永磁无刷直流电机转矩波动的自抗扰控制

Torque Ripple Reduction of PM Brushless DC Motors Based on Auto-disturbances-rejection Controller

自抗扰控制器(ADRC)是在继承经典PID不依赖于对象模型优点的基础上,通过改进经典PID固有缺陷而形成的新型控制器,性能优良且算法简单。在分析永磁无刷直流电机转矩波动研究现状的基础上,根据其自身特点以及自抗扰控制器的设计原则,提出了基于自抗扰控制器的永磁无刷直流电机转矩波动抑制方法。将电机等效为由2个非线性系统构成的串联对象,设计了2个一阶自抗扰控制器实现对电机的内外环控制,即外环控制转速并给出内环转矩参照值,内环控制转矩以抑制转矩波动,其实质是改善馈电电流波形。内环转矩子系统采用3个相同的扩张状态观测器(ESO)对三相转矩分别进行观测,进而得到电磁转矩估计值及转矩子系统的实时作用值,据此构造以逆变器直流侧电压为控制输入的转矩子系统一阶自抗扰控制器。实验结果表明,该控制方案不仅能够明显抑制电机运行中的转矩波动,而且电机具有良好的动态响应性能,控制系统具有较强的适应性和鲁棒性。

Torque ripple reduction of PM brushless DC motors is considered, and a new approach based on autodisturbances-rejection controUer（ADRC） is proposed subsequently. Inheriting the merit of independent of system model and overcoming the shortcomings of classic PID controller, ADRC possesses good performance with relatively simple algorithm. Starting from the characteristics of the PM brushless DC motors and the principles of the design of ADRC, the motor model is transferred into a series-connection object. Then two one-order ADRCs are constructed to carry out closed-loop control. One ADRC, which represents the outer loop, controls the rotor speed and specifies the reference torque for the inner loop; while the other manipulates the torque to minimize torque ripple, which actually improves the waveform of the feeding current. The inner loop of torque sub-system adopts three uniform extended state observers（ESO） to obtain the estimation torque and the real operational value of the torque sub-system. A one-order ADRC with the DC value as the contrOl input, is then configured. The experiment results show that the scheme ensures prominent reduction of torque ripple when the motor is in operation; moreover, the motor produces＇ good dynamic performance, good robustness and adaptability.