中文摘要：

BUCK变换器中存在诸如系统参数不确定、输入电压变化、输出负载变化等多种扰动，这些扰动对BUCK变换器的输出有很大影响，而采用传统的比例积分控制（proportional integral，PI）方法很难取得满意的控制效果。为此，在传统的PI控制策略的基础上，提出了变参数比例积分（ varia-ble parameters proportional integral，VAPI）控制策略以解决系统干扰的问题。由于VAPI控制器不仅具有传统PI控制器瞬态响应速度快和消除静态误差等的优点，同时还能在不同的阶段调整相应的参数，使得BUCK变换器在每个阶段都有更好的特性。首先用变参数比例积分器替换常规的比例积分器，然后设计扰动观测器观测出参数摄动与负载变化带来的系统扰动，将其作为补偿量补偿到前馈通道，提高系统的收敛速度与抗扰动能力，最后通过仿真和实验，分别验证了该算法的有效性。

英文摘要：

There are a variety of disturbances existing in the BUCK converter, including uncertain param-eters, input voltage variation and load changes.These disturbances have a significant impact on output BUCK converter.By using traditional proportional integral （ PI） control the method,it is difficult to a-chieve satisfactory control effect.By the traditional PI control method it is difficult to obtain satisfactory performance.Based on the traditional PI control strategy（variable parameters proportional integral, VA-PI） control strategy was proposed to address the problem of interference system.Since VAPI controller not only has the advantage of traditional PI controller fast transient response and eliminating static error, etc.,but also adjusts the corresponding parameters at different stages, so BUCK converter in each stage has better characteristics.Conventional proportional integrator was replaced by a first variable parameter proportional integral,and the disturbance observer was designed to observe the parameter perturbation and load variations caused by system disturbances, as compensation to compensate feedforward channel and to improve the convergence speed of the system and disturbance rejection.Finally,simulation and experi-ments proved the validity of the algorithm respectively.