滞环容差自适应算法的直接转矩控制研究

传统感应电机直接转矩控制(DTC)系统的滞环控制器为Bang-Bang控制, 其滞环容差保持不变, 因此低速下被调节的磁链和转矩具有较大脉动. 为改善转矩和磁链响应, 在传统滞环比较器基础上, 提出了一种滞环容差自适应调节控制方法, 通过对转矩或磁链误差的当前采样值和历史采样值以及滞环比较历史输出值的综合比较, 得到当前滞环输出控制信号, 并充分利用零电压矢量和反向电压矢量, 达到满意控制效果. 仿真结果表明该算法不仅能有效降低定子磁链和转矩脉动, 也能够有效降低开关频率, 提高了逆变器效率.

Research on Hysteresis Bandwidth Adaptive Algorithms in DTC Systems

The bandwidth of the conventional hysteresis controller for the Bang-Bang control is constant in the direct torque control (DTC) systems of induction motors, thus the ripple of the tuned flux and torque is stronger in low speed. In order to improve the torque and flux response, a hysteresis bandwidth adaptive control algorithm is proposed on the basis of conventional hysteresis comparator. By the comprehensive comparison of the current sample value, historical sample value of the torque error or flux linkage error as well as the historical output values of the hysteresis comparator, the current hysteresis control signal is achieved, and the zero voltage vector and the backward voltage vector are used fully to achieve satisfactory control effect. The simulation result shows that the new hysteresis control algorithm can not only effectively reduce the stator flux and torque ripple, but also can effectively reduce the switching frequency, and improve the efficiency of the inverter.