Research on Topology and Control Strategy of Railway Power Regulator Based on MMC

摘要

Railway static power conditioner(RPC) can effectively overcome the shortcomings of traditional conditioner which has poor negative sequence and harmonic compensation effect, it provides a new way to control the power quality of high-speed railway. However, the traditional two-level RPC device occupies a large area, and it will also encounter direct current bias magnetic problem, which distorts the voltage of the system and the excitation current distorts to form peak waves. At this time, the harmonic content increases dramatically and the reactive power loss of the transformer increases. In this paper, the MMC topology and RPC structure are combined to form the MMC-RPC topology, which is directly connected to the traction power supply arm, eliminating such deficiencies as large floor area, large loss and distortion of output current waveform of the booster transformer. At the same time, this paper also studied the capacitor voltage equalization control and circulation suppression strategy of MMC-RPC topology. Finally, the MMC-RPC topology simulation model is built to verify the feasibility and effectiveness of the topology structure and control strategy.