. Hasan, A. Dubey, A. Chhokra, N. Mahadevan, G. Karsai, and X. Koutsoukos, A modeling framework to integrate exogenous tools for identifying critical components in power systems, in 2017 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2017, pp. 1–6.
```
@inproceedings{Hasan2017b,
  author = {{Hasan}, S. and Dubey, Abhishek and {Chhokra}, A. and {Mahadevan}, N. and {Karsai}, G. and {Koutsoukos}, X.},
  title = {A modeling framework to integrate exogenous tools for identifying critical components in power systems},
  booktitle = {2017 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES)},
  year = {2017},
  pages = {1-6},
  month = apr,
  category = {workshop},
  doi = {10.1109/MSCPES.2017.8064540},
  file = {:Hasan2017b-A_modeling_framework_to_integrate_exogenous_tools_for_identifying_critical_components_in_power_systems.pdf:PDF},
  keywords = {smartgrid},
  tag = {platform,power}
}
```
Cascading failures in electrical power systems are one of the major causes of concern for the modem society as it results in huge socio-economic loss. Tools for analyzing these failures while considering different aspects of the system are typically very expensive. Thus, researchers tend to use multiple tools to perform various types of analysis on the same system model in order to understand the reasons for these failures in detail. Modeling a simple system in multiple platforms is a tedious, error prone and time consuming process. This paper describes a domain specific modeling language (DSML) for power systems. It identifies and captures the right abstractions for modeling components in different analysis tools. A framework is proposed that deals with system modeling using the developed DSML, identifying the type of analysis to be performed, choosing the appropriate tool(s) needed for the analysis from the tool-chain, transforming the model based on the required specifications of a particular tool and performing the analysis. A case study is done on WSCC-9 Bus System, IEEE-14 Bus System and IEEE-39 Bus System to demonstrate the entire workflow of the framework in identifying critical components for power systems.
W. Emfinger, A. Dubey, P. Völgyesi, J. Sallai, and G. Karsai, Demo Abstract: RIAPS - A Resilient Information Architecture Platform for Edge Computing, in IEEE/ACM Symposium on Edge Computing, SEC 2016, Washington, DC, USA, October 27-28, 2016, 2016, pp. 119–120.
```
@inproceedings{Emfinger2016,
  author = {Emfinger, William and Dubey, Abhishek and V{\"{o}}lgyesi, P{\'{e}}ter and Sallai, J{\'{a}}nos and Karsai, Gabor},
  title = {Demo Abstract: {RIAPS} - {A} Resilient Information Architecture Platform for Edge Computing},
  booktitle = {{IEEE/ACM} Symposium on Edge Computing, {SEC} 2016, Washington, DC, USA, October 27-28, 2016},
  year = {2016},
  pages = {119--120},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/edge/EmfingerDVSK16},
  category = {poster},
  doi = {10.1109/SEC.2016.23},
  file = {:Emfinger2016-Demo_Abstract_RIAPS-A_Resilient_Information_Architecture_Platform_for_Edge_Computing.pdf:PDF},
  keywords = {middleware},
  project = {cps-middleware},
  tag = {platform,decentralization,power},
  timestamp = {Wed, 16 Oct 2019 14:14:56 +0200},
  url = {https://doi.org/10.1109/SEC.2016.23}
}
```
The emerging CPS/IoT ecosystem platforms such as Beaglebone Black, Raspberry Pi, Intel Edison and other edge devices such as SCALE, Paradrop are providing new capabilities for data collection, analysis and processing at the edge (also referred to as Fog Computing). This allows the dynamic composition of computing and communication networks that can be used to monitor and control the physical phenomena closer to the physical system. However, there are still a number of challenges that exist and must be resolved before we see wider applicability of these platforms for applications in safety-critical application domains such as Smart Grid and Traffic Control.
A. Dubey, S. Pradhan, D. C. Schmidt, S. Rusitschka, and M. Sturm, The Role of Context and Resilient Middleware in Next Generation Smart Grids, in Proceedings of the 3rd Workshop on Middleware for Context-Aware Applications in the IoT, M4IoT@Middleware 2016, Trento, Italy, December 12-13, 2016, 2016, pp. 1–6.
