摘  要：建立了考虑铁损时的感应电机数学模型，在分析电机损耗和定子磁链的关系的基础上，提出了一种通过优化定子磁链实现感应电机直接转矩控制变频调速系统的效率最优控制策略。研究了不同负载转矩和转速条件下电机损耗与定子磁链之间关系，推导出电机损耗与负载转矩和定子磁链的表达式，进而确定了损耗极小时的最优定子磁链幅值。仿真结果表明该策略能明显降低感应电机直接转矩控制系统的功率损耗，提高运行效率。
关键词：感应电机；直接转矩控制；损耗模型；效率优化

Abstract: The mathematical model of induction motor considering iron loss was established. Based on the analysis of the relationship between the motor losses and the stator flux magnitude,the efficiency optimization control strategy of direct torque controlled induction motor drives,which minimizes the motor losses by optimizing the stator flux magnitude,was proposed.The relationship between the motor losses and the stator flux in different load torque and speed was investigated in details.And the expression among power losses,load torque and the stator flux was deduced.Consequently,the value of stator flux magnitude which minimizes power losses was determined.The simulation results show that the proposed optimization control strategy can significantly reduce the motor losses of the driving system and improve the operational efficiency.
Key words: induction motor; direct torque control; loss model; efficient optimization