Abstract：Direct current (DC) de-icing devices are essential equipment for ensuring the safe and stable operation of power grids in regions frequently affected by severe icing disasters, as they enable rapid removal of ice accretion on transmission lines. Among various de-icing technologies, the modular multilevel converter (MMC)-based DC de-icing system has emerged as a mainstream solution due to its advantages of compact capacity, high efficiency, flexible connection topology, and low reactive power demand. However, under existing DC current control schemes, such systems generally encounter prominent DC voltage fluctuation problems. These fluctuations may induce circulating current distortion in converter arms and capacitor voltage imbalance among submodules, which pose significant challenges to system stability and long-term reliability. To address these problems, this study systematically investigates the underlying mechanism of DC voltage fluctuation from a control system perspective. Firstly, through mathematical modeling and theoretical analysis, the fundamental cause of voltage fluctuation is identified. It is demonstrated that the observed DC voltage oscillations do not stem from control precision limitations, but are caused by the clamping effect of the current control loop on the modulation voltage. This clamping leads to frequent variations in the number of inserted submodules per phase, resulting in significant DC voltage disturbances. Secondly, based on the identified mechanism, a modified control strategy is proposed. The core idea combines modulation DC voltage rounding with adaptive switching of the DC current reference value. Specifically, the modulation voltage is constrained to integer multiples of the rated submodule capacitor voltage, stabilizing the submodule configuration. Simultaneously, the DC current reference value is adaptively adjusted according to the dynamic state of the system, thereby suppressing submodule switching fluctuations and improving DC voltage stability. Thirdly, to eliminate steady-state current deviations introduced by reference value switching, a real-time current state monitoring mechanism is further incorporated. This mechanism continuously detects and compensates for steady-state current errors, thereby enhancing current control accuracy and improving steady-state performance of the system. Finally, simulation studies verify that the proposed control strategy effectively suppresses DC voltage oscillations, mitigates arm circulating current distortion, and reduces capacitor voltage imbalance. As a result, both the dynamic performance and operational stability of the MMC-based DC de-icing system are significantly improved while still meeting the required de-icing current amplitude without additional hardware or complex modifications. In conclusion, this research clarifies that: (1) The inability to maintain the modulation DC voltage as integer multiples of submodule rated capacitor voltage under existing control schemes is the root cause of DC voltage fluctuation in MMC-based DC de-icing devices. (2) The proposed control strategy, integrating voltage rounding and adaptive reference adjustment, fundamentally suppresses configuration-induced voltage disturbances. The additional current state monitoring further refines steady-state current accuracy. The solution offers a practical approach for improving MMC de-icing system performance within existing hardware configurations, without the need for supplementary filtering equipment or hardware redesign.
闫旭, 何佳伟, 李斌, 周博昊, 孙强, 王文博. MMC型直流融冰系统直流电压波动机理分析及抑制方法[J]. 电工技术学报, 2026, 41(7): 2208-2222.
Yan Xu, He Jiawei, Li Bin, Zhou Bohao, Sun Qiang, Wang Wenbo. DC Voltage Fluctuation Mechanism and Suppression Methods in MMC-Based DC De-Icing System. Transactions of China Electrotechnical Society, 2026, 41(7): 2208-2222.
