基于空间矢量的同步磁阻电机直接转矩控制

针对传统直接转矩控制由于采用滞环比较器对磁链和转矩进行直接控制,导致磁链、转矩脉动较大和开关频率不固定等问题,对同步磁阻电机直接转矩控制进行了研究,开展了直接转矩控制的基本原理分析,根据同步磁阻电机的数学模型,提出了一种定子磁场定向下磁链和转矩双闭环PI控制结构的直接转矩控制方案,采用空间矢量调制策略,克服了传统直接转矩控制的缺点。利用Matlab/Simulink搭建了两种直接转矩控制方案的仿真模型,并利用基于d SPACE的实验平台对该方案的低速性能进行实验研究,研究结果表明:相较于传统的直接转矩控制,该方案能明显减小电机的转矩脉动并且能保持开关频率恒定,能使电机在低速范围内具有良好的动态性能,并且使得电机在低速范围内稳定运行,证明了该方案的可行性和有效性。

Direct torque control for synchronous reluctance motor based on space vector modulation

Aiming at the problems of large flux and torque ripples and variable switching frequency in conventional direct torque control (DTC) with a pair of hysteresis comparators to control motor stator flux and electromagnetic torque, the direct torque control of synchronous reluctance motor (SynRM) was studied. After the analysis of basic principle of DTC, a kind of direct torque control scheme of a double closed-loop flux and torque PI control under the stator field was presented according to the mathematical model of SynRM. The space vector modulation (SVM) was applied to the DTC. Matlab/Simulink simulation of two direct torque control schemes was established, and the low speed performance of SVM-DTC method was studied based on dSPACE experimental plat-form. The results indicate that the SVM-DTC method can dramatically decrease the flux and torque ripples with fixed switching fre-quency compared with the conventional DTC. In addition, the SVM-DTC method can make the motor have good dynamic performance in the low speed range and make the motor run smoothly in the low speed range, which proves the feasibility and effectiveness of the method.