Abstract:In view of the shortcomings of the existing modulation strategy applied to cascaded H-bridge (CHB) inverter, a novel power balance modulation strategy was proposed in this paper. This strategy combines the advantages of the carrier phase shift (CPS) modulation strategy and carrier disposition (PD) modulation strategy. By reconstructing the triangular carriers in improved CPS modulation strategy, a new carriers arrangement still retaining the characteristics of carrier phase shift was obtained. Compared with PD modulation strategy, the proposed modulation strategy has the same output voltage harmonic characteristics. Therefore, under the novel power balance modulation strategy proposed in this paper, the output power of the cascaded cells can be self-balanced, and the harmonic characteristics of the inverter output line voltage can be improved effectively. Taken three-cell cascaded multilevel inverter as an example, the method of carriers reconstruction and the principle of proposed power balance modulation strategy were provided. The time required for power balance was also analyzed. Simulation and experimental results verified the validity of the proposed strategy.
许亚明, 陈仲, 那显龙, 孙健博. 基于载波重构的级联逆变器功率均衡调制策略[J]. 电工技术学报, 2018, 33(12): 2831-2840.
Xu Yaming, Chen Zhong, Na Xianlong, Sun Jianbo. Power Balance Modulation Strategy Based on Carrier Reconstruction for Cascaded Inverter. Transactions of China Electrotechnical Society, 2018, 33(12): 2831-2840.
[1] Marchesoni M, Mazzucchelli M, Tenconi S.A non conventional power converter for plasma stabili- zation[J]. IEEE Transactions on Power Electronics, 1990, 5(2): 212-219. [2] 王付胜, 张德辉, 戴之强, 等. 级联H桥光伏并网逆变器混合调制策略[J]. 电工技术学报, 2016, 31(1): 137-145. Wang Fusheng, Zhang Dehui, Dai Zhiqiang, et al.A hybrid control scheme of cascaded h-bridge inverters for grid-connection photovoltaic systems[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(1): 137-145. [3] 张勇军, 姚智聪, 王京, 等. 一种级联H桥型静止无功发生器电容电压平衡控制策略[J]. 中国电机工程学报, 2014, 34(27): 4621-4628. Zhang Yongjun, Yao Zhicong, Wang Jing, et al.A direct current capacitor voltage balancing control strategy for H-bridge cascaded static var generator[J]. Proceedings of the CSEE, 2014, 34(27): 4621-4628. [4] Perez M, Kouro S, Rodriguez J, et al.Modified staircase modulation with low input current distortion for multicell converters[C]//Proceedings of 2008 IEEE Power Electronics Specialists Conference (PESC), Rhodes, Greece, 2008: 1989-1994. [5] Dahidah M S A, Agelidis V G. Selective harmonic elimination PWM control for cascaded multilevel voltage source converters: a generalized formula[J]. IEEE Transactions on Power Electronics, 2008, 23(4): 1620-1630. [6] 江友华, 曹以龙, 龚幼民. 基于载波移相角度的级联型多电平变频器输出性能的研究[J]. 中国电机工程学报, 2007, 27(1): 76-81. Jiang Youhua, Cao Yilong, Gong Youmin.Research on the cascade multilevel inverter based on different carrier phase-shifted angle[J]. Proceedings of the CSEE, 2007, 27(1): 76-81. [7] 蔡信健, 吴振兴, 孙乐, 等. 直流电压不均衡的级联H桥多电平变频器载波移相PWM调制策略的设计[J]. 电工技术学报, 2016, 31(1): 119-127. Cai Xinjian, Wu Zhenxing, Sun Le, et al.Design for phase-shifted carrier pulse width modulation of cascaded H-bridge multi-level inverters with non- equal DC voltages[J]. Transactions of China Electro- technical Society, 2016, 31(1): 119-127. [8] Razi A, Wahab A S A, Shukor S A A. Improved wave shape-pattern performance using phase opposite disposition (POD) method for cascaded multilevel inverter[C]//Proceedings of 2016 IEEE 2nd Annual Southern Power Electronics Conference(SPEC), Auckland, New Zealand, 2016: 1-6. [9] 杨晓冬, 王崇林, 史丽萍, 等. 级联型逆变器的统一SVPWM方法[J]. 电工技术学报, 2014, 29(6): 145-152. Yang Xiaodong, Wang Chonglin, Shi Liping, et al.Generalized space vector PWM method for cascaded multilevel inverters[J]. Transactions of China Electrotechnical Society, 2014, 29(6): 145-152. [10] Angulo M, Lezana P, Kouro S, et al.Level-shifted PWM for cascaded multilevel inverters with even power distribution[C]//Proceedings of 2007 IEEE Power Electronics Specialists Conference (PESC), Orlando, FL, USA, 2007: 2373-2378. [11] Rodriguez J, Franquelo L G, Kouro S, et al.Multilevel converters: an enabling technology for high-power applications[J]. Proceedings of the IEEE, 2009, 97(11): 1786-1817. [12] McGrath B P, Holmes D G. Multicarrier PWM strategies for multilevel inverters[J]. IEEE Transa- ctions on Industrial Electronics, 2002, 49(4): 858-867. [13] Carrara G, Gardella S, Marchesoni M, et al.A new multilevel PWM method: a theoretical analysis[J]. IEEE Transactions on Power Electronics, 1992, 7(3): 497-505. [14] Omer P, Kumar J, Surjan B S.Comparison of multicarrier PWM techniques for cascaded H-bridge inverter[C]//Proceedings of 2014 IEEE Students' Conference on Electrical, Electronics and Computer Science (SCEECS), Bhopal, India, 2014: 1-6. [15] 王碧芳, 宫金武, 胡伟. 级联型多电平逆变器的改进PWM控制方法[J]. 电力系统自动化, 2006, 30(7): 73-75. Wang Bifang, Gong Jinwu, Hu Wei.Improved PWM control strategies for cascaded multilevel inverter[J]. Automation of Electric Power, 2006, 30(7): 73-75. [16] 李继华, 阮新波, 王学华. 级联型多电平逆变器线电压谐波优化的SVPWM策略[J]. 电工技术学报, 2014, 29(6): 120-128. Li Jihua, Ruan Xinbo, Wang Xuehua.A SVPWM strategy with optimal line-to-line voltage harmonic spectrum for cascaded multilevel inverters[J]. Transactions of China Electrotechnical Society, 2014, 29(6): 120-128. [17] 张兰勇, 曹岸, 刘胜. 级联多电平变换器的新型混合PWM技术[J]. 仪器仪表学报, 2016, 37(10): 2234-2242. Zhang Lanyong, Cao An, Liu Sheng.Novel hybrid PWM for cascaded multilevel converter[J]. Chinese Journal of Scientific Instrument, 2016, 37(10): 2234-2242. [18] 王立乔, 齐飞. 级联型多电平变流器新型载波相移 SPWM研究[J]. 中国电机工程学报, 2010, 30(3): 28-34. Wang Liqiao, Qi Fei.Novel carrier phase-shifted SPWM for cascade multilevel converter[J]. Pro- ceedings of the CSEE, 2010, 30(3): 28-34 .