邻周期采样的数字控制 DC-DC 开关变换器

摘要

针对高频DC-DC开关变换器，提出了数字控制DC-DC开关变换器的邻周期采样（ adjacent cycle sampling ，ACS）控制方法，缓解硬件处理速度与系统瞬态性能之间的矛盾。依据纹波控制方法，ACS控制算法利用硬件空闲阶段采样数据，增大环路预留时间，消除占空比的影响。采用ACS控制算法，推导出适用于后缘调制降压型DC-DC开关变换器的数字V2控制律和电流控制律，并且研究了次谐振荡现象及其数字斜坡补偿消除方法。仿真结果表明，在相同的硬件条件，对于负载的瞬间扰动，数字V2控制较数字电流控制具有更快的瞬态响应速度；与现有技术相比，ACS控制方法可有效提高系统的瞬态响应性能。%Adjacent cycle sampling ( ACS) control method applied to high switching frequency converters for the digitally controlled DC-DC switching converters was proposed .ACS control method can effectively relieve the contradiction between hardware processing speed and transient response performance .Accord-ing to ripple control method,ACS control method sampling the data in idle time increased the available time for duty ratio updating ,and furthermore it was irrelevant to duty ratio .For the buck DC-DC switching converters with trailing-edge modulation ,the control laws of both the digital V 2 control and the digital cur-rent control were derived based on ACS control method .Moreover ,the harmonic oscillation phenomenon of above control laws was analyzed and eliminated using digital slope compensation method .The simula-tion results show that ,for the load instantaneous disturbance ,the digital V 2 control has faster transient re-sponse speed than the digital current control under the same hardware resources .As compared with the conventional technologies ,the ACS control method can effectively improve the transient response perform-ance of DC-DC converters .