适用于电流型变流器的空间矢量过调制策略

提出一种适用于电流型变流器(current source conver- ters, CSC)的空间矢量过调制策略。该方法根据调制比将整个过调制区域分为两部分，能实现变流器从线性区域到六脉波状态的平滑过渡，并且保证输出电流和调制比之间成线性关系。另外，该文也对逆变器输出电流的谐波畸变率和低次谐波含量进行了详尽分析，将此过调制策略应用于基于电流型变流器的不间断电源上，系统能够获得更快的动态响应和更高的输出功率，并通过仿真试验得以验证。

AN OVERMODULATION STRATEGY FOR SPACE VECTOR PWM CURRENT SOURCE CONVERTERS

An overmodulation algorithm for space vector pulse width modulation (PWM) suitable for current source converters (CSC) is proposed. The proposed algorithm divides the overmodulation range into two parts, and allows smooth transitions through the entire operating area, from the linear range up to six-step operation, and keeps the linear relationship between the output current and the modulation index. In addition, the total harmonic distortion and the low-order harmonics of the output current are analyzed. When this technique is applied to the CSC-based uninterruptible power supplies (UPS), quicker dynamic response and higher output power are obtained, which are verified through simulation results.