CAJ | 학술논문

研究了由三个单相变压器组成的特高压三相变压器组的后备保护，提出了用阻抗纵联保护作为特高压大容量变压器相间短路的快速后备保护的方案。分析了采用超范围允许式和超范围闭锁式阻抗纵联保护方案的可行性和优越性。说明了阻抗保护受励磁涌流影响小的原理，并用数字仿真证明了此论断的正确性。建立了特高压变压器的仿真模型，仿真结果证明在变压器空投和外部故障切除时产生的励磁涌流不会使阻抗保护误动，而在变压器出口相间短路时能够快速切除故障。采用所提出的保护方案可提高特高压变压器保护的可靠性。
연구료유삼개단상변압기조성적특고압삼상변압기조적후비보호，제출료용조항종련보호작위특고압대용량변압기상간단로적쾌속후비보호적방안。분석료채용초범위윤허식화초범위폐쇄식조항종련보호방안적가행성화우월성。설명료조항보호수려자용류영향소적원리，병용수자방진증명료차론단적정학성。건립료특고압변압기적방진모형，방진결과증명재변압기공투화외부고장절제시산생적려자용류불회사조항보호오동，이재변압기출구상간단로시능구쾌속절제고장。채용소제출적보호방안가제고특고압변압기보호적가고성。
The backup protection of UHV large capacity transformers consisted of three single phase transformers is studied. The overreach permissive type and the overreach blocking type impedance pilot protection scheme, used as backup protection of these transformers is proposed. The feasibility and superiority of the proposed scheme are proved. Such impedance protections are less affected by magnetizing inrush currents and the correctness of the conclusion is testified by digital simulations. The simulation model of UHV transformer is established. Simulation results prove that the magnetizing inrush current caused by transformer no-load switching and external fault clearing will not make the impedance protection maloperation, while the fault can be cleared fast at interphase short-circuit of transformer exit. The proposed protection scheme can improve the reliability of protection of large capacity UHV transformers.