感应电动机转子磁场定向下的弱磁控制算法

Field Weakening Algorithm of Induction Motor With Rotor Flux Oriented Control

电动汽车、数控机床等应用领域要求感应电动机具有宽范围的恒功率弱磁调速能力。提出一种感应电动机弱磁状态下电压和电流轨迹控制的新方法。在满足电机和驱动器最大电压和电流约束条件的前提下,该方法可实现全速度范围内的最大转矩输出。此方法不需要查表运算,对电机参数的依赖性较低。通过对SVPWM方法中得到的零电压矢量作用时间的积分,可得到d轴电流的给定值,从而实现最大转矩电流比(maximum torque per ampere,MTPA)控制区与弱磁区之间的平滑过渡。在5.5 kW系统上对所提弱磁方法进行仿真和实验验证,实验结果证实了该方法的可行性。

In many applications such as electrical vehicle and computer numerical control machine,induction motor（IM） needs large speed range operation with constant output power.A new current and voltage trajectories control scheme for the field weakening operation of induction motor drive was presented.The proposed scheme allows the motor to exploit the maximum torque capability in the whole speed range with the constraints of maximum voltage and current of the motor and inverter.In the proposed control algorithm the lookup table is not required for currents references obtaining,which reduces the dependence on the motor parameters.The smooth transition between maximum torque per ampere（MTPA） and field weakening regions is implemented according to the integration of the time of zero voltage vector in SVPWM method.The validity of the proposed field weakening technique is validated by computer simulations and experimental tests with a 5.5？kW induction motor drive system.