【作者】 郑晓冬；

【导师】 邰能灵；

【作者基本信息】 上海交通大学 ， 电力系统及其自动化， 2013， 博士

【摘要】 特高压直流输电线路是电力系统的大动脉，肩负着能源产地与用电中心区域之间输送电能的重任。高性能的特高压直流输电线路保护可及时发现线路故障，是直流系统及与之相连的交流系统安全运行的重要保证。因此，提高特高压直流输电线路继电保护的性能，对提高电力系统的安全性具有重要作用。本文对特高压直流输电线路故障响应特性与保护新方法进行了研究，主要研究内容包括：（1）建立特高压直流输电系统的数值仿真模型，对特高压直流输电系统模型中的核心组件及参数配置进行详细分析、设计，测试结果验证了模型的可靠性。（2）分析了长距离特高压直流输电线路故障条件下分布电容电流的特点以及对差动保护的影响，提出了考虑分布电容电流补偿的直流差动保护。通过对比补偿分布电容电流前后差动保护的性能，证明经补偿后的直流差动保护的可靠性和灵敏度得到明显提高。（3）针对传统差动保护应用在特高压直流输电线路上遇到的不平衡电流引起的保护区外故障误动和区内故障拒动的问题，本文提出新型特高压直流输电线路差动保护方案。该方案基于直流输电线路参数，进行并联分支修正，消除暂态谐波电流的影响，有效提高了直流差动保护的可靠性和灵敏度。（4）分析了直流线路参数与特高压直流输电线路两端暂态能量增量的关联，总结出不同故障情况下线路两端暂态能量增量的特点。在此基础上，提出特高压直流输电线路暂态能量保护方案，该方案不仅可以准确、快速的区分区内与区外故障，也有很好的耐受过渡电阻能力。（5）依据特高压直流输电线路的边界特性，分析不同故障情况下特高压直流输电线路两端特征谐波电流的特点，结果显示内部故障存在连续特征谐波。提出特高压直流输电特征谐波保护方案，探讨了故障电阻和故障位置两个因素对本方案的影响。（6）VSC-HVDC是一种更为灵活的直流输电方式，能够实现有功和无功的独立解耦控制。分析了不同故障条件下VSC-HVDC输电线路两端的载波频率谐波电流响应特点，提出VSC-HVDC输电线路的载波频率保护方案，该保护方案可以正确的判定区内、外故障类型。（7）利用特高压直流现场录波数据和RTDS系统对本文的特高压直流输电线路保护方案进行了测试。测试结果表明本文所提保护均能正确动作。更多还原

【Abstract】 Ultra High Voltage Direct Current (UHVDC) transmission line is main backbone ofpower system, the important mission of UHVDC transmission line is the electric energytransmission from the source of energy to the power load center. The high performanceprotection scheme for UHVDC transmission line can detect line faults quickly, itguarantees safety operation of the UHVDC system and the adjacent ac system. So theUHVDC transmission line protection has the important role in the security of the powersystem.The dissertation focuses on the response features of UHVDC transmission line faultsand novel protection schemes for UHVDC transmission line. The main contributions areas follows:(1) The UHVDC numerical simulation model is presented in this dissertation and thedetailed structures and parameter configuration of the UHVDC transmission system modelare also introduced comprehensively, the reliability of the UHVDC transmission systemmodel is verified.(2) The effect of long distance UHVDC transmission line on differential protection isanalyzed and an improved differential protection scheme with distributed capacitivecurrent compensation is proposed. Comparing the performances of differential protectionwith/without distributed capacitive current compensation, the result shows that thereliability and sensitivity of DC differential protection are effectively improved withdistributed capacitive current compensation.(3) Two problems facing traditional differential protection for UHVDC transmissionline: the misoperation under external faults and the refuse operation under internal faults.In the dissertation, a novel differential protection scheme for UHVDC transmission line ispresented. With parameters of DC transmission line, the shunt branches are corrected andthe harmonic currents are removed, the reliability and sensitivity of DC differentialprotection are effectively improved.(4) The relation between the parameters of DC transmission line and the variation of transient energy at two terminals of the UHVDC transmission line are analyzed and theresponses of the variation of transient energy under different faults are investigated. Atransient energy protection scheme for UHVDC transmission line is proposed. It can notonly identify internal fault and external fault correctly and quickly, but also can responseto the high ground resistance fault.(5) Based on the boundary characteristic of the UHVDC transmission line, theresponses of characteristic harmonic currents at two terminals of the UHVDCtransmission line are analyzed under various faults. The periodic characteristic harmoniccan be detected under internal fault. According to that, a new characteristic harmoniccurrent protection scheme is proposed and the influence on the performance of theproposed protection by two factors including fault resistance and fault location is alsodiscussed.(6) VSC-based HVDC is a more flexible HVDC transmission mode, the active powerand reactive power can be decoupled and controlled independently in VSC-HVDCtransmission system. The responses of the first carrier frequency harmonic current at twoterminals of VSC-Based HVDC transmission line are analyzed under various faults. Acarrier frequency protection scheme for VSC-Based HVDC transmission line is proposed.By the protection scheme, the internal fault and external fault can be identified correctly.(7) The RTDS system and fault recorder data from UHVDC converter substation areemployed to verify the proposed protection schemes. The presented protection schemescan trip correctly under internal faults, so the proposed protection schemes in thisdissertation are reliable and feasible.更多还原