- Design, Operation and Optimization of Smart Cyber-Physical Systems
Augmenting and Advancing Cognitive Performance of Control Room Operators for Power Grid Resiliency
The goal of the project is to investigate the mechanisms required to integrate recent advances from cognitive neuroscience, artificial intelligence, machine learning, data science, cybersecurity, and power engineering to augment power grid operators for better performance. Two key parameters influencing human performance from the dynamic attentional control (DAC) framework are working memory (WM) capacity, the ability to maintain information in the focus of attention, and cognitive flexibility (CF), the ability to use feedback to redirect decision making given fast changing system scenarios. The project will achieve its goals through analyzing WM and CF and performance of power grid operators during extreme events; augmenting cognitive performance through advanced machine learning based decision support tools and adaptive human-machine system; and developing theory-driven training simulators for advancing cognitive performance of human operators for enhanced grid resilience. We are building a new set of algorithms for data-driven event detection, anomaly flag processing, root cause analysis and decision support using Tree Augmented naive Bayesian Net (TAN) structure, Minimum Weighted Spanning Tree (MWST) using the Mutual Information (MI) metric, and unsupervised learning improved for online learning and decision making. In addition we use a discrete event model that captures the causal and temporal relationships between failure modes (causes) and discrepancies (effects) in a system, thereby modeling the failure cascades while taking into account propagation constraints imposed by operating modes, protection elements, and timing delays. This formalism is called Temporal Causal Diagram (TCD) and can model the effects of faults and protection mechanisms as well as incorporate fine-grain, physics-based diagnostics into an integrated, system-level diagnostics scheme. This project is in collaboration with Prof. Gautam Biswas from ISIS and Prof. Anurag Srivastava from Washington State University.
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.
H. Tu, Y. Du, H. Yu, A. Dubey, S. Lukic, and G. Karsai, Resilient Information Architecture Platform for the Smart Grid: A Novel Open-Source Platform for Microgrid Control, IEEE Transactions on Industrial Electronics, vol. 67, no. 11, pp. 9393–9404, 2020.
@article{riaps2020,
author = {{Tu}, H. and {Du}, Y. and {Yu}, H. and {Dubey}, Abhishek and {Lukic}, S. and {Karsai}, G.},
journal = {IEEE Transactions on Industrial Electronics},
title = {Resilient Information Architecture Platform for the Smart Grid: A Novel Open-Source Platform for Microgrid Control},
year = {2020},
volume = {67},
tag = {platform},
number = {11},
pages = {9393-9404}
}
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 article, 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.
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.
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. 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
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.
P. Ghosh, S. Eisele, A. Dubey, M. Metelko, I. Madari, P. Volgyesi, and G. Karsai, Designing a decentralized fault-tolerant software framework for smart grids and its applications, Journal of Systems Architecture, vol. 109, p. 101759, 2020.
@article{GHOSH2020101759,
author = {Ghosh, Purboday and Eisele, Scott and Dubey, Abhishek and Metelko, Mary and Madari, Istvan and Volgyesi, Peter and Karsai, Gabor},
title = {Designing a decentralized fault-tolerant software framework for smart grids and its applications},
journal = {Journal of Systems Architecture},
year = {2020},
volume = {109},
pages = {101759},
tag = {platform},
issn = {1383-7621},
doi = {https://doi.org/10.1016/j.sysarc.2020.101759},
keywords = {Component, Fault tolerance, Distributed systems, Smart grid},
url = {http://www.sciencedirect.com/science/article/pii/S1383762120300539}
}
The vision of the ‘Smart Grid’ anticipates 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 of 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. 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. 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.
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.
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.
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.
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.
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, 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. Kulkarni, S. Hasan, A. Dubey, N. Mahadevan, and G. Karsai, A Systematic Approach of Identifying Optimal Load Control Actions for Arresting Cascading Failures in Power Systems, in Proceedings of the 2nd Workshop on Cyber-Physical Security and Resilience in Smart Grids, SPSR-SG@CPSWeek 2017, Pittsburgh, PA, USA, April 21, 2017, 2017, pp. 41–46.