```
@inproceedings{Dubey2016,
  author = {Dubey, Abhishek and Pradhan, Subhav and Schmidt, Douglas C. and Rusitschka, Sebnem and Sturm, Monika},
  title = {The Role of Context and Resilient Middleware in Next Generation Smart Grids},
  booktitle = {Proceedings of the 3rd Workshop on Middleware for Context-Aware Applications in the IoT, M4IoT@Middleware 2016, Trento, Italy, December 12-13, 2016},
  year = {2016},
  pages = {1--6},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/middleware/DubeyPSRS16},
  category = {workshop},
  doi = {10.1145/3008631.3008632},
  file = {:Dubey2016-The_Role_of_Context_and_Resilient_Middleware_in_Next_Generation_Smart_Grids.pdf:PDF},
  keywords = {smartgrid, middleware},
  project = {cps-reliability,cps-middleware},
  tag = {platform,power},
  timestamp = {Tue, 06 Nov 2018 16:57:13 +0100},
  url = {https://doi.org/10.1145/3008631.3008632}
}
```
The emerging trends of volatile distributed energy resources and micro-grids are putting pressure on electrical power system infrastructure. This pressure is motivating the integration of digital technology and advanced power-industry practices to improve the management of distributed electricity generation, transmission, and distribution, thereby creating a web of systems. Unlike legacy power system infrastructure, however, this emerging next-generation smart grid should be context-aware and adaptive to enable the creation of applications needed to enhance grid robustness and efficiency. This paper describes key factors that are driving the architecture of smart grids and describes orchestration middleware needed to make the infrastructure resilient. We use an example of adaptive protection logic in smart grid substations as a use case to motivate the need for contextawareness and adaptivity.
H. Neema, W. Emfinger, and A. Dubey, A Reusable and Extensible Web-Based Co-Simulation Platform for Transactive Energy Systems, in Proceedings of the 3rd International Transactive Energy Systems, Portland, Oregon, USA, 2016, vol. 12.
```
@inproceedings{Neema2016,
  author = {Neema, Himanshu and Emfinger, William and Dubey, Abhishek},
  title = {A Reusable and Extensible Web-Based Co-Simulation Platform for Transactive Energy Systems},
  booktitle = {Proceedings of the 3rd International Transactive Energy Systems, Portland, Oregon, USA},
  year = {2016},
  volume = {12},
  category = {workshop},
  file = {:Neema2016-A_Reusable_and_Extensible_Web-Based_Co-Simulation_Platform_for_Transactive_Energy_Systems.pdf:PDF},
  keywords = {transactive},
  tag = {platform,power}
}
```
Rapid evolution of energy generation technology and increased used of distributed energy resources (DER) is continually pushing utilities to adapt and evolve business models to align with these changes. Today, more consumers are also producing energy using green generation technologies and energy pricing is becoming rather competitive and transactional, needing utilities to increase flexibility of grid operations and incorporate transactive energy systems (TES). However, a huge bottleneck is to ensure stable grid operations while gaining efficiency. A comprehensive platform is therefore needed for grid-scale multi-aspects integrated evaluations. For instance, cyber-attacks in a road traffic controller’s communication network can subtly divert electric vehicles in a particular area, causing surge in the grid loads due to increased EV charging and people activity, which can potentially disrupt, an otherwise robust, grid. To evaluate such a scenario, multiple special-purpose simulators (e.g., SUMO, OMNeT++, GridlabD, etc.) must be run in an integrated manner. To support this, we are developing a cloud-deployed web- and model-based simulation integration platform that enables integrated evaluations of transactive energy systems and is highly extensible and customizable for utility-specific custom simulation tools.
N. Mahadevan, A. Dubey, A. Chhokra, H. Guo, and G. Karsai, Using temporal causal models to isolate failures in power system protection devices, IEEE Instrum. Meas. Mag., vol. 18, no. 4, pp. 28–39, 2015.
