Topology and Control Method of Single-Phase Cascaded Seven-Level Inverter
Zhang Qi1, 2, Li Jiangjiang1, Sun Xiangdong1, 2, An Shaoliang1
1. School of Automation and Information Engineering Xi'an University of Technology Xi'an 710048 China; 2. Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology Xi'an 710048 China
Abstract：Traditional multilevel inverters are restrained due to complicated topologies. In this paper, a single-phase cascaded seven-level inverter topology and its control method are presented. The inverter consists of a three-level Boost circuit and a six-switch inverter circuit. The midpoint voltage is adjusted by the controlling of Boost converter, and the intermediate bus capacitor voltage ratio is controlled to 1:2, and seven-level voltage output is achieved. Compared to a traditional multilevel topology, the topology requires fewer switching devices at the same output level, which simplifies the circuit structure. The DC bus capacitor voltage control is the key to the system stability. The mathematical model of the voltage control system is established, and the voltage control method is studied to achieve the effective operation of the inverter. Finally, simulation and experimental results verify the feasibility of the proposed circuit topology and the theoretical analysis.
张琦, 李江江, 孙向东, 安少亮. 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, An Shaoliang. Topology and Control Method of Single-Phase Cascaded Seven-Level Inverter. Transactions of China Electrotechnical Society, 2019, 34(18): 3843-3853.
[1] 甘雪, 曹太强, 林玉婷, 等. 具有分压电容平衡功能的新型组合九电平逆变器[J]. 电工技术学报, 2017, 32(增刊1): 196-202. Gan Xue, Cao Taiqiang, Lin Yuting, et al.A new simplificated combination nine level inverter with the function balancing partial voltage capacitances[J]. Transactions of China Electrotechnical Society, 2017, 32(S1): 196-202. [2] Wu Jinnchang, He Mao-Jhang, Jou Hurng-Liahng.New five-level inverter-based grid-connected power conversion interface[J]. IET Power Electronics, 2013, 6(7): 1239-1247. [3] 徐帅, 张建忠. 多电平电压源型逆变器的容错技术综述[J]. 电工技术学报, 2015, 30(21): 39-50. Xu Shuai, Zhang Jianzhong.Overview of fault- tolerant techniques for multilevel voltage source inverters[J]. Transactions of China Electrotechnical Society, 2015, 30(21): 39-50. [4] Hammond P W.A new approach to enhance power quality for medium voltage AC drives[J]. IEEE Transactions on Industry Applications, 1997, 33(1): 202-208. [5] Nabae A, Takahashi I, Akagi H. A new neutral-point clamped PWM inverter[J]. IEEE Transactions on Industry Applications, 1981, IA-17(5): 518-523. [6] Meynard T A, Foch H, Thomas P, et al.Multicell converters: basic concepts and industry applications[J]. IEEE Transactions on Industrial Electronics, 2002, 49(5): 955-964. [7] 绳伟辉, 葛琼璇. 一种新型七电平有源中点钳位型逆变器的拓扑结构及其换流策略[J]. 中国电机工程学报, 2017, 37(23): 6962-6970, 7087. Sheng Weihui, Ge Qiongxuan.A novel seven-level ANPC inverter topology and its commutating strategies[J]. Proceedings of the CSEE, 2017, 37(23): 6962-6970, 7087. [8] Barbosa P, Steimer P, Steinke J, et al.Active- neutral-point-clamped (ANPC) multilevel converter technology[C]//2005 European Conference on Power Electronics and Applications, Dresden, Germany, 2005, DOI: 10.1109/EPE.2005.219713. [9] 胡存刚, 胡军, 陈权, 等. 基于特定谐波消除PWM的三电平有源中点钳位逆变器共模电压抑制方法[J]. 电工技术学报, 2016, 31(16): 93-102. Hu Cungang, Hu Jun, Chen Quan, et al.Active neutral-point-clamped selective harmonics elimination PWM neutral-point potential common-mode voltage[J]. Transactions of China Electrotechnical Society, 2016, 31(16): 93-102. [10] 王奎, 郑泽东, 李永东, 等. 基于五电平有源中点钳位型双PWM变换器的异步电机矢量控制系统[J].电工技术学报, 2014, 29(2): 247-252. Wang Kui, Zheng Zedong, Li Yongdong, et al.Vector control system for induction motors based on five-level active neutral-point-clamped dual-PWM converter[J]. Transactions of China Electrotechnical Society, 2014, 29(2): 247-252. [11] 王奎, 郑泽东, 李永东. 