基于二阶终端滑模优化的电流环滑模控制

Sliding mode control for current loop by second order terminal sliding mode

针对永磁同步电机电流环存在参数摄动、干扰等不确定因素,提出了一种基于二阶终端滑模优化的电流滑模控制。借助常规滑模控制的设计简单、容易实现等优点,计算得到电机电流环的等效控制量。利用二阶终端滑模设计不确定量的控制量,并引入自适应指数趋近律抑制系统参数摄动和干扰等不确定量。所提出的电流环滑模控制系统进行了稳定性分析,理论上可获得自适应零增益切换函数控制,达到有效抑制"抖振",具有很好的鲁棒性。对仿真和实验波形的计算结果表明:所提出的控制方法提高了电流稳态精度,获得更好的调速性能,且设计简单。

In order to suppress uncertainties caused by parameteric variations and disturbances,a sliding mode control( SMC) optimized by a second order terminal sliding mode control( STSMC) was derived to control current loops in a permanent magnet synchronous motor( PMSM). The equivalent control quantity for the current loop is easily obtained by SMC. The switching control for uncertainties was deduced by STSMC integrated with an adaptive exponential function law. Moreover,the stability of STSMC system was analyzed for current loops,and the gain of the switching function in STSMC can be set small,even to be set theoretic zero. STSMC is effective to suppress the "chattering"and retains the system robustness.The comparative results of simulations and experiments indicate that the current loop control system by STSMC improves the steady state accuracy of the current with the result in a better performance of speed regulation for PMSM,and is easy to implement.