中国电机工程学报2018，Vol.38Issue(1)：242-249,后插25,9.DOI:10.13334/j.0258-8013.pcsee.162408
PI补偿固定关断时间电流型控制Boost变换器的次谐波振荡机理及失稳边界
Subharmonics Oscillation Mechanism and Instability Boundary of Fixed Off-time Current-mode Controlled Boost Converter With PI Compensator
摘要
Abstract
When outer voltage loop with high feedback gain or output capacitor with large equivalent series resistance (ESR) is used, subharmonic oscillation will occur in fixed off-time current-mode (FOT-CM) controlled boost converter with proportional-integral (PI) compensator, leading to the converter in unstable state. Due to compensation capacitor voltage in outer voltage loop is the linear combination of inductor current and output capacitor voltage of the power stage, a reduced-order discrete-time model of FOT-CM controlled boost converter with PI compensator is established. Based on the model, the stability effects of feedback gain of outer voltage loop and output capacitor ESR on FOT-CM controlled Boost converter with PI compensator is studied and its subharmonic oscillation mechanism is investigated. Furthermore, an approximate reduced-order discrete-time model is obtained, by which the corresponding approximate critical stability condition is derived. The results indicate that when output capacitor ESR is small, FOT-CM controlled boost converter with PI compensator loses stability by period- doubling bifurcation with variation of feedback gain of PI compensator. Besides, the converter loses stability by border-collision bifurcation with variation of output capacitor ESR. To avoid subharmonic oscillation in the converter, output capacitor with small ESR and PI compensator with small feedback gain should be chosen. The theoretical analysis is verified by experimental results.关键词
Boost变换器/固定关断时间电流型控制/比例积分补偿器/等效串联电阻/次谐波振荡Key words
Boost converter/fixed off-time current-mode (FOT-CM) control/proportional-integral (PI) compensator/equivalent series resistance (ESR)/subharmonic oscillation分类
信息技术与安全科学引用本文复制引用
张希,许建平,许多,陈诚,张凯暾..PI补偿固定关断时间电流型控制Boost变换器的次谐波振荡机理及失稳边界[J].中国电机工程学报,2018,38(1):242-249,后插25,9.基金项目
国家自然科学基金项目(51177140,61371033). Project Supported by National Natural Science Foundation of China (51177140, 61371033). （51177140,61371033）
