地铁车辆逆变器回流电流谐波的理论推导

Theoretical Deduction of Return Current Harmonics in Inverters of Subway Vehicles

论述在直流供电的地铁系统中,逆变器的回流电流与信号电流都在回流轨中传输,回流电流中的谐波含量势必会对信号电流的传输造成影响。介绍以往在现场测试中对这种影响所进行的评估分析,认为相对于干扰因素较多的现场实测来说,对回流电流谐波的含量进行理论推导更具有普遍意义及可信性。为给谐波对信号的干扰研究提供理论帮助,采用开关函数原理,推导逆变器回流电流的数学表达,并通过仿真验证了数学推导的正确性。

Considering the fact that the return current and the signaling current are all transported through the rail of return current, the harmonics of the return current may interfere with the signaling current. Some authors use experimental study to investigate the indices of the compatibility between the return current and signaling current while theoretical investigation is more preferable. In this paper, switching function concept is adopted to deduct the mathematical expression of the return current in the inverter so as to provide theoretic asistance to study the interference of the harmonics with the signaling current. The proposed method has been verified by simulation and experiment results.