@inproceedings{Chhokra2017,
author = {Chhokra, Ajay and Kulkarni, Amogh and Hasan, Saqib and Dubey, Abhishek and Mahadevan, Nagabhushan and Karsai, Gabor},
title = {A Systematic Approach of Identifying Optimal Load Control Actions for Arresting Cascading Failures in Power Systems},
booktitle = {Proceedings of the 2nd Workshop on Cyber-Physical Security and Resilience in Smart Grids, SPSR-SG@CPSWeek 2017, Pittsburgh, PA, USA, April 21, 2017},
year = {2017},
tag = {platform},
pages = {41--46},
bibsource = {dblp computer science bibliography, https://dblp.org},
biburl = {https://dblp.org/rec/bib/conf/cpsweek/ChhokraKHDMK17},
category = {workshop},
doi = {10.1145/3055386.3055395},
file = {:Chhokra2017-A_Systematic_Approach_of_Identifying_Optimal_Load_Control_Actions_for_Arresting_Cascading_Failures_in_Power_Systems.pdf:PDF},
keywords = {reliability, smartgrid},
project = {cps-reliability},
timestamp = {Tue, 06 Nov 2018 16:59:05 +0100},
url = {https://doi.org/10.1145/3055386.3055395}
}
Cascading outages in power networks cause blackouts which lead to huge economic and social consequences. The traditional form of load shedding is avoidable in many cases by identifying optimal load control actions. However, if there is a change in the system topology (adding or removing loads, lines etc), the calculations have to be performed again. This paper addresses this problem by providing a workflow that 1) generates system models from IEEE CDF specifications, 2) identifies a collection of blackout causing contingencies, 3) dynamically sets up an optimization problem, and 4) generates a table of mitigation strategies in terms of minimal load curtailment. We demonstrate the applicability of our proposed methodology by finding load curtailment actions for N-k contingencies (k = 1, 2, 3) in IEEE 14 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. 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. 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.
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.
A. Chhokra, A. Dubey, N. Mahadevan, and G. Karsai, Poster Abstract: Distributed Reasoning for Diagnosing Cascading Outages in Cyber Physical Energy Systems, in 7th ACM/IEEE International Conference on Cyber-Physical Systems, ICCPS 2016, Vienna, Austria, April 11-14, 2016, 2016, p. 33:1.
@inproceedings{Chhokra2016,
author = {Chhokra, Ajay and Dubey, Abhishek and Mahadevan, Nagabhushan and Karsai, Gabor},
title = {Poster Abstract: Distributed Reasoning for Diagnosing Cascading Outages in Cyber Physical Energy Systems},
booktitle = {7th {ACM/IEEE} International Conference on Cyber-Physical Systems, {ICCPS} 2016, Vienna, Austria, April 11-14, 2016},
year = {2016},
pages = {33:1},
tag = {platform},
bibsource = {dblp computer science bibliography, https://dblp.org},
biburl = {https://dblp.org/rec/bib/conf/iccps/ChhokraDMK16},
category = {poster},
doi = {10.1109/ICCPS.2016.7479113},
file = {:Chhokra2016-Poster_Abstract_Distributed_Reasoning_for_Diagnosing_Cascading_Outages_in_Cyber_Physical_Energy_Systems.pdf:PDF},
keywords = {smartgrid},
project = {cps-reliability},
timestamp = {Wed, 16 Oct 2019 14:14:57 +0200},
url = {https://doi.org/10.1109/ICCPS.2016.7479113}
}
The power grid incorporates a number of protection elements such as distance relays that detect faults and prevent the propagation of failure effects from influencing the rest of system. However, the decision of these protection elements is only influenced by local information in the form of bus voltage/current (V-I) samples. Due to lack of system wide perspective, erroneous settings, and latent failure modes, protection devices often mis-operate and cause cascading effects that ultimately lead to blackouts. Blackouts around the world have been triggered or worsened by circuit breakers tripping, including the blackout of 2003 in North America, where the secondary/ remote protection relays incorrectly opened the breaker. Tools that aid the operators in finding the root cause of the problem on-line are required. However, high system complexity and the interdependencies between the cyber and physical elements of the system and the mis-operation of protection devices make the failure diagnosis a challenging problem.
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.