Gaoqi Liang

A Review of False Data Injection Attacks Against Modern Power Systems

With rapid advances in sensor, computer, and communication networks, modern power systems have become complicated cyber-physical systems. Assessing and enhancing cyber-physical system security is, therefore, of utmost importance for the future electricity grid. In a successful false data injection attack (FDIA), an attacker compromises measurements from grid sensors in such a way that undetected errors are introduced into estimates of state variables such as bus voltage angles and magnitudes. In evading detection by commonly employed residue-based bad data detection tests, FDIAs are capable of severely threatening power system security. Since the first published research on FDIAs in 2009, research into FDIA-based cyber-attacks has been extensive. This paper gives a comprehensive review of state-of-the-art in FDIAs against modern power systems. This paper first summarizes the theoretical basis of FDIAs, and then discusses both the physical and the economic impacts of a successful FDIA. This paper presents the basic defense strategies against FDIAs and discusses some potential future research directions in this field.

The 2015 Ukraine Blackout: Implications for False Data Injection Attacks

In a false data injection attack (FDIA), an adversary stealthily compromises measurements from electricity grid sensors in a coordinated fashion, with a view to evading detection by the power system bad data detection module. A successful FDIA can cause the system operator to perform control actions that compromise either the physical or economic operation of the power system. In this letter, we consider some implications for FDIAs arising from the late 2015 Ukraine Blackout event.

Multiagent-Based Cooperative Control Framework for Microgrids’ Energy Imbalance

This paper proposes a cooperative control framework for the coordination of multiple microgrids. The framework is based on the multiagent system. The control framework aims to encourage the resource sharing among different autonomous microgrids and solve the energy imbalance problems by forming the microgrid coalition self-adaptively. First, the conceptual model of the integrated microgrids and the layered cooperative control framework is presented. Then, an advanced dynamic coalition formation scheme and corresponding negotiation algorithm are introduced to model the coordination behaviors of the microgrids. The proposed control framework is implemented by the Java Agent Development Framework. A loop distribution system with multiple interconnected microgrids is simulated, and the case studies are conducted to prove the efficiency of the proposed framework.

Generalized FDIA-Based Cyber Topology Attack With Application to the Australian Electricity Market Trading Mechanism

This paper proposes a generalized false data injection attack-based cyber topology attack capable of disturbing conventional transactions in the electricity market. The proposed attack aims to mislead customers pay higher electricity bills in the wholesale market by making small, undetected price deviations during each attack interval over an extended period. In this paper, the Australian electricity market trading mechanism is considered, in which an extended attack over a single day is proposed, spanning totally 288 5-minute dispatch (attack) intervals. The proposed attack poses no security threat to the power system, affecting only the economic costs borne by customers. A defining feature of the proposed model is the joint consideration of both topology error processing and bad data detection constraints in order to ensure validity of the proposed attack. The rolling horizon optimization technique is used to make appropriate adjustment to the attacker’s strategy considering the practical operating condition. A new metaheuristic optimization algorithm previously proposed by the authors, Natural aggregation algorithm, is used to find the corresponding attack strategies in this paper. Case studies on the IEEE-118 benchmark system are conducted to validate the proposed attack methodology.

A Framework for Cyber-topology Attacks: Line-switching and New Attack Scenarios

Cyber security of modern power systems has drawn increasing attention in recent years. This paper proposes a class of cyber-topology attacks derived from false data injection attacks, with the aim of disturbing the operation of power systems. Three kinds of cyber-topology attack are proposed: 1) line-addition attack; 2) line-removal attack; and 3) line-switching attack. By directly misleading the decision-making process of the independent system operator, the proposed cyber-topology attack consequently affects the economic operation and security of the system. We establish optimal attack models for different cyber-topology attack scenarios, and use a recently proposed metaheuristic optimization algorithm the natural aggregation algorithm to solve the resulting attack models. Experiments based on the IEEE 39-node benchmark system show that the proposed class of attacks poses a significant threat to modern power systems.

Optimal wind turbine and air conditioner loads control in distribution networks through MILP approach

This paper considers two important challenges in the distribution network with high renewable penetrations. One is that during the peak load, generation is normally low or zero and it will cause the voltage drop. Meanwhile, during peak generation period, the generated power will exceed the load and be injected to the grid, which will subsequently cause the voltage rise. This paper proposes a MILP (Mixed Integer Linear Programming) approach to accommodate more wind generation in distribution networks. By coordinating the status of controllable load, battery energy storage system (BESS) and wind power, this paper proposes an optimal scheduling model for the distribution system to minimize the total costs from grid. Rolling optimization and weighting factor were implemented to obtain a good operation strategy under real-time operation. Detailed case studies are conducted to demonstrate the feasibility of the proposed method.