The start control strategy design of Unified Power Quality Conditioner based on modular multilevel converter

摘要

This paper proposes a new modular multilevel converter based unified power quality controller (MMC-UPQC). As one of the key technologies of MMC-UPQC, the start strategy is discussed and combined with the establishment of the DC side capacitance voltage. In this paper, the main circuit of MMC-UPQC and the operating states of MMC sub-modules (SMs) are described in detail. Two start control strategies are put forward and compared. The detection and control algorithm of UPQC is based on d-q coordinate transformation method. PSCAD/EMTDC simulation results and prototype experiment results are discussed to support the proposed start control strategies and verify the application of MMC in UPQC.