摘要
单端量后备保护对保证配电网安全运行具有重要的作用,但其整定工作任务繁重、难以自适应逆变类分布式电源随机接入的场景。因此,亟须研究无需逐级整定的后备保护自适应配合方案。针对故障稳态阶段高比例新能源接入后短路电流受限导致传统阶段式配合的保护存在误动/拒动的问题,提出“暂态故障识别+稳态动作判别”的接力式反时限后备保护方案。首先,定性分析并用阻抗特性验证拓扑结构变化时故障分量瞬时实功率的暂态特征分布,提取有自然差异的最小适用频带内的时域信息,计算换流器未调节阶段的暂态能量。其次,给出全网统一反时限特性方程的参数选取原则,实现相邻保护间的自适应配合;构造基于稳态电压的动作判据,得到利用故障全过程电气量的单端量后备保护配合方案。最后,仿真验证所提方法在不同拓扑、分布式电源容量以及接入方式变化时的有效性。
Single-end backup protection plays an important role in ensuring the safe operation of the distribution network.However,its setting task is heavy and it is difficult to adapt to the scenario of the random access of inverter-interfaced distributed generation(IIDG).Therefore,it is urgent to study an adaptive coordination scheme for backup protection that does not require step-by-step setting.A relay-type inverse-time backup protection scheme with“transient fault identification+steady-state operation discrimination”is proposed to address the issue of mal-operation/miss-operation in traditional stage coordination protection due to the limited short-circuit current during the steady-state stage of faults after the high proportion of renewable energy is connected.Firstly,the qualitative analysis is conducted and impedance characteristics are used to verify the transient characteristic distribution of the instantaneous real power of the fault component when the topology changes.Time-domain information within the minimum applicable frequency band with natural differences is extracted,and the transient energy of the unregulated phase of the converter is calculated.Secondly,the parameter selection principle for the unified inverse-time characteristic equation of the entire network is given to achieve the adaptive coordination between adjacent protections.Then,an action criterion based on steady-state voltage is constructed,and a single-end backup protection coordination scheme is obtained using the electrical quantities throughout the fault process.Finally,the simulation verifies the effectiveness of the proposed method with different topologies,distributed power capacity,and changes in accessing modes.
作者
常娜娜
宋国兵
常仲学
张晨浩
郑玉平
吴通华
CHANG Nana;SONG Guobing;CHANG Zhongxue;ZHANG Chenhao;ZHENG Yuping;WU Tonghua(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211106,China;State Key Laboratory of Technology and Equipment for Defense against Power System Operational Risks,Nanjing 211106,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2023年第24期143-155,共13页
Automation of Electric Power Systems
基金
国家电网公司科技项目(5108-202240278A-2-0-XG)。
关键词
后备保护
分布式电源
暂态
稳态
最小适用频带
反时限特性
自适应配合
backup protection
distributed generator
transient
steady-state
minimum applicable frequency band
inverse-time characteristic
adaptive coordination
