一种抑制无刷直流电机转矩脉动的调制方法

A Modulation Method to Decrease Commutation Torque Ripple of Brushless DC Motors

针对无刷直流电机存在较严重的转矩脉动问题,提出在换相区采用三相绕组共同调制方法来减小换相转矩脉动;在导通区,采用滞环比较原理实现对电机转矩、磁链的跟踪控制,从而消除非换相转矩脉动。在电机转矩与输入能量之间建立联系,按照单周期控制思想,使系统能够准确控制输入能量,进而准确控制电机转矩。仿真和实验结果表明,相比于传统的控制方法,采用转矩脉动抑制方法,在换相区和导通区内的电流和电磁转矩波形都更平稳。并且当电机转速变化时,采用传统控制方法得到的电流和电磁转矩会产生波动;而采用脉动抑制方法时,电机转速变化对绕组电流的影响不大,电机能够相对稳定地输出电磁转矩,验证了文中理论分析的正确性和有效性。

Aimed at the problem that serious torque ripples exist in brushless DC motors （BLDCM）, this paper proposes a three-phase cooperative modulation to eliminate the commutation torque ripple. During non-commutation, the paper proposes a direct torque control to eliminate torque ripple by adopting hysteresis comparison to follow-up control torque and flux linkage of BLDCM. The paper establishes a relationship between motors torque and input power. The method based on one cycle control enables the system to control input power accurately, even more control torque of BLDCM correctly. The simulated and experimental results show that the method of torque ripple suppression of current and electromagnetic torque waveform is smooth for a motor in speed changes compared with the traditional control method whose current and electromagnetic torque can produce fluctuations. When the torque ripple suppression method is used, the influence of motor speed changes on the influence of winding current is small. Motor electromag- netic torque can relatively stably output. The validity and corrective of the theoretical analysis are verified.