Optimal placement of static compensators for multi-objective voltage stability enhancement of power systems

Static compensators (STATCOMs) are able to provide rapid and dynamic reactive power support within a power system for voltage stability enhancement. While most of previous research focuses on only an either static or dynamic (short-term) voltage stability criterion, this study proposes a multi-objective programming (MOP) model to simultaneously minimise (i) investment cost, (ii) unacceptable transient voltage performance, and (iii) proximity to steady-state voltage collapse. The model aims to find Pareto optimal solutions for flexible and multi-objective decision-making. To account for multiple contingencies and their probabilities, corresponding risk-based metrics are proposed based on respective voltage stability measures. Given the two different voltage stability criteria, a strategy based on Pareto frontier is designed to identify critical contingencies and candidate buses for STATCOM connection. Finally, to solve the MOP model, an improved decomposition-based multi-objective evolutionary algorithm is developed. The proposed model and algorithm are demonstrated on the New England 39-bus test system, and compared with state-of-the-art solution algorithms.