| 引用本文: | 秦小华,侯俊杰,樊艳芳,等.柔性直流电网双端量自适应限流控制策略研究[J].电力系统保护与控制,2025,53(8):81-95.[点击复制] |
| QIN Xiaohua, HOU Junjie, FAN Yanfang,et al.Research on two-terminal adaptive current limiting control strategy for flexible HVDC grids[J].Power System Protection and Control,2025,53(8):81-95[点击复制] |
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| 摘要: |
| 柔性直流电网中模块化多电平换流器(modular multilevel converters, MMC)限流控制策略能有效降低对线路保护速动性的要求以及直流断路器(DC circuit breakers, DCCB)的开断容量，但易造成非故障端功率传输中断，扩大故障影响范围。为进一步提高其选择性，提出了一种双端量自适应限流控制策略。首先，根据限流控制的选择性原则及目的确定MMC自适应限流控制策略的启动范围。其次，根据限流启动范围内、外线路两端的初始电流行波极性确定故障区域，实现自适应限流控制策略的选择性启动，并根据故障后线路电压的跌落程度自适应地重构直流阻抗，抑制故障电流。最后，形成自适应限流控制、故障区域识别与故障隔离三者紧密融合的整体方案。仿真结果表明，所提自适应限流控制策略在降低DCCB技术需求的同时具有良好的选择性，并对故障类型、过渡电阻和噪声均有一定的适应性。 |
| 关键词: 柔性直流电网 限流策略 自适应 双端 故障识别 |
| DOI：10.19783/j.cnki.pspc.240522 |
| 投稿时间：2024-04-29修订日期：2024-08-25 |
| 基金项目:国家重点研发计划项目资助(2021YFB1507000)；国家自然科学基金项目资助(52442705)；新疆维吾尔自治区自然科学基金项目资助(2022D01C662)；“天池英才”引进计划项目资助；新疆维吾尔自治区研究生科研创新项目资助(XJ2024G045) |
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| Research on two-terminal adaptive current limiting control strategy for flexible HVDC grids |
| QIN Xiaohua1,HOU Junjie1,FAN Yanfang1,SONG Guobing1,2,SUN Yao1,WU Xiaofang3 |
| (1. School of Electrical Engineering, Xinjiang University, Urumqi 830046, China; 2. School of Electrical Engineering,
Xi’an Jiaotong University, Xi’an 711049, China; 3. Electric Power Research Institute of State Grid
Xinjiang Electric Power Co., Ltd., Urumqi 830011, China) |
| Abstract: |
| The current limiting control strategy for modular multilevel converters (MMC) in flexible HVDC power grids can effectively reduce the requirements for line protection speed and the breaking capacity of DC circuit breakers (DCCB). However, it may cause power transmission interruption at the non-fault terminals, thus expanding the fault impact area. To further improve its selectivity, a two-terminal adaptive current limiting control (ACLC) strategy is proposed. First, the starting range of the ACLC for MMC based on the selectivity principle and purpose of current limiting control is determined. Then, based on the initial current traveling wave polarity at both ends of the line within and outside the current limiting starting range, the fault area is identified, allowing the selective activation of the ACLC strategy. Additionally, the DC impedance is adaptively reconstructed based on the degree of voltage drop in the line after fault to suppress the fault current. Finally, an integrated scheme is formed by closing combining ACLC, fault area identification, and fault isolation. Simulation results show that the proposed ACLC strategy has good selectivity, reduces DCCB technical requirements, and exhibits certain degree of adaptability to fault types, fault resistance, and noise. |
| Key words: flexible HVDC power grid current limiting strategy adaptability two-terminal fault identification |
