实现感应电机宽范围最大转矩控制的电流优化策略

针对广泛应用于数控机床主轴驱动系统中的交流感应电机,提出了一种新的宽范围运行的电流优化控制策略。根据感应电机在不同速段的转矩特性,充分考虑逆变器的输出电压限制、电机本体的电流约束条件及最大转差频率限制,以输出最大转矩为目标,得出了全速范围内的最优电流控制轨迹和感应电机宽范围转矩输出最大化的电流优化分配指导原则。在此基础上,设计了一种工程实现算法,依据电机实际运行的状态变量实现恒转矩区、恒功率区与恒电压区的快速平滑过渡,完成了对最优电流控制轨迹的逼近。实验结果证明了提出方法的有效性,可以实现感应电机宽范围运行的最大转矩输出,并且使系统具有较快的动态响应性能。

Implementation of Current Optimizing Strategy for Maximum Torque Control of Induction Machines Over a Wide Speed Range

This paper proposed a novel current control strategy that ensures maximum torque capability over the whole speed range for induction machines which widely used in industry applications,especially in spindle drive systems of machine tool in recent years.Considering voltage ratings of the power inverter,the current constraint of the induction machine and the limit of maximum slip frequency adequately,the optimal current vector locus for maximum torque operation was derived by mathematical method,based on which the guidelines for the implementation of current optimizing strategy was summarized.Then,following the design guidelines an alternative control algorithm was developed,which could guarantee the good smooth transition between constant torque region and flux-weakening regions.Experimental results were presented to verify the validity of the analysis,which achieves the maximum torque operation over a wide speed range and the highly dynamic response performance.