双三相感应电机新型空间矢量脉宽调制策略研究

A Novel SVPWM Scheme for Dual Three-phase Induction Motor

电压源型逆变器驱动双三相感应电机时共有64种开关状态,电压调制算法复杂。基于分类算法提出了一种十二边形空间矢量脉冲宽度调制(space vector pulse widthmodulation,SVPWM)策略。与其他研究相比,该新型调制策略可有效缩短算法处理时间,扩展调制区域。算法对输入的电压进行分类,获取最大和次大的中间变量,从而判断参考电压矢量所在扇区;对中间变量进行线性组合可求得基本矢量作用时间,从而缩短算法处理时间。该算法通过将调制区域分为3段,可实现线性调制区域向过调制区域的平滑过渡。仿真和实验结果表明,线性调制区可抑制定子电流谐波;过调制区可补偿十二边形外电压矢量损失。

A voltage source inverter has 64 switching modes to feed dual three-phase induction motor drive systems,and the voltage space vector modulation algorithm is complicated.This paper presented a dodecagon space vector pulse width modulation（SVPWM） strategy using classification algorithm.It is different from previous researches,the new modulation algorithm can reduce the processing time and extend the modulation range.The algorithm obtains the largest and the second largest intermediate variables which determine the sector of the reference voltage via the classification of the input voltage vectors.The dwelling time of the basic vectors is obtained by a linear combination of the intermediate variables to reduce the computational time.The proposed technique allows smooth transition from a linear modulation region to an over modulation region by dividing the modulation region into three sections.The simulation and experiment show that the linear modulation can suppress the stator current harmonics and the over modulation can effectively compensate the dodecagon external voltage vector loss.