考虑磁饱和的感应电机MTPA转矩控制

摘要

The rotor flux will be changed to obtain the maximum ratio between torque and stator current,under the maximum toque per ampere (MTPA) criteria.Since flux changes with reference torque,not a constant as in conventional vector control algorithm,nonlinear magnetic saturation effect cannot be ignored.In this paper,a control system considering magnetic saturation effect is proposed.Optimal reference rotor flux is found using linear search algorithm,while the rotor flux is estimated using reduced order observer.The observer-error is taken into consideration,when designing flux controller using sliding mode algorithm and torque controller using backstepping algorithm,to ensure the global stability.Simulation and experimental results show the effectiveness of the proposed algorithm.%感应电机的最大转矩电流比(MTPA)控制算法根据需求转矩调节磁链幅值,以达到转矩与定子电流比值的最大化.因磁链随转矩的变化而变化,不再像传统控制算法保持磁场幅值恒定,磁场非线性饱和效应会对控制系统产生影响.针对此问题,该文提出考虑磁饱和特性的MTPA转矩控制系统.根据需求转矩以及饱和模型,通过线性搜索寻找最优磁链目标值,并在计算励磁电流时考虑d轴转子电流的动态特性,用降阶观测器观测转子磁链,并在设计滑模磁链控制器以及反步法设计转矩控制器时考虑观测误差,以确保控制器参数的设置能达到全局稳定.仿真和实验结果证明了所设计控制器的有效性.