铁道科学与工程学报2025，Vol.22Issue(2)：829-840,12.DOI:10.19713/j.cnki.43-1423/u.T20240681
飞跨电容型三电平Buck变换器双闭环控制研究
Research on double closed loop control of flying-capacitor three-level Buck converter
摘要
Abstract
Flying-capacitor three-level Buck converter has been widely used in rail transit charging system because of its low output voltage,current harmonics,and low voltage stress of switching tube.To enhance the control quality of the output current and voltage,while maintaining neutral-point potential balance,a dual closed loop method that combines model predictive control with active disturbance rejection control was proposed,based on the decoupling of output voltage and flying capacitor voltage.The current inner loop adopted a continuous set model predictive control with the introduction of the flying capacitor voltage regulation rate factor.The switching frequency of this method was fixed,and the weight coefficient of the evaluation function does not need to be adjusted,which reduces the difficulty of controller design.The external constant current charging condition and midpoint potential balance control were realized by fine tuning the duty ratio of the switching tube.The stability of the inner loop was analyzed by using Lyapunov theory.The active disturbance rejection control based on particle swarm parameter optimization was used in the voltage outer loop to estimate and compensate the disturbance such as sudden load change in real time,which improved the immunity of the system and meets the demand of external constant voltage charging conditions.The double closed-loop structure limited the maximum peak current of the converter and ensured the reliable operation of the converter.At 50 kHz switching frequency,simulation and semi-physical experiments were carried out.The results show that the proposed control strategy can stabilize the flying-span capacitor voltage at half of the input voltage and ensure the balance of midpoint potential.On this basis,constant current and constant voltage output were realized.For the output current single loop control,the model predictive control has a faster response speed than PI controller.For the voltage-current double closed loop control,the response time of the proposed control strategy is 44%higher than that of the PI double closed loop control.When the input voltage and load resistance change abruptly,the proposed control strategy has smaller output voltage overshot and shorter adjustment time compared with the PI control.关键词
飞电容三电平降压变换器/解耦控制/模型预测控制/最优控制律/自抗扰控制Key words
flying capacitor three-level buck converter/decoupling control/model predictive control/optimal control law/active disturbance rejection control分类
动力与电气工程引用本文复制引用
韩锟,马晓慧,李蔚..飞跨电容型三电平Buck变换器双闭环控制研究[J].铁道科学与工程学报,2025,22(2):829-840,12.基金项目
广西科技重大专项资金资助项目(桂科AA20302010) （桂科AA20302010）
