直接转矩控制系统中减小转矩脉动方案的比较

采用离散空间矢量调制(DSVM)和转矩预测技术减小感应电机直接转矩控制系统(DTC)低速时的转矩脉动,为了系统实现时编程简单,对DSVM的开关表进行了优化,将每个采样周期分为3个相等的时间段,每个时间段中作用一个电压矢量,采用单一非零电压矢量与零电压矢量的组合来代替非零电压矢量与非零电压矢量的组合,简化了开关表,降低了开关频率,保证了低速时的带载能力.在此基础上将DSVM与转矩预测进行了实验对比.实验结果表明:与转矩预测相比,开关表优化后的DSVM在减小低速时的转矩脉动,改善电流和磁链波形方面取得了更好的控制效果,且保持了转矩动态响应快的优点.

Comparison between two kinds of reducing torque ripple of based on direct torque control

The study of reducing torque ripple of induction motor direct torque control(DTC) in the low-speed was conducted by using discrete space vector modulation(DSVM) and torque prediction technology,and switching table of DSVM has been optimized.Each sampling period was divided into three equal time intervals,and a voltage vector was applied at each interval,that is,a single non-zero voltage vector and zero-voltage vector replaced the combination of non-zero voltage vector and non-zero voltage vector,which simplified the switch table,reduced the switching frequency and ensured a low-speed carrying capacity.On the basis of that,the experimental results were contrasted.The results showed that compared with the torque prediction,optimized DSVM makes control effect in reducing the low-speed torque ripple better,improves the current and flux wave,and maintains a dynamic torque of the advantages of fast response.