适用于电流型变流器的基于分类算法的快速空间矢量过调制策略

A Fast Space Vector Overmodulation Strategy Based on Classification Technique for Current Source Converters

提出了一种适用于电流型变流器(Current Source Converters,CSC)的基于分类算法的快速空间矢量过调制策略。由于引入分类算法,该空间矢量调制策略只需简单计算即可确定开关状态及其作用时间。同时本文提出的过调制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,本文也对逆变器输出电流的谐波畸变率进行了详尽分析,将此过调制策略应用于基于电流型变流器的不间断电源(Uninterruptible Power Supplies,UPS)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 based on classification technique for space vector pulse width modulation （PWM） suitable for current source converters （CSC） is proposed in this paper. Due to using the classification algorithm, the space vector modulation does not require much calculation to guarantee exact positioning of the switching instants and their dwelling time. The proposed overrnodulation strategy divides the overmodulation range into two modes, and allows smooth transitions through the entire operating area, from the linear range up to six-step operation, and keep the linear relationship between the output current and the modulation index. In addition, harmonic components 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.