永磁交流伺服电动机弱磁控制性能分析(下)

Flux-Weakening Control of Permanent Magnet AC Servo Motor

本文从弱磁控制的基本特性出发,指出永磁交流伺服电机弱磁控制能改善电机及驱动系统的性能;根据弱磁控制的基本原理,针对凸极率不同的永磁转子结构,对永磁交流伺服电机电压极限曲线中心在电流极限圆外、圆上和圆内3种情况,全面深入分析了该类电机的弱磁控制特性;推导出了从零转速经弱磁基速至弱磁最高转速的全范围机械与功率的变化规律,绘制了特性曲线,得到了最大功率和最大转矩点以及最大可能的弱磁范围。根据分析结果,分别讨论电机的凸极率,最大电流与励磁电流之比,电机导磁磁路与电机结构,以及直轴电感等各因素对电机弱磁性能的影响,并简要分析弱磁时电机损耗的特征。

This paper starting from the basic properties of flux-weakening, pointed out that the flux-weakening control of permanent magnet AC servo motor can improve the performance of motor and drive system. Aiming at the permanent magnetic rotor structure with different salient poles, three cases of the permanent magnet AC servo motor voltage limit curve center in the current limit circle, the circle and the circle were analyzed in detail, on the basic principle of flux-weakening control. Derived the change law of the whole range of mechanical and power from the flux-weakening base speed to the maximum flux-weakening speed, and the characteristic curve was drawn, the maximum power and torque point and the maximum possible weak magnetic range were obtained. According to the analysis results, the influence of the salient pole rate, the maximum current and the excitation current, the magnetic circuit and the motor structure of the motor, the direct axis inductance and other factors on the motor weak magnetic performance were discussed respectively, and the characteristics of the motor loss in flux-weakening were briefly analyzed.