基于幂次混合趋近律的Buck变换器滑模控制方法研究

针对基于传统指数趋近律的Buck变换器滑模控制方法存在收敛速度慢、动态响应不平滑等缺点,提出一种基于幂次混合趋近律的滑模控制方法。引入幂次项,提高系统收敛速度;引入反双曲正弦函数项,减少超调量,随系统状态调节滑模抖振。系统平衡点附近的抖振由反双曲正弦函数参数决定,给出切换带详细计算方法。幂次混合趋近律具有二阶滑模特性,系统能在有限时间内到达滑模面。将该方法应用于Buck变换器二阶滑模控制器,给出滑模面参数选择方法。仿真和实验数据表明,提出的幂次混合趋近律滑模控制方法能有效提高系统收敛速度,减小超调量,增强稳态精度。

Research on Buck Converter Sliding Mode Control Method Based on Power Maxing Reaching Law

In view of the shortcomings of Buck converter sliding mode control method based on traditional exponential reaching law,such as slow convergence speed and unsmooth dynamic response,a sliding mode control method based on power maxing reaching law was proposed.Power terms were introduced to improve the system convergence speed;inverse hyperbolic sine function terms were introduced to reduce overshoot and adjust sliding mode chattering with system state.The chattering near equilibrium point of the system was determined by the parameters of inverse hyperbolic sine function,and a detailed calculation method of switch zone was given.The power mixing reaching law has second-order sliding model property,and the system can reach sliding mode surface in a limited time.This method was applied to the second-order sliding mode controller of Buck converter,and a method for selecting sliding mode parameters was given.Simulation and experimental data show that the power mixed reaching law sliding mode control method proposed can effectively improve system convergence speed,reduce overshoot,and enhance steady-state accuracy.