```
@article{Mahadevan2015,
  author = {Mahadevan, Nagabhushan and Dubey, Abhishek and Chhokra, Ajay and Guo, Huangcheng and Karsai, Gabor},
  title = {Using temporal causal models to isolate failures in power system protection devices},
  journal = {{IEEE} Instrum. Meas. Mag.},
  year = {2015},
  volume = {18},
  number = {4},
  pages = {28--39},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/imm/MahadevanDCGK15},
  doi = {10.1109/MIM.2015.7155770},
  file = {:Mahadevan2015-Using_temporal_causal_models_to_isolate_failures_in_power_system_protection_devices.pdf:PDF},
  keywords = {smartgrid, reliability},
  project = {cps-reliability,smart-energy},
  tag = {platform,power},
  timestamp = {Sun, 28 May 2017 01:00:00 +0200},
  url = {https://doi.org/10.1109/MIM.2015.7155770}
}
```
We introduced the modeling paradigm of Temporal Causal Diagrams (TCD) in this paper. TCDs capture fault propagation and behavior (nominal and faulty) of system components. An example model for the power transmission systems was also described. This TCD model was then used to develop an executable simulation model in Simulink/ Stateflow. Though this translation of TCD to an executable model is currently done manually, we are developing model templates and tools to automate this process. Simulations results (i.e., event traces) for a couple of single and multi-fault scenarios were also presented. As part of our future work, we wish to test and study the scalability of this approach towards a larger power transmission system taking into account a far richer set of protection elements. Further, we wish to consider more realistic event traces from the fault scenarios including missing, inconsistent and out-of-sequence alarms and events.
R. Jain, S. M. Lukic, A. Chhokra, N. Mahadevan, A. Dubey, and G. Karsai, An improved distance relay model with directional element, and memory polarization for TCD based fault propagation studies, in 2015 North American Power Symposium (NAPS), 2015, pp. 1–6.
```
@inproceedings{Jain2015,
  author = {{Jain}, R. and {Lukic}, S. M. and {Chhokra}, A. and {Mahadevan}, N. and Dubey, Abhishek and {Karsai}, G.},
  title = {An improved distance relay model with directional element, and memory polarization for TCD based fault propagation studies},
  booktitle = {2015 North American Power Symposium (NAPS)},
  year = {2015},
  pages = {1-6},
  month = oct,
  category = {selectiveconference},
  doi = {10.1109/NAPS.2015.7335206},
  file = {:Jain2015-An_improved_distance_relay_model_with_directional_element_and_memory_polarization_for_TCD_based_fault_propagation_studies.pdf:PDF},
  issn = {null},
  keywords = {smartgrid},
  tag = {power}
}
```
Modern Power Systems have evolved into a very complex network of multiple sources, lines, breakers, loads and others. The performance of these interdependent components decide the reliability of the power systems. A tool called “Reasoner” is being developed to deduce fault propagations using a Temporal Causal Diagram (TCD) approach. It translates the physical system as a Cause-effect model. This work discusses the development of an advanced distance relay model, which monitors the system, and challenges the operation of reasoner for refinement. Process of generation of a Fault and Discrepancy Mapping file from the test system is presented. This file is used by the reasoner to scrutinize relays’ responses for active system faults, and hypothesize potential mis-operations (or cyber faults) with a confidence metric. Analyzer (relay model) is integrated to OpenDSS for fault analysis. The understanding of the system interdependency (fault propagation behavior) using reasoner can make the grid more robust against cascaded failures.
A. Chhokra, A. Dubey, N. Mahadevan, and G. Karsai, A component-based approach for modeling failure propagations in power systems, in 2015 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2015, pp. 1–6.
```
@inproceedings{Chhokra2015a,
  author = {{Chhokra}, A. and Dubey, Abhishek and {Mahadevan}, N. and {Karsai}, G.},
  title = {A component-based approach for modeling failure propagations in power systems},
  booktitle = {2015 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES)},
  year = {2015},
  pages = {1-6},
  month = apr,
  category = {workshop},
  doi = {10.1109/MSCPES.2015.7115412},
  file = {:Chhokra2015a-A_component-based_approach_for_modeling_failure_propagations_in_power_systems.pdf:PDF},
  keywords = {smartgrid},
  tag = {platform,power}
}
```
Resiliency and reliability is of paramount impor- tance for energy cyber physical systems. Electrical protection systems including detection elements such as Distance Relays and actuation elements such as Breakers are designed to protect the system from abnormal operations and arrest failure propagation by rapidly isolating the faulty components. However, failure in the protection devices themselves can and do lead to major system events and fault cascades, often leading to blackouts. This paper augments our past work on Temporal Causal Diagrams (TCD), a modeling formalism designed to help reason about the failure progressions by (a) describing a way to generate the TCD model from the system specification, and (b) understand the system failure dynamics for TCD reasoners by configuring simulation models.
