基于非线性积分滑模变结构控制三相VSR的研究

为了提高三相电压型PWM整流器(VSR)对系统参数变化及负载扰动的能力,在传统积分滑模的基础上,提出非线性积分滑模变结构控制策略。该控制策略含有误差和误差积分项,减小稳态误差和抖振的同时又能提高系统的鲁棒性,并在此基础上对积分项进行削弱,防止积分饱和效应(windup)带来超调过大及响应时间过长的问题。采用指数趋近律,提高滑模面上的运动品质,以进一步削弱抖振效应。最后仿真结果表明,非线性积分滑模变结构控制策略与传统积分滑模、双闭环PI相比,该方法使系统具有超调小和更好的抗扰性、跟踪能力。

Study of Three-Phase Voltage-Source PWM Rectifier Based on Nonlinear Integrator Sliding Mode Variable Structure Control

A nonlinear integrator sliding mode of variable structure control strategy,based on traditional integrator sliding mode,was applied in three-phase voltage-source PWM rectifier (VSR) to improve the robustness of parameter uncertainties load disturbance.And this control strategy contains error and error integral term and makes that three-phase voltage-source PWM rectifier not minimize chattering and steady state error but has excellent robustness.Then,integral term is weakened to avoid large overshoots and reduce the state error,which can lead to integral saturation effect (windup).At the same time,an exponential reaching law which can further suppress chatting and improve the reaching speed is presented.The three-phase voltage-source PWM rectifier based on nonlinear integrator sliding mode variable structure control strategy is superior to traditional integrator sliding mode control and the conventional double-loop PI control system in low overshoots,anti-interference and speed tracking by MATLAB simulation.