Vulnerability Assessment of Conservation Voltage Reduction to Load Redistribution Attack in Unbalanced Active Distribution Networks

Abstract

This article proposes a new type of load redistribution attack on a closed-loop conservation voltage reduction (CVR) in an unbalanced three-phase distribution network having voltage regulators (an on-load tap changer (OLTC) and capacitor bank), smart inverters for solar photovoltaic and energy storage systems, and smart meters. The objective of the proposed attack strategy using a bilevel optimization problem is to maximize three-phase active power flow from the substation (upper level) while guaranteeing normal CVR operation (lower level) through the injection of malicious data into smart meters. The bilevel optimization problem is finally transformed into a single-level optimization problem based on Karush-Kuhn-Tucker conditions of the lower level optimization problem. An IEEE 13-node distribution feeder is used to quantify the performance of the proposed attack in terms of voltage level, OLTC tap position, PV penetration rate, and attack effort.