七电平有源中点钳位式逆变器中飞跨电容电压平衡的移相调控方法

doi:10.19595/j.cnki.1000-6753.tces.242148

Abstract
Figure/Table
References
Related Citation (15)

Download: PDF (4594 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract The 7-level active neutral point clamped (ANPC) topology effectively reduces the need for filter inductance, offering the potential for higher power density and efficiency. However, under phase-shifted pulse width modulation (PS-PWM), the voltage regulation capability of the flying capacitors is limited, and imbalances in flying capacitor voltage can degrade converter reliability and output power quality. This paper proposes a flying capacitor voltage regulation method based on PS-PWM. This method adjusts the PWM phase of the flying capacitor unit to modulate the ripple shape of the inductor current, thereby modifying the charging/discharging current of the flying capacitor. The method is fundamentally unaffected by load current polarity and does not alter the effective duty cycle of the converter output.
In the 0~1/3 modulation range, the charging current of the source-side flying capacitor is primarily related to the inductor current during the high-level period of the PWM-A signal near the source side. It is independent of the high-level periods of PWM-B and PWM-C signals. Moreover, the high-level period of the PWM-A signal does not affect the charging and discharging process of the load-side flying capacitor. Given a duty ratio D, adjusting the phase φ_A of the PWM-A signal can linearly modulate the average amplitude of the corresponding inductor current ripple without changing its ripple duration. This adjustment allows precise control of the source-side flying capacitor’s charge over the switching period, thereby regulating its voltage. During this process, the charging/discharging state of the flying capacitor only occurs during the high-level periods of the PWM-A, PWM-B, and PWM-C signals. By ensuring that the high-level periods of the PWM signals do not overlap, the source-side flying capacitor voltage can be independently controlled without affecting the load-side flying capacitor. Similarly, adjusting the phase φ_C of the PWM-C signal can linearly modulate the discharge current amplitude of the load-side flying capacitor. As long as the high-level periods of the PWM signals do not overlap, the load-side flying capacitor voltage can be independently controlled.
In the 1/3~2/3 modulation range, changes in the PWM signal phases affect the flying capacitor’s charging and discharging current amplitude and duration. By deriving the phase-shift modulation model of the average charging current of the source-side and load-side flying capacitors over the switching period concerning the PWM-A and PWM-C signal phases φ_A and φ_C, the charging/discharging states of the two-stage flying capacitors can be determined under the single PWM phase degree of freedom. An appropriate voltage modulation strategy can be selected depending on the degree of flying capacitor voltage offset. Subsequently, adjusting the phases of PWM-A or PWM-C can improve the voltage offset of the flying capacitors and optimize the voltage balance between the source and load-side flying capacitors.
In the 2/3~1 modulation range, the charging and discharging states of the flying capacitors occur during the low-level periods of the PWM-A, PWM-B, and PWM-C signals. The regulation principle in this range is similar to that in the 0~1/3 modulation range. In this case, adjusting the phases φ_A and φ_C of the low-level periods of PWM-A and PWM-C signals can achieve independent and linear voltage regulation for the source-side and load-side flying capacitors.
Thus, the proposed improved PS-PWM phase modulation method can effectively address the voltage imbalance in the flying capacitors over the entire 0~1 modulation range.

Key words： Seven-level active neutral point clamp (ANPC) flying capacitor phase-shifted pulse width modulation (PS-PWM) voltage regulation

Received: 29 November 2024

PACS:

TM464

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Li Xiang
	Feng Hao
	Ran Li

Cite this article:

Li Xiang,Feng Hao,Ran Li. Phase-Shift Method for Seven-Level Active Neutral Point Clamped Inverter Flying Capacitor Voltage Control[J]. Transactions of China Electrotechnical Society, 2025, 40(24): 8066-8079.

