飞跨电容钳位型三电平变换器飞跨电容电压移相控制策略研究  

Research on Phase-shifting Control Strategy of Flying Capacitor Voltage for Flying Capacitor Clamped Three-level Converter

作　　者：米慧瑶 宋磊[1] 刘潇奎 段善旭[1] MI Huiyao;SONG Lei;LIU Xiaokui;DUAN Shanxu(State Key Laboratory of Advanced Electromagnetic Technology(School of Electrical and Electronic Engineering,Huazhong University of Science and Technology),Wuhan 430074,China)

机构地区：[1]强电磁技术全国重点实验室(华中科技大学电气与电子工程学院),武汉430074

出　　处：《电源学报》2025年第2期86-95,共10页Journal of Power Supply

摘　　要：飞跨电容钳位型三电平变换器具有降低开关管的电压应力、减小滤波电感体积等优势。变换器工作时,飞跨电容电压需要稳定在高压侧电压的一半,常采用调节占空比的控制策略,但该方法存在飞跨电容电压与输出电压控制耦合的问题,在飞跨电容电压调节过程中电感电流波动较大。针对这一问题,分析了移相控制策略实现飞跨电容电压与输出电压控制解耦的优势,并深入分析其控制特性。通过建立飞跨电容电压的谐波模型,分析了飞跨电容电压与移相角的关系。建立飞跨电容电压受开关管占空比D和移相角度?φ之间的低次谐波函数关系,并结合时域模型划定出移相控制的有效占空比区间,以及使得移相控制性能最优的占空比。建立仿真模型并搭建了1台3.6 kW的实验样机,将移相调节与占空比调节的飞跨电容电压控制策略进行对比,验证了移相控制的解耦优势以及控制特性。The flying capacitor clamped three-level converter has many advantages,e.g.,it can reduce the voltage stress of a switch and the volume of a filter inductor.Under its operation,it is necessary to stabilize the flying capacitor voltage at half of the high-voltage side voltage,so a control strategy of adjusting the duty cycle is often used.However,this method has the problem of coupling control between flying capacitor voltage and output voltage,resulting significant fluctuations of inductance current in the process of flying capacitor voltage regulation.To solve this problem,the advantages of using the phase-shifting control strategy to realize the decoupling control of flying capacitor voltage and output volt-age are analyzed,and the corresponding control characteristics are also studied.Through the establishment of a harmonic model of flying capacitor voltage,the relationship between flying capacitor voltage and phase-shifting angle is given.A low-order harmonic function relationship is constructed,which indicates that the flying capacitor voltage is affected by the switch duty cycle D and phase-shifting angleΔφ.The effective duty cycle interval of phase-shifting control and the duty cycle that optimizes the performance of phase-shifting control are delimited by combining with a time-domain model.A simulation model was established,and an experimental prototype with 3.6 kW was built.The control strategies of adjusting flying capacitor voltage based on phase-shifting angle and duty cycle are compared to verify the decoupling advantages and control characteristics of phase-shifting control.

关 键 词：飞跨电容 移相控制 解耦控制 有效区间 

分 类 号：TM46[电气工程—电器]