中文摘要：

为解决高速铁路牵引供电系统存在的以负序为主的电能质量问题和过分相问题,提出了一种基于模块化和背靠背结构功率变换器的同相贯通供电方案,在电网侧采用级联H桥链式拓扑,易于电压和容量的扩展;在牵引侧采用并联多重化拓扑,结合单相变压器串联输出,适应了AT供电方式的要求;采用功率模块动态旁路和恢复技术,保证了供电可靠性;通过优化变换器控制策略,实现了功率双向流动和平衡变换,抑制了直流侧电压脉动引起的谐波畸变。仿真结果表明,上述拓扑的可行性和控制策略的正确性。

英文摘要：

In order to solve the power quality problems largely caused by negative sequence and the problem of electric phase existing in the traction power supply system of high-speed railway,a new co-phase continuous traction power system based on back to back and modular power converter was proposed.Cascade H-bridge chain topology was used in the grid side of power converter,which was helpful to the expansion of voltage and capacity.Parallel multi-module topology was used in the traction side of power converter,combined with singlephase transformer output in series,which is suitable for AT traction power supply mode.The reliability of power supply was improved by power module dynamic bypass and recovery technologies.The optimization of inverter control strategy realized the bidirectional power flow and balance transformation and suppressedthe harmonic distortion caused by the DC side voltage fluctuation.The simulation results proved the feasibility of the topology and the correctness of the control strategy.