Enhancing long-term voltage stability of a power system integrated with large-scale photovoltaic plants using a battery energy storage control scheme

Abstract

Due to distinct differences in dynamic characteristics of large-scale photovoltaic plants (LS-PVPs) compared to conventional generation units, utilities face some new non-traditional operational problems, more specifically in terms of voltage stability. This paper analyzes the impact of various control methods of LS-PVPs on long-term (LT) voltage stability. A new corrective voltage control (CVC) scheme is proposed for the large-scale battery energy storage system (LS-BESS) to prevent LT voltage instability in a power system integrated with LS-PVPs. For this purpose, a new coupling between optimization and dynamic simulations is proposed to treat the problem as an objective function, which uses the particle swarm optimization (PSO) algorithm. This objective function is used to minimize investment costs and voltage drops of the system by determining the optimal number, location, and capacity of LS-BESSs. Furthermore, the effects of local voltage control modes and power priority settings of LS-BESSs are investigated. Besides, effectiveness of the proposed approach is validated through several scenarios using time-domain simulations of a more realistic system, namely the Nordic system. According to the results, upon using the proposed approach, negative effects of LS-PVPs on voltage stability and costs required for expanding and reinforcing the transmission network decreased. In addition, voltage collapse was prevented, investment costs of LS-BESSs were minimized, and costs required for reactive power compensation devices and communication between controllers decreased.