【摘要】 轨道交通牵引系统运行速度范围广,稳定性要求高,这就使得牵引系统应具备从异步调制到方波的平滑过渡能力,通常的解决方法是采用混合脉宽调制策略。目前,常用的混合脉宽调制策略有两种,一种是采用无载波调制连接异步调制和方波,另一种则采取同步过调制策略连接异步调制和方波。该文分析了这两种方法的优缺点,针对同步过调制策略,介绍了传统的异步过调制和同步过调制,结合传统方法的缺陷,该文提出了改进型同步SVPWM过调制策略。最后,通过仿真及实验,证明改进型同步空间矢量脉宽调制(SVPWM)过调制策略具有实现简单,过渡期转矩无脉动的优点。更多还原

【Abstract】 The rail transit traction system has a wide operating speed range and high stability requirements, which makes the traction system should have a smooth transition from asynchronous modulation to square wave. The usual solution is to adopt a hybrid pulse width modulation strategy. At present, there are two commonly used hybrid pulse width modulation strategies, one is to use a non-carrier modulation to connect asynchronous modulation and square wave, and the other is to adopt a synchronous overmodulation strategy to connect asynchronous modulation and square wave. In this paper, the advantages and disadvantages of these two methods are analyzed. For the synchronous overmodulation strategy, the traditional asynchronous overmodulation and synchronous overmodulation are introduced. Combined with the defects of the traditional method, this paper proposes an advanced synchronous space vector pulse width modulation(SVPWM) overmodulation strategy. Finally, through simulation and experiment, it is proved that the advanced synchronous SVPWM overmodulation strategy has the advantages of simple implementation and no ripple in the transition period.更多还原