考虑负载不确定的异步电机效率的优化控制

Optimal Control of Efficiency of Asynchronous Motor Considering Load Uncertainty

针对异步电机在负载变动时运行效率低的问题,提出了一种在直接转矩控制下将损耗模型算法(LMC)与在线搜索控制算法(SC)相结合的混合式定子磁链寻优控制算法。首先,在d-q坐标系下建立了异步电机考虑铁损的精确等效电路;利用电机损耗模型,分析了不同负载转矩下总损耗与定子磁链的关系,推导出了不同负载转矩下效率最优的定子磁链幅值。再结合黄金分割在线搜索法,实现了不同负载下以效率为目标的异步电机最优控制。将该控制算法应用在异步电机直接转矩控制系统中,结果表明该算法兼有LMC和SC的双重优点,具有较好的高效性和有效性,能够显著提高异步电机在负载变动时的运行效率。

In view of the low efficiency of asynchronous motor when the load changes,a hybrid stator flux optimization control algorithm based on loss model algorithm(LMC)and on-line search control algorithm(SC)is proposed in this Direct torque control.Firstly,an accurate equivalent circuit of asynchronous motor considering iron loss is established in d-q coordinate system;using the motor loss model,the relationship between total loss and stator magnetic chain under different load torques is analyzed,and the stator magnetic chain amplitude with optimal efficiency under different load torques is derived.Combined with the golden ratio on-line search method,the optimal control of induction motors under different loads is realized.The control algorithm is applied to the Direct torque control system of induction motor.The results show that the algorithm has the double advantages of LMC and SC,and has better efficiency and effectiveness,it can improve the running efficiency of asynchronous motor when the load changes.