URL:

https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.242148 OR https://dgjsxb.ces-transaction.com/EN/Y2025/V40/I24/8066

[1] 张少昆, 孙微, 范涛, 等. 基于分立器件并联的高功率密度碳化硅电机控制器研究[J]. 电工技术学报, 2023, 38(22): 5999-6014.
Zhang Shaokun, Sun Wei, Fan Tao, et al.Research on high power density silicon carbide motor controller based on parallel connection of discrete devices[J]. Transactions of China Electrotechnical Society, 2023, 38(22): 5999-6014.
[2] 王议锋, 车超昌, 陈博, 等. 基于SiC器件的高压宽范围直流辅助电源研究与设计[J]. 电工技术学报, 2025, 40(3): 786-799.
Wang Yifeng, Che Chaochang, Chen Bo, et al.Research and design of high voltage and wide range DC auxiliary power supply based on SiC devices[J]. Transactions of China Electrotechnical Society, 2025, 40(3): 786-799.
[3] 佟强, 刘贺, 曲璐. 基于氮化镓的反激同步整流DC/DC变换器设计[J]. 电源学报, 2024, 22(2): 81-89.
Tong Qiang, Liu He, Qu Lu.Design of synchronous rectifier flyback DC/DC converter based on GaN[J]. Journal of Power Supply, 2024, 22(2): 81-89.
[4] Lei Yutian, Barth C, Qin Shibin, et al.A 2-kW single-phase seven-level flying capacitor multilevel inverter with an active energy buffer[J]. IEEE Transactions on Power Electronics, 2017, 32(11): 8570-8581.
[5] Anderson J A, Hanak E J, Schrittwieser L, et al.All-silicon 99.35% efficient three-phase seven-level hybrid neutral point clamped/flying capacitor inverter[J]. CPSS Transactions on Power Electronics and Applications, 2019, 4(1): 50-61.
[6] 宋磊, 段善旭, 米慧瑶, 等. 输入输出共地型三电平Buck/Boost变换器飞跨电容电压自平衡分析[J]. 中国电机工程学报, 2023, 43(15): 5983-5995.
Song Lei, Duan Shanxu, Mi Huiyao, et al.Self- balance mechanism analysis of the flying capacitor voltage in the three-level Buck/Boost converter with input and output sharing the ground[J]. Proceedings of the CSEE, 2023, 43(15): 5983-5995.
[7] 樊启高, 吕华阳, 毕恺韬, 等. 面向直流储能系统的飞跨电容三电平双向升降压变换器及其模型预测控制策略[J]. 电工技术学报, 2022, 37(16): 4169-4179.
Fan Qigao, Lü Huayang, Bi Kaitao, et al.Flying capacitor three-level bi-directional buck-boost converter and its model predictive control strategy for DC energy storage system[J]. Transactions of China Electrotechnical Society, 2022, 37(16): 4169-4179.
[8] 高娜, 张宇, 关清心, 等. 基于有源中点钳位五电平电路的双有源桥DC/DC变换器[J]. 中国电机工程学报, 2023, 43(5): 1950-1960.
Gao Na, Zhang Yu, Guan Qingxin, et al.Five-level active neutral point clamed dual active bridge DC/DC converter[J]. Proceedings of the CSEE, 2023, 43(5): 1950-1960.
[9] 黄桢楠, 董纪清. 基于PI控制的飞跨电容均压环研究[J]. 电气开关, 2024, 62(3): 12-16.
Huang Zhennan, Dong Jiqing.Research on flying capacitor voltage balance based on PI control[J]. Electric Switchgear, 2024, 62(3): 12-16.
[10] 张琦, 李江江, 孙向东, 等. 单相级联七电平逆变器拓扑结构及其控制方法[J]. 电工技术学报, 2019, 34(18): 3843-3853.
Zhang Qi, Li Jiangjiang, Sun Xiangdong, et al.Topology and control method of single-phase cascaded seven-level inverter[J]. Transactions of China Electrotechnical Society, 2019, 34(18): 3843-3853.
[11] 张元媛, 阮新波. 多电平直流变换器中飞跨电容电压的一种控制策略[J]. 中国电机工程学报, 2004, 24(8): 37-41.
Zhang Yuanyuan, Ruan Xinbo.A novel control strategy for the flying capacitor voltage of the multilevel converter[J]. Proceedings of the CSEE, 2004, 24(8): 37-41.
[12] Vukadinović N, Prodić A, Miwa B A, et al.Extended wide-load range model for multi-level DC-DC converters and a practical dual-mode digital controller[C]//2016 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA, 2016: 1597-1602.
