Constant DC-Capacitor Voltage-Control-Based Reactive Power Control Strategy of Three-Level NPC Inverter-Based STATCOM

摘要

This paper proposes a constant de-capacitor voltage-control (CDCVC)-based reactive power control strategy of a static synchronous compensator (STATCOM) with a three-level neutral-point-clamped (NPC) inverter, where the source-side harmonic currents are also compensated simultaneously. The CDCVC-based reactive power control strategy uses only a CDCVC, which is always used in grid-connected inverters, STAT-COMs, etc. Calculation blocks of fundamental active, reactive and harmonic components are not required. Thus, the authors propose a simplified strategy for the source-side reactive power control with the source-side harmonic currents compensations. The instantaneous power flowing into a STATCOM shows that using the CDCVC-based strategy achieves sinusoidal source-currents with controlled source-side reactive power compensating the harmonic currents on the source side. Simulation and experimental results demonstrate that sinusoidal source-currents are obtained with the CDCVC-based strategy controlling the reactive power on the source side.