Optimal Pulse Width Modulated STATCOMs in Photovoltaic Power Plants

According to the requirements of grid connection, grid-connected PV system with static synchronous compensators (STATCOMs) can compensate reactive power and keep grid-connected voltage steady. This paper presents a particle swarm optimization method to optimize the harmonic output of a three-level voltage source converter (VSC) STATCOM using pulse width modulation (PWM) scheme. Two modulation strategies, the selective harmonics elimination technique (SHE) and total harmonic current distortion (THD) minimization, are evaluated and compared. It is observed that the better quality of the input current is generated by THD minimization modulation. The simulation and experimental studies have also verified that the proposed method can reduce the harmonic distortion effectively and obtain high-quality waveforms.