| 引用本文: | 彭茂兰,唐金昆.伪双极MMC-HVDC系统联接变阀侧中性点电阻参数设计[J].电力自动化设备,2017,37(4): |
| PENG Maolan,TANG Jinkun.Design of valve-side neutral-point resistor for connection transformer of MMC-HVDC transmission system[J].Electric Power Automation Equipment,2017,37(4): |
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| 摘要: |
| 针对模块化多电平换流器高压直流输电MMC-HVDC(Modular Multilevel Converter based HVDC)直流单极接地故障暂态特性研究，提出了联接变阀侧中性点经电阻接地的伪双极MMC-HVDC系统发生直流单极接地故障时换流器电容放电的简化模型。将与故障极相连的三相桥臂电容放电回路等效为3个独立的RLC二阶零输入放电回路，从而简化了换流器电容放电与中性点故障电流的分析过程。基于简化模型分析得到的桥臂故障时刻导通子模块电容电压与中性点故障电流计算公式，研究了联接变阀侧中性点电阻参数设计与电容电压放电水平及控制保护系统闭锁换流器延时时间的配合关系，提出了中性点电阻的参数设计原则。最后，针对鲁西背靠背异步联网工程，在搭建的控制保护系统与RT-Lab形成的硬件闭环系统功能性试验平台上，验证了所提联接变阀侧中性点电阻参数设计原则的有效性。 |
| 关键词: 高压直流输电 模块化多电平换流器 直流单极接地故障 暂态分析 中性点电阻 参数设计原则 |
| DOI：10.16081/j.issn.1006-6047.2017.04.033 |
| 分类号:TM72 |
| 基金项目: |
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| Design of valve-side neutral-point resistor for connection transformer of MMC-HVDC transmission system |
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PENG Maolan, TANG Jinkun
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Maintenance & Test Center of Extra High Voltage Power Transmission Company of China Southern Power Grid Co.,Ltd.,Guangzhou 510663, China
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| Abstract: |
| For researching the transient characteristics, a simplified model of converter capacitor discharging during a monopolar DC grounding fault of the pseudo-bipolar MMC-HVDC(Modular Multilevel Converter based HVDC) is proposed, where the valve-side neutral-point of its connection transformer is grounded via a resistor. The discharging circuits of the three-phase arm capacitors connecting with the faulty pole are considered as three independent RLC second-order discharging circuits without input to simplify the analysis of converter capacitor discharging process and neutral-point fault current. Based on the formula deduced by the analysis for calculating the capacitor voltage and neutral-point current during the fault, the coordination among the capacitor discharging level, the delay time for blocking the converter by the control & protection system and the valve-side neutral-point resistor of the connection transformer is investigated, and the principle for designing the neutral-point resistor is proposed. Taking the Luxi back-to-back HVDC project as an example, the effectiveness of the proposed design principle is verified on a HIL(Hardware In Loop) functional test platform consisting of the control & protection system and the real-time digital simulator RT-Lab. |
| Key words: HVDC power transmission MMC monopolar DC grounding fault transient analysis neutral point resistance parameter design principle |
