Capacitor voltage balance performance comparison of MMC-STATCOM using NLC and PS-PWM strategies during negative sequence current injection

摘要

This paper addresses the modular multilevel converter applied as a static synchronous compensator. The main objective of this work is to compare the converter performance considering two different submodule capacitor voltage balancing strategies: nearest level control and phase-shifted pulse width modulation, during positive and negative sequence current injection. Results of a 15 MVA MMC STATCOM show that the nearest level control strategy has lower average switching frequency compared to the phase-shifted pulse width modulation strategy, considering comparable submodule capacitance voltage ripple.