N. Mahadevan, A. Dubey, G. Karsai, A. Srivastava, and C.-C. Liu, Temporal Causal Diagrams for diagnosing failures in cyber-physical systems, in Annual Conference of the Prognostics and Health Management Society, 2014.
```
@inproceedings{Mahadevan2014,
  author = {Mahadevan, Nagabhushan and Dubey, Abhishek and Karsai, Gabor and Srivastava, Anurag and Liu, Chen-Ching},
  title = {Temporal Causal Diagrams for diagnosing failures in cyber-physical systems},
  booktitle = {Annual Conference of the Prognostics and Health Management Society},
  year = {2014},
  month = jan,
  category = {conference},
  file = {:Mahadevan2014-Temporal_Causal_Diagrams_for_Diagnosing_Failures_in_Cyber_Physical_Systems.pdf:PDF},
  keywords = {reliability, smartgrid},
  tag = {platform,power}
}
```
Resilient and reliable operation of cyber physical systems of societal importance such as Smart Electric Grids is one of the top national priorities. Due to their critical nature, these systems are equipped with fast-acting, local protection mechanisms. However, commonly misguided protection actions together with system dynamics can lead to un-intentional cascading effects. This paper describes the ongoing work using Temporal Causal Diagrams (TCD), a refinement of the Timed Failure Propagation Graphs (TFPG), to diagnose problems associated with the power transmission lines protected by a combination of relays and breakers. The TCD models represent the faults and their propagation as TFPG, the nominal and faulty behavior of components (including local, discrete controllers and protection devices) as Timed Discrete Event Systems (TDES), and capture the cumulative and cascading effects of these interactions. The TCD diagnosis engine includes an extended TFPG-like reasoner which in addition to observing the alarms and mode changes (as the TFPG), monitors the event traces (that correspond to the behavioral aspects of the model) to generate hypotheses that consistently explain all the observations. In this paper, we show the results of applying the TCD to a segment of a power transmission system that is protected by distance relays and breakers.
J. Shi, R. Amgai, S. Abdelwahed, A. Dubey, J. Humphreys, M. Alattar, and R. Jia, Generic modeling and analysis framework for shipboard system design, in 2013 IEEE Electric Ship Technologies Symposium (ESTS), 2013, pp. 420–428.
```
@inproceedings{Shi2013,
  author = {{Shi}, J. and {Amgai}, R. and {Abdelwahed}, S. and Dubey, Abhishek and {Humphreys}, J. and {Alattar}, M. and {Jia}, R.},
  title = {Generic modeling and analysis framework for shipboard system design},
  booktitle = {2013 IEEE Electric Ship Technologies Symposium (ESTS)},
  year = {2013},
  pages = {420-428},
  month = apr,
  category = {workshop},
  doi = {10.1109/ESTS.2013.6523770},
  file = {:Shi2013-Generic_modeling_and_analysis_framework_for_shipboard_system_design.pdf:PDF},
  issn = {null},
  keywords = {middleware},
  tag = {platform,power}
}
```
This paper proposes a novel modeling and simulation environment for ship design based on the principles of Model Integrated Computing (MIC). The proposed approach facilitates the design and analysis of shipboard power systems and similar systems that integrate components from different fields of expertise. The conventional simulation platforms such as Matlab\textregistered, Simulink\textregistered, PSCAD\textregistered and VTB\textregistered require the designers to have explicit knowledge of the syntactic and semantic information of the desired domain within the tools. This constraint, however, severely slows down the design and analysis process, and causes cross-domain or cross-platform operations remain error prone and expensive. Our approach focuses on the development of a modeling environment that provides generic support for a variety of application across different domains by capturing modeling concepts, composition principles and operation constraints. For the preliminary demonstration of the modeling concept, in this paper we limit the scope of design to cross-platform implementations of the proposed environment by developing an application model of a simplified shipboard power system and using Matlab engine and VTB solver separately to evaluate the performance with different respects. In the case studies a fault scenario is pre-specified and tested on the system model. The corresponding time domain bus voltage magnitude and angle profiles are generated via invoking external solver, displayed to users and then saved for future analysis.

ScopeLab - Design, Operation and Optimization of Smart Cyber-Physical Systems

Smart Power Grids

Publications in this area

ScopeLab
- Design, Operation and Optimization of Smart Cyber-Physical Systems