中文摘要：

为改善Buck变换器动态性能,将线性、非线性控制算法相结合,负载稳定时采用电压模式线性控制,负载突变时采用电容充放电平衡非线性控制算法以提高动态特性。对电容充放电平衡控制Buck变换器的动态过程进行理论分析,由于负载在开关周期的不同时刻发生正/负跳变时,电容充放电荷量不相同,其动态响应也不一样。采用电容充放电平衡控制策略,负载在电感电流最大时发生正跳变变换器具有最好的动态特性,反之在相同时刻发生负跳变则具有最不理想的动态过程。对采用电压模式与电容充放电平衡两种控制算法的Buck电路进行负载突变的对比仿真研究。仿真结果验证了理论分析的正确性及电容充放电平衡控制算法的优良动态控制特性。

英文摘要：

A control algorithm combing linear and nonlinear control is introduced based on the principle of capacitor charge balance to achieve good dynamic response of Buck converter.The proposed algorithm chooses linear voltage mode control when the load is stable,nonlinear control will be chosen during load transient.Because the quantity of capacitor charge during the transient is different when load current steps at different phase of one switching cycle,the dynamic responses are not the same.With the strategy of ca-pacitor charge balance control,the best dynamic response can be obtained when load current steps positive-ly at the maximum of inductor current.On the contrary,the worst dynamic performance will occur when load current steps negatively at the same time.The Buck converter based on capacitor charge balance con-trol was simulated as well as voltage mode control for comparison.Simulation results verify the rightness of theoretical analysis and the superior dynamic performance of capacitor charge balance control.