零阻变换器系统中开关单元的优化分布方法

零阻变换器系统(zero-resistance converter system，ZRCS)能将走行轨电流从虚拟回流地处转移至回流线缆， 进而从源头上治理城市轨道交通钢轨电位与杂散电流问题。作为 ZRCS 中影响虚拟回流地位置的关键部件之一， 开关单元的数量与分布会直接影响钢轨电位和杂散电流的分布。在实际列车运行过程中，牵引和制动工况下的列 车电流及相应钢轨电位远大于匀速工况；通过调整开关单元的分布，降低这部分的钢轨电位，可提高 ZRCS 的综 合治理效果。因此，在分析 ZRCS 中开关单元作用的基础上，提出其优化分布方法；通过对比不同开关单元分布 下的治理效果，得到较优方案。仿真结果表明：所提出的优化方法能进一步提高 ZRCS 的治理效果，具有可行性。

Optimal Distribution of a Switch Unit in a Zero-resistance Converter System

A zero-resistance converter system (ZRCS) transfers the rail current from the returning point to the return cable and mitigates the rail potential and stray current in the urban rail transit from the source. As one of the key devices, the switch unit (SU) influences the position of the returning equipoint in the ZRCS. The number and distribution of SUs directly affect the distribution of the rail potential and stray current. During actual train operation, the train current under traction and braking conditions is much larger than that under constant speed conditions, resulting in a correspondingly larger rail potential. By changing the SUs distribution, the rail potential of this part can be reduced, and the comprehensive mitigation performance of the ZRCS can be improved. Therefore, a method for optimizing SU distribution based on an analysis of the role of the SU is proposed. The optimal SU distribution was obtained by comparing the mitigation performance under different SUs distributions. The simulation results indicate that the proposed optimization method can improve the mitigation performance of the ZRCS.