[1] 黄亚飞, 陈阳宁, 杨鑫, 等. 基于遮蔽效应分析的分裂导线覆冰特性及快速计算方法[J]. 电工技术学报, 2025, 40(9): 2852-2863. Huang Yafei, Chen Yangning, Yang Xin, et al.Icing characteristics and rapid calculating method of bundled conductor of transmission line based on shadowing effect analysis[J]. Transactions of China Electrotechnical Society, 2025, 40(9): 2852-2863. [2] 杨国林, 蒋兴良, 廖乙, 等. 输电线路单导线自由扭转覆冰动态仿真研究[J]. 电工技术学报, 2024, 39(13): 4079-4089. Yang Guolin, Jiang Xingliang, Liao Yi, et al.Simulation study of the free torsional icing on single conductors of transmission lines[J]. Transactions of China Electrotechnical Society, 2024, 39(13): 4079-4089. [3] 胡琴, 王欢, 舒立春, 等. 覆冰条件下风力发电机叶片防/除冰方法综述[J]. 电工技术学报, 2024, 39(17): 5482-5496. Hu Qin, Wang Huan, Shu Lichun, et al.Review of anti-/de-icing methods for wind turbine blades under icing conditions[J]. Transactions of China Electro- technical Society, 2024, 39(17): 5482-5496. [4] Wang Juanjuan, Fu Chuang, Chen Yiping, et al.Research and application of DC de-icing technology in China southern power grid[J]. IEEE Transactions on Power Delivery, 2012, 27(3): 1234-1242. [5] 许逵, 马晓红, 邴钰淇, 等. 电压源和电流源混合型融冰技术及其控制策略[J]. 高电压技术, 2020, 46(8): 2789-2798. Xu Kui, Ma Xiaohong, Bing Yuqi, et al.VSC and CSC hybrid de-icing technology and its control strategy[J]. High Voltage Engineering, 2020, 46(8): 2789-2798. [6] Li Binbin, Shi Shaolei, Xu Dianguo, et al.Control and analysis of the modular multilevel DC de-icer with STATCOM functionality[J]. IEEE Transactions on Industrial Electronics, 2016, 63(9): 5465-5476. [7] 郭裕群, 周月宾, 许建中, 等. 适用于全桥型模块化多电平换流器的直流融冰装置控制策略[J]. 电力系统自动化, 2017, 41(5): 106-113. Guo Yuqun, Zhou Yuebin, Xu Jianzhong, et al.Control strategies of DC ice-melting equipments for full-bridge modular multilevel converters[J]. Automation of Electric Power Systems, 2017, 41(5): 106-113. [8] 班国邦, 牛唯, 杨旗, 等. 模块化多电平直流融冰装置谐振机理及抑制措施研究[J]. 电力系统保护与控制, 2022, 50(3): 180-187. Ban Guobang, Niu Wei, Yang Qi, et al.The resonance mechanism and suppression measures of DC ice-melting equipment based on a modular multilevel converter[J]. Power System Protection and Control, 2022, 50(3): 180-187. [9] 李政林. 基于全桥MMC拓扑结构的直流融冰装置工程应用研究[J]. 电力勘测设计, 2024(8): 79-83. Li Zhenglin.Research on engineering application of DC ice-melting device with full bridge MMC topology structure[J]. Electric Power Survey & Design, 2024(8): 79-83. [10] Lin Weixing, Jovcic D, Nguefeu S, et al.Full-bridge MMC converter optimal design to HVDC operational requirements[J]. IEEE Transactions on Power Delivery, 2016, 31(3): 1342-1350. [11] Hu Pengfei, Liang Yiqiao, Du Yi, et al.Development and testing of a 10 kV 1.5 kA mobile DC de-icer based on modular multilevel converter with STATCOM function[J]. Journal of Electronics, 2018, 18(2): 456-466. [12] 杨国林, 蒋兴良, 王茂政, 等. 输电线路单导线覆冰形状对直流大电流融冰时间的影响[J]. 电工技术学报, 2024, 39(9): 2916-2924. Yang Guolin, Jiang Xingliang, Wang Maozheng, et al.The impact of ice accumulation shape on the DC high current ice-melting time for a single conductor on power transmission line[J]. Transactions of China Electrotechnical Society, 2024, 39(9): 2916-2924. [13] 许逵, 马晓红, 饶崇林, 等. 全桥MMC型和晶闸管整流型直流融冰技术的研究与比较[J]. 南方电网技术, 2020, 14(4): 45-53. Xu Kui, Ma Xiaohong, Rao Chonglin, et al.Research and comparison of DC deicing technologies based on full bridge MMC and thyristor rectifier[J]. Southern Power System Technology, 2020, 14(4): 45-53. [14] 张夏辉, 韩民晓, 杨景刚, 等. 