【摘要】 海上风电低频输电线路故障后，其双侧换流器的控制策略将会影响故障特征，这使得传统电流差动保护将面临灵敏度下降甚至拒动的风险.针对这一问题，首先基于参数识别的思想，分析低频线路发生区内、区外故障时的拓扑的差异.其次对电容模型误差进行改进，将改进后的电容模型和阻感模型进行对比，构建了利用综合模型误差的纵联保护方案.最后，在PSCAD/EMTDC中搭建海上风电低频输电系统模型，对保护方案进行验证.仿真结果表明：所提方案能够快速、可靠地识别出故障，具有良好的耐过渡电阻、抗噪声和抗干扰能力，且受换流器控制策略及采样频率影响较小.更多还原

【Abstract】 When the low-frequency transmission line of offshore wind power fails, the control strategy of its double-side converter affects the fault characteristics, which makes the traditional current differential protection face the risk of sensitivity decline or rejection. To solve this problem, firstly, based on parameter identification, the topological differences of the low-frequency line during the occurrence of internal and external faults are analyzed. Secondly, the capacitance model error is improved, the improved capacitance model is compared with the resistance model, and the pilot protection scheme using the comprehensive model error is constructed. Finally, the lowfrequency transmission system model of offshore wind power is built in PSCAD/EMTDC to verify the protection scheme. Simulation results show that the proposed scheme can identify faults quickly and reliably, has good transition resistance, anti-noise, and anti-interference capabilities, and is less affected by converter control strategy and sampling frequency.更多还原