一种电动汽车用异步电机弱磁控制方法

A Novel Field-weakening Control of Induction Motor for Electric Vehicles

为实现电动汽车用异步电机的宽范围调速,提出一种新的电压轨迹弱磁控制方法。该方法无需查表,可降低对电机参数的敏感性。此外,电压轨迹可以达到空间矢量调制的六边形,有效提高直流侧电压利用率。该方法以逆变器调制波的开关周期与导通时间之差控制定子电流励磁分量。当导通时间小于开关周期时为恒转矩控制,相反即为弱磁控制。同时,对电压和电流限制可以实现恒转矩区向弱磁区的平稳过渡。系统仿真与实验结果均验证了该方法的有效性。

In order to implement the speed regulation in a wide range, a new voltage trajectory field-weakening control of induction motor for electric vehicles was proposed. The presented method does not require a lookup table and reduces the parameter sensitivity. Moreover, the voltage trajectory can reach hexagon of the space vector modulate such that the DC- link voltage utilization can be extended. The differences between the switching period and the summation of active switching times for inverter pulse width modulation control the flux component of stator current. As the active switching times is less than its switching period, constant torque is retained. In contrast the field-weakening control is considered. Meanwhile,smooth and automatic transition from constant torque region to field- weakening region can be achieved by the voltage and current constraints. Experimental and simulation results will be presented to fully support the claims.