[13] da Silva Carvalho S, Halamíček M, Vukadinović N, et al. Digital PWM for multi-level flying capacitor converters with improved output resolution and flying capacitor voltage controller stability[C]//2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL), Padua, Italy, 2018: 1-7.
[14] 刘苗, 洪峰, 尹培培, 等. 复合型级联双Buck飞跨电容五电平逆变器[J]. 电工技术学报, 2015, 30(18): 35-42.
Liu Miao, Hong Feng, Yin Peipei, et al.A hybrid cascaded dual Buck flying-capacitor five-level inverter[J]. Transactions of China Electrotechnical Society, 2015, 30(18): 35-42.
[15] Zhou Dehong, Quan Zhongyi, Li Yunwei.Simplified predictive duty cycle control of multilevel converters with internal identical structure[J]. IEEE Transactions on Power Electronics, 2020, 35(11): 12416-12428.
[16] 向超群, 杜京润, Zhang Xinan, 等. 电容电压平衡的四电平有源中性点钳位逆变器的改进模型预测电流控制[J]. 电工技术学报, 2024, 39(18): 5826-5838.
Xiang Chaoqun, Du Jingrun, Zhang Xinan, et al.An improved model predictive control of four-level active neutral point clamped inverter with balanced capacitor voltage[J]. Transactions of China Elec- trotechnical Society, 2024, 39(18): 5826-5838.
[17] 刘苗, 洪峰, 王成华. 五电平飞跨电容型双降压逆变器[J]. 电工技术学报, 2011, 26(5): 83-87, 94.
Liu Miao, Hong Feng, Wang Chenghua.A novel flying-capacitor dual Buck five-level inverter[J]. Transactions of China Electrotechnical Society, 2011, 26(5): 83-87, 94.
[18] 郭小强, 贺冉, 张纯江. 高压大容量五电平逆变器共模电压抑制研究[J]. 电工技术学报, 2016, 31(3): 1-7.
Guo Xiaoqiang, He Ran, Zhang Chunjiang.Common- mode voltage reduction of high voltage high power five-level inverters[J]. Transactions of China Electro- technical Society, 2016, 31(3): 1-7.
[19] 严干贵, 刘文华, 穆钢, 等. 内蕴电压平衡控制的飞跨电容逆变器的PWM方法[J]. 中国电机工程学报, 2006, 26(4): 119-125.
Yan Gangui, Liu Wenhua, Mu Gang, et al.Flying capacitor multilevel inverter PWM method with intrinsic voltage balancing control[J]. Proceedings of the CSEE, 2006, 26(4): 119-125.
[20] Feng Chunmei, Liang Jun, Agelidis V G.Modified phase-shifted PWM control for flying capacitor multilevel converters[J]. IEEE Transactions on Power Electronics, 2007, 22(1): 178-185.
[21] Stillwell A, Lei Yutian, Pilawa-Podgurski R C N. A method to extract low-voltage auxiliary power from a flying capacitor multi-level converter[C]//2016 IEEE 17th Workshop on Control and Modeling for Power Electronics (COMPEL), Trondheim, Norway, 2016: 1-8.
[22] Stillwell A, Robert C N, Pilawa-Podgurski.A 5-level flying capacitor multi-level converter with integrated auxiliary power supply and start-up[C]//2017 IEEE Applied Power Electronics Conference and Expo- sition (APEC), Tampa, FL, USA, 2017: 2932-2938.
[23] Stillwell A, Candan E, Pilawa-Podgurski R C N. Constant effective duty cycle control for flying capacitor balancing in flying capacitor multi-level converters[C]//2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL), Padua, Italy, 2018: 1-8.
[24] Stillwell A, Candan E, Pilawa-Podgurski R C N. Active voltage balancing in flying capacitor multi- level converters with valley current detection and constant effective duty cycle control[J]. IEEE Transactions on Power Electronics, 2019, 34(11): 11429-11441.
[25] da Silva Carvalho S, Vukadinovic N, Prodic A. Phase-shift control of flying capacitor voltages in multilevel converters[C]//2020 IEEE Applied Power Electronics Conference and Exposition (APEC), New Orleans, LA, USA, 2020: 299-304.