基于滑模变结构控制策略的直流斩波器设计

Design of DC-DC chopper based on sliding mode control theory

为稳定气压系统废气能量回收系统中输出的电压,需采用直流斩波器。传统的直流斩波控制电路采用微处理器使用PID等经典的控制策略,不适合具有大扰动的非线性直流斩波器的控制。分析了升降压直流斩波电路连续状态下的结构,采用滑动变结构控制方法对其进行控制。仿真结果表明,与传统的控制策略相比,滑动变结构控制方法可保证直流斩波器在趋近运动阶段有较短的上升时间,在滑动模态阶段有较小的超调量,从而具有良好的动态品质。

A DC-DC chopper is employed in the exhaust gas recycling system to stable the output voltage oi the system. As the process of DC-DC chopping is non-linear with considerable disturbance, it is difficult to achieve the best performance by using traditional control approaches such as PID etc. Based on the analysis of the Buck-Boost chopper in continuous conduction mode, sliding mode control strategy is utilized. Simulation demonstrates that the sliding mode control method can achieve excellent results with shorter rising time on start stage and small system overshoot on sliding mode, which ensures a better dynamical performance of the system.