| 引用本文: | 吴禹承,宋强,赵晓斌,李峰,邹常跃,王彦峰,彭穗,冯俊杰,李政轩.基于辅助弱联络的海上风电多端异构直流送出系统[J].电力自动化设备,2025,45(12):23-32. |
| WU Yucheng,SONG Qiang,ZHAO Xiaobin,LI Feng,ZOU Changyue,WANG Yanfeng,PENG Sui,FENG Junjie,LI Zhengxuan.Multi-terminal heterogeneous DC transmission system for offshore wind power based on auxiliary weak contact line[J].Electric Power Automation Equipment,2025,45(12):23-32. |
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| 摘要: |
| 在海上风电直流送出系统中，二极管整流器(DR)相比于模块化多电平换流器(MMC)具有成本低与紧凑性高的优势，但也存在黑启动困难、不具备交流构网能力等问题。为了充分利用DR的优势，实现千万千瓦级海上风电集群化直流送出，提出了一种基于辅助弱联络的多端异构直流送出拓扑结构。在海上各端分别采用MMC与DR拓扑，并在MMC端与DR端之间设置小容量直流辅助弱联络线。通过辅助弱联络线可以从MMC端向DR端风电场传输小容量有功功率，解决DR端风电场的黑启动、近零功率运行等问题。提出了联络逆变器的Q/f型协同构网控制策略及基于最小联络功率的外环控制策略，可以使联络逆变器与海上风机协同构建海上交流电压和频率，并在黑启动、正常稳态、近零功率等多运行模式之间自适应平滑切换。仿真结果验证了所提拓扑方案和控制策略的可行性与有效性。 |
| 关键词: 海上风电 多端异构 二极管整流器 辅助联络 近零功率运行 构网控制 |
| DOI：10.16081/j.epae.202510003 |
| 分类号:P752;TM614 |
| 基金项目:智能电网国家科技重大专项(2025ZD0805300)；中国南方电网有限责任公司科技项目(ZBKJXM20232463) |
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| Multi-terminal heterogeneous DC transmission system for offshore wind power based on auxiliary weak contact line |
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WU Yucheng1, SONG Qiang1, ZHAO Xiaobin2, LI Feng3, ZOU Changyue2, WANG Yanfeng3, PENG Sui3, FENG Junjie2, LI Zhengxuan1
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1.Department of Electrical Engineering, Tsinghua University, Beijing 100084, China;2.State Key Laboratory of HVDC, Electric Power Research Institute of China Southern Power Grid, Guangzhou 510663, China;3.Planning and Research Center of Guangdong Power Grid Co.,Ltd.,Guangzhou 510000, China
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| Abstract: |
| In the DC transmission system for offshore wind power, the diode rectifier(DR) offers advantages in low cost and high compactness compared to the modular multilevel converter(MMC). However, it also faces challenges like difficulty in black-start and lack of AC grid-forming capability. In order to fully leverage the advantages of DR and achieve clustered DC transmission of offshore wind power at the tens of gigawatts level, a multi-terminal heterogeneous DC transmission topology structure based on auxiliary weak contact line is proposed. The MMC and DR topologies are employed at different offshore terminals, with a low-capacity DC auxiliary weak contact line established between the MMC and DR terminals. Through the auxiliary weak contact line, a low-capacity active power can be transmitted from the MMC terminal to the DR-side wind farm, addressing the black-start and near-zero power operation issues of the DR-side wind farm. The Q/f-type cooperative grid-forming control strategy for tie-inverter is proposed, along with the outer-loop minimum tie-power control strategy. This enables the tie-inverters and wind turbines to collaborate to establish the offshore AC voltage and frequency, and ensures adaptive and seamless switching among multiple operation modes, such as black-start, normal steady-state and near-zero power. The simulative results validate the feasibility and effectiveness of the proposed topology and control strategies. |
| Key words: offshore wind power multi-terminal heterogeneity diode rectifier auxiliary contact near-zero power operation grid-forming control |
