双星型多电平铁路功率调节器及其控制方法

A Railway Power Conditioner and Its Control Method Based on Double Star Bridge Cells

电气化铁路向高速、大功率发展的同时,给牵引电网带来不容忽视的电能质量问题。为实现牵引电力系统三相电流的平衡,研究一种高压大容量的双星型多电平铁路功率调节器。该调节器采用模块化高压级联结构,由4个H桥链节及输出滤波电感组成,可直接挂接于27.5 kV电压等级,能用于多种类型牵引供电系统的功率调节,尤其适用于斯科特(Scott)同相供电牵引系统的功率转移和补偿。在分析该新型铁路功率调节装置拓扑结构、等效模型以及功率平衡的基础上,提出以调节器电压平衡为目标的分层控制策略,以保证系统的安全稳定运行。最后通过仿真和实验验证了所提补偿装置和控制方法的有效性。

With the development of the electrified railway in the direction of high-speed and high-power, the power quality of the electric traction grid becomes more and more serious. For the purpose of the three-phase current balance of electric traction grids, a double star bridge cells based railway power conditioner（DSBC-RPC） with the advantages of both high-voltage and large-capacity was studied. The DSBC-RPC was characterized by the modular and high voltage cascade structure, consisting of four H-Bridge links and corresponding output filter inductors, which could be directly connected to the voltage class of 27.5 k V. This conditioner could be used for different types of traction transformers, especially suited to the active power transfer of Scott transformer electric traction systems with a co-phase supply mode. Based on the analysis of the topology structure, the equivalent model and the energy balance of DSBC-RPC, the hierarchical control strategy was put forward aiming to balancing the sub-module capacitance voltage, which ensured the safety and stability of the system. Finally, the proposed structure and its control strategy effectiveness are verified by the simulations and experiments.