无刷直流电机改进型直接转矩控制研究

Improved Direct Torque Control in Brushless DC Motor Drives

研究了120°导通方式下的无刷直流电机直接转矩控制策略。通过分析了无刷直流电机转矩特性知道,只要保持定子磁链幅值恒定并控制其旋转速度就可使电机获得快速转矩动态响应性能。对120°导通方式下的无刷直流电机控制,定子磁链可近似认为保持不变。然而,对磁链幅值的控制将会改变电机绕组的固定导通方式,仅通过控制定子磁链旋转速度就可以实现电机的有效控制。在此基础上提出了一种新颖的无刷直流电机直接转矩控制数字实现方案,所提策略去除了磁链控制,其中分别提出了两套不同的逆变器开关表。仿真研究结果验证了新策略的可行性和有效性。

An investigation of an inproved direct torque control（DTC）for brushless DC motor（BLDC）drives in120 elec. degree conduction mode was described. The performance of torque in BLDC-DTC system was analyzed.Keeping the amplitude of stator flux linkage constant and controlling its rotary speed are keys to obtain a fast torqueresponse. The part of controlling the amplitude of stator flux linkage was removed in the system for its ineffectiveness,then a novel DTC strategy which include two different switching tables and two estimators for flux linkage and torquewas proposed. The simulation results verify the proposed scheme and demonstrate that it has a much better steady stateperformance while keeping a good dynamic performance compared with the traditional PWM method