自适应改进模糊调节电压矢量占空比永磁同步电机直接转矩控制

设计了模糊调节电压矢量占空比永磁同步电机(PMSM)直接转矩控制(DTC)，采用开关表选择电压矢量，采用模糊控制器确定电压矢量占空比。仿真结果表明，与传统DTC相比，可有效抑制磁链和转矩脉动，但也存在转矩较大时开关表控制失效引起转矩脉动的问题。针对开关表控制失效问题，提出了采用电压矢量选择策略取代开关表来选择电压矢量的改进控制策略。仿真结果表明：改进控制策略可有效抑制因开关表失效引起的转矩脉动，但动态性能较差。因此，进一步提出采用开关表与模糊调节电压矢量占空比的自适应切换控制。动态下，系统采用开关表控制；稳态下，系统采用改进模糊调节电压矢量占空比控制。仿真结果表明，自适应改进模糊调节电压矢量占空比控制可在保证良好稳态性能的基础上提升动态性能。

Adaptive Improved Direct Torque Control of Permanent Magnet Synchronous Motor Using Fuzzy Control to Adjust Duty Ratio of Voltage Vector

Permanent magnet synchronous motor (PMSM) direct torque control (DTC) system using fuzzy control to adjust duty ratio of voltage vector is proposed. The applying voltage vector is determined by switching table and the duty ratio of voltage vector is adjusted by fuzzy controller. Simulation results show that, compared with conventional DTC, the proposed fuzzy control system can suppress stator flux and torque ripples. But in the condition of large torque, there will be the torque ripple resulting from the failure of switching table. Aiming at this problem, an improved vector selection control strategy eliminating the switching table is put forward. This control strategy can suppress torque ripple, but its dynamic response is poor. Therefore, an adaptive control strategy is proposed, which uses switching table at the dynamic state and the improved vector selection control at the steady state. Simulation results show that the adaptive control strategy can improve the dynamic response and maintain the steady state performance of the system.