交流永磁同步电动机弱磁控制

Field- weakening Control for Permanent Magnet AC Synchronous Motors

提出了一种模拟式永磁同步电动机的弱磁控制方式，建立了一个函数发生器，在实际速度高达某一数值之后，函数发生器就根据某一规律送出弱磁分量电流；由速度调节器根据指令速度与实际速度之差产生转矩电流分量．旋转变压器作磁场定向的位置传感器，提供ｓｉｎθ和ｃｏｓθ信号实现和的坐标变换。为了增强弱磁效果，电机转子由永磁部分和各向异性的磁阻部分组成，实验结果表明．加Ｉｄ进行弱磁控制，永磁同步电动机速度控制范围能拓宽一倍以上，且恒功率控制效果较好。

This paper presents an analog type of field-weakening ccntrol for permanent magnetsynchronous motors。A demagnetizing component of stator current is provided by a func-tion generator according to a given rule when the actual motor speed exceeds the base one。The difference between the reference speed and the actual speed serves as teh input to aspeed controller and the output of which is the current,the torque producing the compo-nent of stator current.The components and are transformed into a stationary referenceframe by the application of sinθ and cosθ signals provided by a position sensing resolver forfield-oriented control.The rotor of the permanent magnet synchronous motor is composed ofapermanent magnet section and a reluctance section to improve the field-weakening effect。Experimental results show that the speed range of the motor can be extended to twice thebase speed and has better system performance in constant power operation。