Security Improvement of Power System Via Resilience-oriented Planning and Operation
Author: Kexing Lai
Publisher:
Published: 2019
Total Pages: 157
ISBN-13:
DOWNLOAD EBOOKIn this dissertation, I will discuss methods to mitigate detrimental effects of malicious attacks on electric power systems. My work is motivated by the growing concern over security of electric power delivery due to intentional/terrorist attacks, which imposes urgency to upgrade for resiliency. In the second chapter, I present my research works on hedging against attacks on transmission lines by proposing a resilience-oriented transmission system operation model. I developed a tri-level optimization problem to model interactions between the operator and the attacker. The proposed optimization model will identify the operation strategy allowing for the minimum load shedding with attacks in the worst-case scenario. In the third chapter, I introduce a distributed energy management strategy for a zonal shipboard power system for enhanced resilience against contingencies. A modified nested energy management method is proposed for decentralizing energy scheduling to prevent entire system collapse caused by single-node failure. Furthermore, the system resilience is enhanced against energy deficiency due to generators failures by reserving more energy in the energy storage system. This is achieved by applying a distributed algorithm, known as alternating direction method of multiplier, to coordinate involved operators with contradicting objectives. In the fourth chapter, I provide a solution for the optimal defending resource allocation to mitigate the impacts of coordinated cyber-physical attacks. The coordinated attack involves physical short-circuiting of transmission lines after intruding the communication network of protection relays. A tri-level optimization model is proposed to formulate the coordinated attack scenario and identify the optimal defending strategy. In the fifth chapter, I present a graph theory-based power line expansion strategy for a medium voltage direct current (MVDC) shipboard power system. The proposed strategy simultaneously maximizes the algebraic connectivity and weighted max-flow from generator nodes to load nodes in the graphical representation of the shipboard power system. Finally, I summarize my contributions during my Ph.D. program and provide suggestions for the future research works.