Volt-Var Optimization Using Differential Evolution

Abstract

This paper proposes a differential evolution-based optimal power flow (OPF) for reactive power dispatch (Volt-Var) in power system planning and operational studies. The problem is formulated as a mixed-integer non-linear optimization problem, taking into account both continuous and discrete control variables. The proposed method determines control variable settings such as generator voltage magnitudes, tap positions, and the number of shunt capacitors to be switched for real power loss minimization in the transmission system using a differential evolution (DE) algorithm with efficient constraint handling. The proposed methodology is tested on standard test systems such as IEEE 14-, IEEE 30-, and IEEE 57-bus systems, and the performance is compared with the genetic algorithm (GA) and interior point method (IPM). It was observed that the DE-based method is more robust and faster compared to the GA.

Keywords:

• OPF
• loss minimization
• DE
• GA
• penalty coefficients

Notes

^a Discrete variables are adjusted to nearest possible value.