五电平有源中点钳位型逆变器母线中点电压平衡问题[J]. 中国电机工程学报, 2012, 32(3): 30-35, 19. Wang Kui, Zheng Zedong, Li Yongdong.Neutral- point potential balancing problem of five-level active neutral-point-clamped inverter[J]. Proceedings of the CSEE, 2012, 32(3): 30-35, 19. [12] 何凯益, 任磊, 龚春英, 等. 单一直流源的七电平混合级联逆变器[J]. 电工技术学报, 2016, 31(18): 83-91. He Kaiyi, Ren Lei, Gong Chunying, et al.The hybrid cascaded inverter with single voltage source[J]. Transactions of China Electrotechnical Society, 2016, 31(18): 83-91. [13] 李和明, 王毅, 石新春, 等. 混合级联型多电平变频器拓扑结构研究[J]. 中国电机工程学报, 2006, 26(2): 127-132. Li Heming, Wang Yi, Shi Xinchun, et al.Rsearch on the topology of hybrid cascaded multilevel con- verters[J]. Proceedings of the CSEE, 2006, 26(2): 127-132. [14] 陈仲, 许亚明, 刘亚云, 等. 一种适用于混合级联多电平逆变器的LS-PWM方法[J]. 中国电机工程学报, 2016, 36(23): 6490-6500, 6616. Chen Zhong, Xu Yaming, Liu Yayun, et al.A level- shifted pulse width modulation strategy for hybrid cascaded multilevel converters[J]. Proceedings of the CSEE, 2016, 36(23): 6490-6500, 6616. [15] Hagiwara M, Akagi H.Control and experiment of pulse width-modulated modular multilevel con- verters[J]. IEEE Transactions on Power Electronics, 2009, 24(7): 1737-1746. [16] 王奎, 郑泽东, 李永东. 基于新型模块化多电平变换器的五电平PWM整流器[J]. 电工技术学报, 2011, 26(5): 34-38. Wang Kui, Zheng Zedong, Li Yongdong.A five-level PWM rectifier based on new modular multilevel converter[J]. Transactions of China Electrotechnical Society, 2011, 26(5): 34-38. [17] Hsieh C H, Liang T J, Tsai S W.Design and implementation of a novel multilevel DC-AC inverter[C]//2014 IEEE Energy Conversion Congress and Exposition (ECCE), Pittsburgh, PA, 2014: 5743-5748. [18] Choi J S, Kang F S.Seven-level PWM inverter employing series-connected capacitors paralleled to a single DC voltage source[J]. IEEE Transactions on Industrial Electronics, 2015, 62(6): 3448-3459. [19] Matsumoto H, Shibako Y, Neba Y.Single-phase inverter with energy buffer and DC-DC conversion circuits[J]. IEEE Transactions on Power Electronics, 2017, 32(10): 7615-7625. [20] Rahim N A, Chaniago K, Selvaraj J.Single-phase seven-level grid-connected inverter for photovoltaic system[J]. IEEE Transactions on Industrial Elec- tronics, 2011, 58(6): 2435-2443. [21] Liu Junfeng, Wu Jialei, Zeng Jun.A novel nine-level inverter employing one voltage source and reduced components as high-frequency AC power source[J]. IEEE Transactions on Power Electronics, 2017, 32(4): 2939-2947. [22] 曾君, 吴佳磊, 刘俊峰, 等. 一对基于开关电容原理的多电平高频逆变器[J]. 电工技术学报, 2018, 33(6): 1312-1319. Zeng Jun, Wu Jialei, Liu Junfeng, et al.A pair of high-frequency multilevel inverters based on switched- capacitor technique[J]. Transactions of China Elec- trotechnical Society, 2018, 33(6): 1312-1319. [23] Wu Jinn Chang, Chou Chia Wei.A solar power generation system with a seven-level inverter[J]. IEEE Transactions on Power Electronics, 2014, 29(7): 3454-3462. [24] 何凯益, 任磊, 龚春英, 等. 单一直流源的七电平混合级联逆变器[J]. 电工技术学报, 2016, 31(18): 83-91. He Kaiyi, Ren Lei, Gong Chunying, et al.The hybrid cascaded inverter with single voltage source[J]. Transactions of China Electrotechnical Society, 2016, 31(18): 83-91. [25] 张钢, 杜会卿, 陈艺铭, 等. 基于相位延迟的三电平Boost变换器中点电位平衡控制策略[J]. 中国电机工程学报, 2017, 37(20): 6050-6058. Zhang Gang, Du Huiqing, Chen Yiming, et al.A midpoint potential balance control strategy based on pulse phase delays of three-level Boost converter[J]. Proceedings of the CSEE, 2017, 37(20): 6050-6058. [26] 祝国平, 阮新波, 王学华, 等. 两级式单相逆变器二次纹波电流的抑制与动态特性的改善[J]. 中国电机工程学报, 2013, 33(12): 72-80. Zhu Guoping, Ruan Xinbo, Wang Xuehua, et al.Suppression of the second harmonic current and improvement of the dynamic performance for two-stage single-phase inverters[J]. Proceedings of the CSEE, 2013, 33(12): 72-80.
2019, Vol. 34 
