在弱磁调速下,异步电动机变频系统电磁转矩控制的非线性特性、以及系统最大输出电压和电流的限制,使得转矩和功率控制比较复杂。该文分析了弱磁调速区间内最大电磁转矩与电动机参数、系统电压电流约束之间的关系,给出了改善控制性能所需的系统最大电磁转矩和最大功率随定子同步频率以及最大电流约束变化的定量关系。实物实验验证了这些特性。
In the flux-weakening operation region of an inverter-induction motor drive,the control of electromagnetic torque(EMT) and power becomes complicated,due to the nonlinear characteristic of the EMT and output voltage/current constraints of the drive.For the control performance improvement,this paper describes the function of the maximum EMT about the motor parameters and the voltage/current constraints,and presents the algorithms of the maximum EMT and the electromotive power along with the variation of stator frequency as well as the current limitations.Test results verify the algorithms.