基于预测占空比的无刷直流电机转矩脉动抑制

Torque Ripple Suppression of BLDC Motor Based on Predicting Duty Cycle

无刷直流电机通常采用两相导通六步控制的驱动方案,但由于存在周期性的转矩脉动,限制了在伺服系统等高精度场合的应用。本文提出了一种预测占空比的转矩脉动抑制方案。结合电机不同运行状态下的数学分析,通过预测PWM工作状态下的占空比,可以在全速域下实现非换相期间导通相相电流恒定、换相期间非换相相电流恒定,从而有效抑制转矩脉动。仿真结果验证了该理论的正确性,在稳态和动态情况下都可以有效抑制转矩脉动。

Brushless DC(BLDC) motor usually adopts the control method of six-step with two-phase conduction, but the presence of periodic torque ripple limits its application in high-precision areas like servo systems. A torque ripple suppression method based on predicting the duty cycle was proposed. On basis of mathematical analysis of BLDC under different operating states, and by predicting the voltage duty cycle in pulse width modulation(PWM) mode, the following effects could achieved in the full speed region: constant conducted phase current during non-commutation period and constant non-commutation phase current during commutation. Thus torque ripple minimization could effectively guaranteed. The simulation results proved the correctness of the method, and great torque ripple suppression can be realized under both steady and dynamic conditions.