基于实时延拓法的PWM BDCM转矩消谐控制算法

首先提出电压型PWM逆变器供电的正弦波永磁无刷直流电动机谐波转矩模型，其模型是一组以逆变器开关角为变量的非线性方程。应用传统的牛顿一拉夫逊法计算开关角时，收敛速度慢、收敛域小，无法达到实时消除谐波转矩的要求。为此，根据正弦波永磁无刷直流电动机谐波转矩模型的特点，提出实时延拓法转矩消谐的控制算法。该算法具有收敛速度快、收敛域大的显著优点，从而能够通过单片机实现谐波传矩的实时消除控制。

Harmonic elimination for the torque of PWM BDCM based on real-time homotopy algorithm

In this paper, a mathematical torque model of BDCM (Brushless DC Motor) fed by voltage source PWM inverter is developed. The equations of the model are simultaneous nonlinear equations with switching angles, which can be solved with Newton Raphson method. But the speed of the traditional Newton Raphson method is slow for its limited convergence margin and cannot meet the demand of real-time harmonic torque elimination. According to the characteristic of the sine wave permanent magnet BDCM, a control technique of real-time harmonic torque elimination with homotopy algorithm is presented. Calculation shows that the technique has the large convergence margin and quick convergence rate.