改进定时扰动观测器的三电平PFC自适应滑模控制策略OA

To enhance the robustness of a system under complex disturbances such as voltage fluctuations and load jumps on the grid-side,an adaptive sliding mode control scheme based on an improved fixed-time disturbance observer is proposed in this paper,which uses a single-phase bridgeless three-level power factor correction(PFC)circuit.With the adoption of an improved fixed-time disturbance observer instead of a traditional extended state observer,the accu-rate estimation and compensation of system disturbances can be achieved.In addition,a dynamic sliding mode control-ler based on an adaptive exponential convergence law is put forward,which dynamically adjusts the switching gain to ef-fectively suppress the inherent chattering of sliding mode control while significantly improving the robustness of the sys-tem with respect to parameter changes,grid-side voltage fluctuations and load jumps.Through simulation experiments and a comparison with traditional control methods,results show that the adaptive sliding mode control strategy with the improved fixed-time disturbance observer can effectively reduce chattering and significantly improve the system's dy-namic response performance and steady-state accuracy,proving the correctness of the proposed control scheme.