基于非线性拟合单位电流最优输出功率的永磁同步电机位置估计误差补偿策略

Nonlinear fitting of maximum output power per current for position error compensation in sensorless control of a permanent magnet synchronous motor

针对永磁同步电机(permanent magnet synchronous motor, PMSM)参数变化影响转子位置估计精度问题,提出了一种基于单位电流最优功率输出的位置估计误差非线性补偿策略。首先,分析了电机参数误差特别是电感误差对位置估计精度的影响,建立了位置估计误差与单位电流输出功率的关联模型,推导出电感误差与最优输出功率的关系模型。然后,结合功率模型构建了基于多项式的电感误差非线性模型,利用少量测试点拟合该多项式模型,即可辨识电感误差用于准确补偿位置估计误差。所提方法实现简单,不依赖电机参数,能有效克服噪声干扰。最后,仿真与实验结果验证了提出补偿策略的有效性。

There is a problem that rotor position estimation accuracy is affected by the parameter variation of a permanent magnet synchronous motor(PMSM).Thus a nonlinear compensation strategy for position estimation error based on the maximum output power per current is proposed.First,the influence of motor parameter error,especially inductance error,on the precision of position estimation is analyzed.The correlation model between position estimation error and output power per unit current is established,and the relationship model between inductance error and optimal output power is derived.Then,combined with the power model,a polynomial inductance error nonlinear model is constructed.By fitting the polynomial model with a few test points,the error inductors can be identified and used to accurately compensate for the position estimation errors.The proposed method is simple,independent of motor parameters,and can effectively overcome noise interference.Finally,simulation and experimental results verify the effectiveness of the proposed compensation strategy.This work is supported by the National Natural Science Foundation of China(No.62103455 and No.52105079).