串聯(lián)諧振變換器的穩(wěn)態(tài)模型

諧振變換器是依靠改變開關網絡的工作頻率實現(xiàn)對輸出量的控制的，因此它是一種變頻控制的開關調節(jié)系統(tǒng)。像PWM型開關調節(jié)系統(tǒng)一樣，這種開關調節(jié)系統(tǒng)也是一種強非線性、離散的病態(tài)系統(tǒng)，要精確的建立其數(shù)學模型并從理論上得到系統(tǒng)的瞬態(tài)解和穩(wěn)態(tài)解是較為困難的，更不能用經典控制理論設計控制器并研究其穩(wěn)定性。因為在傳輸能量方面，PWM型變換器是靠平均值傳輸能量的，而諧振型變換器是靠“基波”傳輸能量。所以在穩(wěn)態(tài)分析時，PWM型變換器采用平均值分析法，而諧振變換器采用了基波分析法；本文詳細介紹了串聯(lián)諧振變換器穩(wěn)態(tài)模型建立方法。
關鍵詞：串聯(lián)諧振變換器 穩(wěn)態(tài)模型
Steady state model for series resonant converter
Zhang Weiping? Mao Peng?? Xiao Shisheng
College of Information Engineering, China University of Technology
JinYuanZhuang Road NO.5 ShijingShan District Beijing 100041,P.R. China
Email：zwp@ncut.edu.cn

Abstract The output voltage of resonant converter is controlled depending on the changes of the switch network’s frequency. Hence it is called pulse frequency modulation (PFM) system, which is the same nonlinear and discrete ill-conditioned system as the pulse width modulation (PWM) system. It is difficult to model the accurate mathematical building and analyze the transient response as well as the steady state response from the theories. Even worse, the compensating network’s design and the converter’s stability’s study is hard using the classical control theories. The average method is employed to analyze the energy transmission mode of PWM system while the equivalent fundamental wave method is applied in resonant converter, thus PWM converter is modeled by average method while resonant converter is modeled by equivalent fundamental wave method. The steady state model for series resonant converter using this method is introduced detailedly in this paper.
Keyword: series resonant converter???? Steady state model