ZHOU Yuyan,LIU Shenquan,JIANG Shaoyan,et al.Power balancing strategy for M3C arm power in interconnected partitioned grids based on third-harmonic injection[J].ZHEJIANG ELECTRIC POWER,2026,45(07):104-112. DOI: 10.19585/j.zjdl.202607010.
ZHOU Yuyan,LIU Shenquan,JIANG Shaoyan,et al.Power balancing strategy for M3C arm power in interconnected partitioned grids based on third-harmonic injection[J].ZHEJIANG ELECTRIC POWER,2026,45(07):104-112. DOI: 10.19585/j.zjdl.202607010.DOI:
Power balancing strategy for M3C arm power in interconnected partitioned grids based on third-harmonic injection
ion of partitioned power grids where the input and output frequencies of the modular multilevel matrix converter (M
3
C) are identical, the coupling between the voltages and currents on both sides introduces an additional DC component into the arm power. This results in an arm power imbalance that must be mitigated. First, the generation mechanism and characteristics of this imbalance are analyzed, demonstrating that conventional balancing strategies based on fundamental-frequency circulating current injection become ineffective when the voltage magnitudes on both sides are comparable. Subsequently, a control strategy is proposed based on the injection of a third-harmonic arm common-mode voltage and circulating current. Subject to the constraint of not increasing the peak arm voltage, a method for selecting the optimal amplitude and phase of the third-harmonic common-mode voltage is derived. Furthermore, the relationship between the circulating current amplitude and the voltage transformation ratio and power factor is investigated. Finally, the effectiveness of the proposed strategy is validated through MATLAB/Simulink simulations.
Zhou Baorong , Hong Chao , Jin Xiaoming , et al . Study of backbone structure change from synchronous to asynchronous in China southern power grid [J]. Proceedings of the CSEE , 2016 , 36 ( 8 ): 2084 - 2092 .
Lin Yong , Chen Yunpeng , Wang Zhiyong , et al . Demonstration and suggestion on network scheme of Guangdong power system [J]. Southern Power System Technology , 2020 , 14 ( 3 ): 42 - 48 .
Tang Xiaojun , Han Minxiao , Xie Yan , et al . Capacity and siting configuration method of VSC-HVDC applied to urban power grid partition interconnection [J]. Power System Technology , 2019 , 43 ( 5 ): 1709 - 1716 .
Yu Ting , Pu Tianjiao , Liu Guangyi , et al . Reactive power and voltage control strategy of receiving-end urban power grid with flexible DC interconnected between partitions [J]. High Voltage Engineering , 2017 , 43 ( 7 ): 2140 - 2145 .
Cai Hui , Peng Zhuyi , Qi Wanchun , et al . Study on application of back-to-back flexible direct current transmission technology in central urban grid [J]. Power Capacitor & Reactive Power Compensation , 2021 , 42 ( 2 ): 79 - 84 .
Yang Yan , Jin Chu , Cheng Xin , et al . Flexible DC interconnection scheme based on the outer ring of Guangdong-Hong Kong-Macao greater bay area [J]. Southern Power System Technology , 2021 , 15 ( 3 ): 15 - 21 .
Fang Dongping , Qiu Yang , Cui Jindong , et al . An optimal loss-reduction control strategy for MMC considering capacitor voltage ripple suppression [J]. Zhejiang Electric Power , 2025 , 44 ( 7 ): 82 - 92 .
Liu S Q , Wang X F , Ning L H , et al . Integrating offshore wind power via fractional frequency transmission system [J]. IEEE Transactions on Power Delivery , 2017 , 32 ( 3 ): 1253 - 1261 .
Li Jing , Wang Gang , Liu Shenquan , et al . Dynamic phasor modeling method for modular multilevel matrix converter considering the double-fundamental-frequency electrical coupling characteristics [J]. High Voltage Engineering , 2023 , 49 ( 9 ): 3774 - 3783 .
Ni Xiaojun , Ding Chao , Tang Yingjie , et al . Research on high-frequency resonance in flexible low-frequency AC transmission systems [J]. Zhejiang Electric Power , 2025 , 44 ( 6 ): 109 - 117 .
Li Shuyu , Yu Hongyang , Ge Jing , et al . Analysis of capacitance and voltage fluctuation characteristics of two-port matrix converter under power/low frequency interconnection [J]. Power System Technology , 2020 , 44 ( 4 ): 1437 - 1444 .
Cheng Qiming , Zhang Liang , Qu Bogang , et al . Dual-frequency circulating current injection-based arm voltage balancing control strategy for M3C in offshore wind power applications [J]. Smart Power , 2025 , 53 ( 5 ): 73 - 81 .
Li Jingzheng , Du Xiaotong , Li Meng . Single-ended protection scheme for offshore flexible low-frequency transmission lines based on high-frequency transient quantities [J]. Electric Power Construction , 2025 , 46 ( 8 ): 105 - 115 .
Han Huachun , Ning Lianhui , Li Chenchen , et al . Virtual synchronous generator control strategy of M3C converter in fractional frequency offshore wind power system [J]. Jiangsu Electrical Engineering , 2024 , 43 ( 6 ): 78 - 87 .
Wu Xiaodan , Li Jianchun , Dong Yunlong , et al . Comprehensive decoupling control strategy for modular multilevel matrix converter for low frequency offshore wind power transmission [J]. Proceedings of the CSEE , 2023 , 43 ( 8 ): 3177 - 3190 .
Fan B R , Wang K , Wheeler P , et al . A branch current reallocation based energy balancing strategy for the modular multilevel matrix converter operating around equal frequency [J]. IEEE Transactions on Power Electronics , 2018 , 33 ( 2 ): 1105 - 1117 .
Kawamura W , Hagiwara M , Akagi H . A broad range of frequency control for the modular multilevel cascade converter based on triple-star bridge-cells (MMCC-TSBC) [C]// 2013 IEEE Energy Conversion Congress and Exposition . September 15-19,2013 , Denver,CO,USA.IEEE , 2013 : 4014 - 4021 .
Urrutia M , Cárdenas R , Clare J C , et al . Continuous set model predictive control for energy management of modular multilevel matrix converters [J]. IEEE Transactions on Power Electronics , 2022 , 37 ( 5 ): 5731 - 5748 .
Cuzmar R , Montenegro A , Mora A , et al . Constrained MPC for intercluster energy control of modular multilevel matrix converters [J]. IEEE Transactions on Industrial Electronics , 2024 , 71 ( 7 ): 7766 - 7776 .
Kawamura W , Chiba Y , Hagiwara M , et al . Experimental verification of an electrical drive fed by a modular multilevel TSBC converter when the motor frequency gets closer or equal to the supply frequency [J]. IEEE Transactions on Industry Applications , 2017 , 53 ( 3 ): 2297 - 2306 .
Diaz M , Cardenas R , Espinoza M , et al . Vector control of a modular multilevel matrix converter operating over the full output-frequency range [J]. IEEE Transactions on Industrial Electronics , 2019 , 66 ( 7 ): 5102 - 5114 .
Yue S X , Ji Y , Wang Q Y , et al . Closed-loop decoupled control and implementation of the modular multilevel matrix converter in similar/equal frequency operation [C]// 2020 IEEE 9th International Power Electronics and Motion Control Conference (IPEMC2020-ECCE Asia) . November 29-December 2 , 2020 .Nanjing, China . IEEE ,2020: 3385 - 3390 .