恒定导通时间电容电流控制Buck变换器研究  

Research on the Constant On-time Capacitor Current Control of Buck Converters

作　　者：张希[1] 沙金[1] 徐杨军[1] 许建平[1] 陈兴[1] 

机构地区：[1]磁浮技术与磁浮列车教育部重点实验室西南交通大学电气工程学院,成都610031

出　　处：《电工技术学报》2015年第23期18-23,共6页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51177140;61371033)资助项目

摘　　要：由于输出电容电压相位滞后电感电流相位,当输出电容等效串联电阻(ESR)较小时,恒定导通时间V^2(V^2-COT)控制Buck变换器将工作在不稳定状态。针对该问题,提出开关变换器的恒定导通时间电容电流(CC-COT)控制技术,并阐述了其工作原理。通过基于描述函数法建立的小信号模型和Routh-Hurwiz判据,研究CC-COT控制Buck变换器的稳定性。研究结果表明,CC-COT控制技术具有快速瞬态响应速度,且不存在因输出电容ESR较小而引起的不稳定现象。For the constant on-time V^2（ V^2-COT） controlled buck converter, when the output capacitor with small equivalent series resistance（ ESR） is used,it will operate in the unstable state because the output voltage phase lags behind the inductor current phase. To solve the problem,a constant on-time capacitor current（ CC-COT） control technique for switching converter is proposed and its operational principle is elaborated. Based on the small signal model established by describing function method,the stability of CC-COT controlled buck converter is studied by using the Routh-Hurwitz criterion. The study results show that the CC-COT control technique has fast transient response characteristic and can eliminate the instability caused by the small ESR of the output capacitor.

关 键 词：电容电流 恒定导通时间V2控制 等效串联电阻 稳定性 瞬态响应 

分 类 号：TM315[电气工程—电机]