Sliding mode control of synchronous Buck converter based on variable speed reaching law

Stable output voltage is the basic requirement of DC converter to guarantee the performance of the converter under the condition of input voltage and load disturbance. For the problems of error and unreliable convergence of output voltage when traditional sliding mode control is adopted for synchronous Buck converter, a sliding mode control strategy with new variable speed reaching law is proposed. A new variable speed reaching law is constructed. A linear state observer is used to calculate the estimated value of input voltage and load. The control signal is obtained by combining the estimated value with dual-integral sliding mode surface and reaching law. The simulation and experimental results show that the proposed control strategy improves the convergence recovery speed is about 51% higher than that of the traditional dual-integral sliding mode control after the reference voltage changes, and the voltage fluctuation range is about 50% smaller, and improves the robustness of the system.