基于滑膜控制的异步电机直接转矩控制研究

Research on Direct Torque Control of the Asynchronous Motor Based on Sliding Mode Control

三相异步电机直接转矩控制(DTC)是基于异步电机动态数学模型的高性能变频调速技术,其控制方式具有快速的转矩响应和良好的参数鲁棒性,但速度波动大,响应恢复时间较长,抗干扰性较差。针对常规PI型DTC系统存在的不足,在分析直接转矩控制策略的基础上,应用基于滑模控制的DTC策略,建立了基于滑模控制的异步电机的数学模型,速度控制器采用指数趋近率进行设计,证明了其转矩和磁链控制的收敛性,应用滑模控制的可行性。建模仿真分析结果表明,基于滑模控制的DTC相对于常规DTC,具有转矩脉动小、响应速度快、鲁棒性和抗干扰能力强等特点。可为设计高性能的异步电机控制系统提供一定的参考。

Direct torque control(DTC)of three-phase asynchronous motor is based on the high-performance variable frequency speed regulation technology of asynchronous motors dynamic mathematical model,which possess fast torque response and good robustness,but large speed fluctuation,long response recovery time and poor anti-interference.Against the shortcomings of conventional PI-DTC system,the sliding mode control-based DTC strategy is applied to establish the mathematical model of the asynchronous motor based upon the analysis of direct torque control strategy,while the exponential approach rate is adopted to design the speed regulator,to prove the astringency of the torque&magnetic chain control as well as the feasibility of application of sliding mode control.The modeling simulation results show that the sliding mode control-based DTC strategy has the characteristics of lower torque pulsation,faster response,better robustness and strong anti-interference ability when compared with the conventional DTC,thus,able to provide reference in the field of designing the high performance control system for asynchronous motors.