Effects of Cyber Attacks on AC and High-Voltage DC Interconnected Power Systems with Emulated Inertia

Kaikai Pan,Elyas Rakhshani,Jingwei Dong,Peter Palensky

doi:10.3390/en13215583

Abstract

The high penetration of renewable energy resources and power electronic-based components has led to a low-inertia power grid which would bring challenges to system operations. The new model of load frequency control (LFC) must be able to handle the modern scenario where controlled areas are interconnected by parallel AC/HVDC links and storage devices are added to provide virtual inertia. Notably, vulnerabilities within the communication channels for wide-area data exchange in LFC loops may make them exposed to various cyber attacks, while it still remains largely unexplored how the new LFC in the AC/HVDC interconnected system with emulated inertia would be affected under malicious intrusions. Thus, in this article, we are motivated to explore possible effects of the major types of data availability and integrity attacks—Denial of Service (DoS) and false data injection (FDI) attacks—on such a new LFC system. By using a system-theoretic approach, we explore the optimal strategies that attackers can exploit to launch DoS or FDI attacks to corrupt the system stability. Besides, a comparison study is performed to learn the impact of these two types of attacks on LFC models of power systems with or without HVDC link and emulated inertia. The simulation results on the the exemplary two-area system illustrate that both DoS and FDI attacks can cause large frequency deviations or even make the system unstable; moreover, the LFC system with AC/HVDC interconnections and emulated inertia could be more vulnerable to these two types of attacks in many adversarial scenarios.

Highlights

In the modern power systems, there is an increasing attention on the integration of renewable energy resources (RES), energy storage devices, and high voltage direct-current (HVDC) links
We evaluate the effects of false data injection (FDI) attacks on the three load frequency control (LFC) system models
We can see that regarding the attack impact index of maximum frequency deviation (MFD) during the transients, there would be a larger MFD in the LFC of the system interconnected by AC/HVDC lines and equipped with energy storage systems (ESS) to emulate inertia

Summary

Introduction

In the modern power systems, there is an increasing attention on the integration of renewable energy resources (RES), energy storage devices, and high voltage direct-current (HVDC) links. The conventional control scheme such as the load frequency control (LFC) is adapting to handle the new scenario where controlled areas are interconnected by parallel alternating-current (AC) and HVDC transmission lines and energy storage systems (ESS) are added for emulating virtual inertia. This transformation has introduced a high dependence on data communications, as the control loops involved in the new LFC would use communication networks such as the supervisory control and data acquisition (SCADA) system to transmit measurements and control data. It has been reported that the conventional LFC loops of multi-area systems with pure AC interconnections can be vulnerable to a large number of malicious intrusions [7,8].

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