一种异步电机定子磁链弱磁控制方法

本文提出了一种电动汽车用异步电机的定子磁链弱磁控制方法,通过引入定子参考电压与逆变器能提供的电压值的比较,确定电机的运行区域,进而确定能够输出最大转矩的励磁电流,再结合给定转矩求出定子磁链参考值。本方法采用定子参考电压与母线电压对应值的比较,仅需简单计算即能实现恒转矩、恒功率、降功率区域的平滑过渡。在逆变器和电机的电压、电流能力一定时,能够输出最大转矩。无需转子磁链定向,适用于定子磁链控制的场合。通过动态调整转矩给定限制值可保证电机稳态运行不过流。仿真和实验结果证明了本方法的有效性。

Stator flux weaken method for the induction motor

A method of stator flux weakening for the induction motor used in EVs is proposed.The determination of the operation region of the motor is firstly decided depending on the voltage of the DC bus supplied by the inverter and the stator voltage reference.The optimal exciting current can then be obtained which can output the maximum torque.Then the stator flux reference of considering the torque reference can be achieved.It does not need rotor field orientation and is suitable for the schemes in which the stator flux is controlled.This method can output the maximum torque under the voltage and current capacity of the converter and motor.The stator voltage reference is used to compare with the corresponding limited voltage,then different operation regions of the motor can be judged.The calculation is simple and the transition between different regions is smooth.The dynamic given torque limit can make the motor to avoid over current in steady state.The effectiveness of the proposed method is verified by the simulation and experimental results.