针对传统的矢量控制因忽略铁损影响而无法对异步电动机实现准确控制的问题,研究了考虑铁损的电动汽车用异步电动机的模糊自适应位置跟踪控制.建立了考虑铁损的异步电动机动态数学模型,利用模糊逻辑系统来逼近异步电动机驱动系统中未知的非线性函数,通过反步设计方法构造了模糊自适应控制器,同时采用李雅普诺夫方法分析了系统的稳定性,并在Matlab环境下进行仿真实验,仿真结果表明,在系统参数未知的情况下,电机位置信号可以快速跟踪期望信号,控制器的性能良好.当t=5s时,负载力矩发生变化,电机仍能跟踪期望信号,说明该控制器能够很好的克服电机参数的不确定性及负载力矩扰动的影响,有较强的鲁棒性,实现了对异步电动机的位置跟踪控制.该控制器结构简单,只有一个自适应参数,减少了系统的在线计算负担,易于工程实现,在电动汽车领域应用前景广阔.
An adaptive fuzzy control based on backstepping technology is designed to reduce the influence of the iron losses which is neglected by the classical vector control. Firstly, the induction motor's dynamic mathematical model including iron losses is established. Then the fuzzy logic systems are used to approxi- mate unknown nonlinearities and an adaptive backstepping is employed to construct controllers. In the end the stability of the system is analyzed by using Lyapunov method. The simulation results show that the new controller overcomees the influences of the parameter uncertainties and guarantees a performance tracking performance. The motor can still track the design signals when the load torque changes, and it il- lustrates that the controller can overcome the influences of the load torque disturbances and has a strong robustness. The controller has a simple structure and only one adaptive law. This will reduce the online computation burden and make it easy to implement in engineering. This study provides an effective way for the development of control system for induction motors in electric vehicles.