永磁同步电机直接转矩控制系统开关表分析

Analysis of the Switching Table of the PMSM DTC System

使用三相和两相混合连接,两电平电压源逆变器可以生成12个不同相角的电压矢量,从而为永磁同步电机直接转矩控制系统优化开关表提供更多的电压矢量选择。提出了一种基于12电压矢量优化开关表,并实验对比了永磁同步直接转矩控制系统在传统开关表和基于12电压矢量优化开关表控制下的性能。实验结果表明,优化开关表能够减小不合理转矩脉动,但两相导通方式也带来了换相转矩脉动,恶化了系统控制性能。

A two-level voltage source inverter （VSI） can generate 12 voltage vectors with different angles using three-phase and two-phase connection which can provide more voltage vector selection to the optimal switching table of PMSM DTC. And a modified switching table based on effects of these 12 voltage vectors on permanent magnet synchronous motor （PMSM） direct torque control （DTC） system was proposed. Experi- mental results of PMSM DTC system under the control of the conventional switching table and the proposed switching table were given. Experimental results show the proposed switching table can suppress unreasonable torque ripple, but the use of two-phase connection will bring commutation torque ripple which degrades the control performance.