有轨电车永磁牵引系统PWM调制策略研究

Research on PWM Modulation Strategy of Permanent Magnet Traction System for Tramcar

有轨电车永磁牵引系统具有功率大、功率器件开关频率低的特点,为解决其不能全程异步调制、低次谐波大的问题,研究了一种基于中间60°同步调制的多模式PWM调制策略。有轨电车永磁牵引系统在应用矢量控制的基础上,通过采用多模式PWM调制策略,实现了全速度范围内从异步SPWM调制、同步SPWM调制、中间60°同步调制和方波调制之间的平滑过渡,输出电流畸变率小于18%,有效降低了电流谐波。现场实验结果表明,该方法具有良好的实用性和有效性。

Permanent magnet traction system for tramcar has the characteristics of high power and low switching frequency. In order to solve the larger low-order harmonic and the problem that asynchronous modulation are not used in the full speed range, a multi-mode PWM modulation strategy based on central 60° synchronous modulation were adopted. Based on the vector vontrol, the permanent magnet traction system for tramcar has realized smooth transition of asynchronous SPWM modulation, synchronous SPWM modulation, central 60° synchronous modulation and square wave modulation in the full speed range by adopting a multi-mode PWM modulation strategy. The current distortion rate was less than 18%, effectively reducing the current harmonics. Field experiments showed that the multi-mode PWM modulation method has good practicability and effectiveness.