Optimal Sizing and Placement of ES-STATCOM for Voltage and Frequency Stability Under Steady-State and Dynamic Conditions in Renewable Power Systems

Abstract

This paper proposes an optimal sizing and placement method for an energy storage system combined with a static synchronous compensator (ES-STATCOM) to address stability issues due to reduced inertia and reactive power compensation in renewable energy (RE)-integrated power systems. The proposed method minimizes a multi-objective function considering voltage profile, frequency deviation, rate of change of frequency (RoCoF), and ES-STATCOM investment costs. It incorporates voltage and frequency stability under both steady-state and dynamic conditions. Using voltage and frequency control models, the artificial bee colony (ABC) algorithm optimizes ES-STATCOM sizing and placement. The proposed method was validated on a modified IEEE 14-bus system, showing a 52.22% improvement in voltage sensitivity compared to a synchronous generator (SG) system and 65.81% over a RE-integrated system. During a fault, the minimum frequency was 59.93 Hz with a RoCoF of -0.07 Hz, outperforming both SG and RE systems. The proposed method ensures voltage and frequency stability with ES-STATCOM and effectively mitigates voltage and inertia reduction issues in RE-integrated systems, offering more flexible and faster control than SG-based systems.