无刷直流电机双模糊直接转矩控制系统的研究

摘要

Aiming at issue that the direct torque control of brushless DC motor had large torque ripple and poor self-adaptability of traditional PID speed loop, the speed loop and torque controller of the direct torque control system were studied, and the direct torque control strategy was summarized, and a double fuzzy control strategy was proposed. In the speed loop, the basic PID controller was replaced by the fuzzy a-daptive PID controller, and self-tuning of the PID parameters was implemented. In the torque control loop, on the basis of the torque hystere-sis controller,the torque deviation and the rate of change of the torque deviation were fuzzified,the action time of the non-zero vector and the zero vector was controlled by fuzzy control, and eliminates the hysteresis width selection torque ripple effect, so that further reduce the torque ripple. The results indicate that compares with the traditional direct torque control system of brushless DC motor, the direct torque control system with double fuzzy control strategy can further improve the self-adaptability of rotation speed and the anti-disturbance ability of load torque,which greatly improves the control performance of the system.%针对无刷直流电机直接转矩控制存在传统PID速度环自适应较差和相对较大的转矩脉动等问题,对直接转矩控制系统的转矩观测等方面进行了研究,对直接转矩控制策略进行了归纳,提出了一种双模糊控制策略.在转速闭环中,以模糊自适应PID代替普通的PID控制,实现了PID参数的自适应整定.在转矩控制环中,在转矩滞环控制器的基础上,将转矩的偏差和转矩偏差的变化率模糊化,模糊控制非零矢量和零矢量的作用时间,消除了容差宽度选择对转矩脉动的影响,使转矩脉动进一步减小.研究结果表明,相比普通的直接转矩控制系统,引入双模糊控制策略的直接转矩控制系统,可进一步地减小电磁转矩脉动和提高转速的自适应调节能力,显著地改善系统的控制性能.