直流侧电压波动对MMC的环流影响机理分析及抑制方法[J]. 电力系统自动化, 2021, 45(15): 122-131. Zhang Xiahui, Han Minxiao, Yang Jinggang, et al.Analysis on influence mechanism of DC-side voltage fluctuation on circulating current of modular multilevel converter and its suppression method[J]. Automation of Electric Power Systems, 2021, 45(15): 122-131. [15] 潘子迅, 杨晓峰, 赵锐, 等. 不平衡电网下模块化多电平换流器的直流环流均衡策略[J]. 电工技术学报, 2024, 39(2): 541-553. Pan Zixun, Yang Xiaofeng, Zhao Rui, et al.DC circulating current balancing control of modular multilevel converter under unbalanced power grid[J]. Transactions of China Electrotechnical Society, 2024, 39(2): 541-553. [16] Moon J W, Kim C S, Park J W, et al.Circulating current control in MMC under the unbalanced voltage[J]. IEEE Transactions on Power Delivery, 2013, 28(3): 1952-1959. [17] 王强钢, 周亦尧, 廖建权, 等. 直流配电网电能质量研究综述[J]. 电力系统自动化, 2023, 47(7): 193-207. Wang Qianggang, Zhou Yiyao, Liao Jianquan, et al.Review on power quality in DC distribution network[J]. Automation of Electric Power Systems, 2023, 47(7): 193-207. [18] 胡顺全, 陈阿莲, 刘通, 等. 级联H桥储能变流器直流侧纹波电流协同抑制方法[J]. 电力系统自动化, 2024, 48(24): 136-144. Hu Shunquan, Chen Alian, Liu Tong, et al.Cooperative suppression method for DC-side ripple current in cascaded H-bridge energy storage converter[J]. Automation of Electric Power Systems, 2024, 48(24): 136-144. [19] 李霞林, 郭力, 黄迪, 等. 直流配电网运行控制关键技术研究综述[J]. 高电压技术, 2019, 45(10): 3039-3049. Li Xialin, Guo Li, Huang Di, et al.Research review on operation and control of DC distribution networks[J]. High Voltage Engineering, 2019, 45(10): 3039-3049. [20] 原亚雷, 钊翔坤, 徐高祥, 等. 兼顾电压波动抑制的级联H桥STATCOM相间电压平衡控制策略[J]. 电网技术, 2022, 46(4): 1494-1502. Yuan Yalei, Zhao Xiangkun, Xu Gaoxiang, et al.Clustered voltage balance control strategy of cascaded H-bridge STATCOM with suppressing DC voltage fluctuation[J]. Power System Technology, 2022, 46(4): 1494-1502. [21] 李梦杰, 谢震, 徐上, 等. 弱电网下构网型双馈风电机组直流动态分析及优化控制策略[J]. 电力系统自动化, 2024, 48(14): 129-138. Li Mengjie, Xie Zhen, Xu Shang, et al.DC-link dynamics analysis and optimal control strategy for grid-forming DFIG-based wind turbines in weak grid[J]. Automation of Electric Power Systems, 2024, 48(14): 129-138. [22] 薛英林, 徐政, 傅闯, 等. 500kV固定式直流融冰装置的静止无功补偿器重构方案[J]. 高电压技术, 2011, 37(12): 3135-3142. Xue Yinglin, Xu Zheng, Fu Chuang, et al.Static var compensator reconstruction scheme of 500 kV fixed DC de-icing device[J]. High Voltage Engineering, 2011, 37(12): 3135-3142. [23] 傅闯, 饶宏, 黎小林, 等. 直流融冰装置的研制与应用[J]. 电力系统自动化, 2009, 33(11): 53-56, 107. Fu Chuang, Rao Hong, Li Xiaolin, et al.Development and application of DC deicer[J]. Automation of Electric Power Systems, 2009, 33(11): 53-56, 107. [24] IEEE Power and Energy Society. IEEE guide for direct-current ice-melting technology of overhead transmission lines: IEEE Std 3133—2023[S]. New York: IEEE, 2023. [25] 吴小刚, 何锐. 全桥MMC型直流融冰装置关键参数及装置容量解耦分析研究[J]. 南方能源建设, 2023, 10(5): 72-79. Wu Xiaogang, He Rui.Research on the key parameters and device capacity decoupling analysis of full bridge MMC DC ice-melting device[J]. Southern Energy Construction, 2023, 10(5): 72-79. [26] 武鸿, 王跃, 刘熠, 等. 基于广义电容电压不平衡度的MMC子模块开路故障诊断策略[J]. 电工技术学报, 2023, 38(14): 3909-3922. Wu Hong, Wang Yue, Liu Yi, et al.Open circuit fault diagnosis strategy of MMC sub-module based on generalized capacitor voltage unbalance[J]. Transactions of China Electrotechnical Society, 2023, 38(14): 3909-3922.
2026, Vol. 41 
