Subhash Lakshminarayana

Dr. Subhash Lakshminarayana

School of Engineering, University of Warwick, UK

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 November 2023 in Solar Energy
Verified
Journal Article
Open access
UHUla Hijjawi
Ula Hijjawi
Subhash LakshminarayanaSubhash Lakshminarayana
Subhash Lakshminarayana
TXTianhua Xu
Tianhua Xu
GFGian Piero Malfense Fierro
Gian Piero Malfense Fierro
MRMostafizur Rahman
Mostafizur Rahman

23 July 2020 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
Subhash LakshminarayanaSubhash Lakshminarayana
Subhash Lakshminarayana
AKAbla Kammoun
Abla Kammoun
MDMerouane Debbah
Merouane Debbah
H. Vincent PoorH. Vincent Poor
H. Vincent Poor
We address the problem of constructing false data injection (FDI) attacks that can bypass the bad data detector (BDD) of a power grid. The attacker is assumed to have access to only power grid measurement data traces collected over a limited period of time and no other prior knowledge about the grid. Existing related algorithms are formulated under the assumption that the attacker has access to measurements collected over a long (asymptotically infinite) time period, which may not be realistic. We show that these approaches do not perform well when the attacker has access to measurements from a limited time window only. We design an enhanced algorithm to construct FDI attack vectors in the face of limited measurements that can nevertheless bypass the BDD with high probability. The algorithm design is guided by results from random matrix theory. Furthermore, we characterize an important trade-off between the attack’s BDD-bypass probability and its sparsity, which affects the spatial extent of the attack that must be achieved. Extensive simulations using data traces collected from the MATPOWER simulator and benchmark IEEE bus systems validate our findings.

6 July 2021 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
Subhash LakshminarayanaSubhash Lakshminarayana
Subhash Lakshminarayana
EBE. Veronica Belmega
E. Veronica Belmega
H. Vincent PoorH. Vincent Poor
H. Vincent Poor
This work proposes a moving target defense (MTD) strategy to detect coordinated cyber-physical attacks (CCPAs) against power grids. The main idea of the proposed approach is to invalidate the knowledge that the attackers use to mask the effects of their physical attack by actively perturbing the grid’s transmission line reactances via distributed flexible AC transmission system (D-FACTS) devices. The proposed MTD design consists of two parts. First, we identify the subset of links for D-FACTS device deployment that enables the defender to detect CCPAs against any link in the system. Then, in order to minimize the defense cost during the system’s operational time, we formulate a zero-sum game to identify the best subset of links to perturb (which will provide adequate protection) against a strategic attacker. The Nash equilibrium robust solution is computed via exponential weights, which does not require complete knowledge of the game but only the observed payoff at each iteration. Extensive simulations performed using the MATPOWER simulator on IEEE bus systems verify the effectiveness of our approach in detecting CCPAs and reducing the operator’s defense cost.

3 February 2025 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
IZIoannis Zografopoulos
Ioannis Zografopoulos
ASAnkur Srivastava
Ankur Srivastava
CKCharalambos Konstantinou
Charalambos Konstantinou
JZJunbo Zhao
Junbo Zhao
AJAmir Abiri Jahromi
Amir Abiri Jahromi
ZWZhaoyuan Wang
Zhaoyuan Wang
This paper summarizes the technical endeavors undertaken by the Task Force (TF) on Cyber-Physical Interdependence for Power System Operation and Control. The TF was established to investigate the cyber-physical interdependence of critical power system elements and their influence on the operation and control of energy systems. State-of-the-art analysis techniques, including co-simulation and digital twin technologies, are employed to address various layers of interdependence between cyber and physical systems, facilitating the identification of potential threats and vulnerabilities. The paper examines prospective trajectories for resilient cyber-physical systems and outlines the educational and workforce training imperatives for addressing cybersecurity threats in contemporary power systems. Furthermore, concluding remarks and future recommendations are provided to mitigate the inherent vulnerabilities within the extensively interoperable grid infrastructure.

1 April 2021 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
Subhash LakshminarayanaSubhash Lakshminarayana
Subhash Lakshminarayana
SASondipon Adhikari
Sondipon Adhikari
CMCasten Maple
Casten Maple
Recent research has shown that large-scale Internet of Things (IoT)-based load altering attacks can have a serious impact on power grid operations such as causing unsafe frequency excursions and destabilizing the grid's control loops. In this work, we present an analytical framework to investigate the impact of IoT-based static/dynamic load altering attacks (S/DLAAs) on the power grid's dynamic response. Existing work on this topic has mainly relied on numerical simulations and, to date, there is no analytical framework to identify the victim nodes from which that attacker can launch the most impactful attacks. To address these shortcomings, we use results from second-order dynamical systems to analyze the power grid frequency control loop under S/DLAAs. We use parametric sensitivity of the system's eigensolutions to identify victim nodes that correspond to the least-effort destabilizing DLAAs. Further, to analyze the SLAAs, we present closed-form expression for the system's frequency response in terms of the attacker's inputs, helping us characterize the minimum load change required to cause unsafe frequency excursions. Using these results, we formulate the defense against S/DLAAs as a linear programming problem in which we determine the minimum amount of load that needs to be secured at the victim nodes to ensure system safety/stability. Extensive simulations conducted using benchmark IEEE-bus systems validate the accuracy and efficacy of our approach.

22 December 2022 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
ZCZhongda Chu
Zhongda Chu
Subhash LakshminarayanaSubhash Lakshminarayana
Subhash Lakshminarayana
BCBalarko Chaudhuri
Balarko Chaudhuri
FTFei Teng
Fei Teng
Large-scale Load-Altering Attacks (LAAs) against Internet-of-Things (IoT) enabled high-wattage electrical appliances pose a serious threat to power system security and stability. This paper investigates, for the first time, the optimal mitigation strategy from a system perspective against such attacks. In particular, a Cyber-Resilient Economic Dispatch (CRED) concept is proposed and seamlessly integrated with attack detection and identification to form a cyber resiliency enhancement framework. Instead of only relying on local resources, CRED coordinates the frequency droop control gains of Inverter-Based Resources (IBRs) in the system to mitigate the destabilizing effect of LAAs while minimizing the overall operational cost. To achieve this, the LAA-inclusive system frequency dynamics is formulated and the corresponding system stability constraints are explicitly derived based on parametric sensitivities, which are further incorporated into the system scheduling model with minimum error through a novel recursive linearization method. In addition, a distributionally robust approach is proposed to account for the uncertainty associated with system dynamics driven by the LAA detection/parameter estimation errors. The overall performance of the proposed CRED model is demonstrated through extensive simulations in a modified IEEE reliability test system.