分类号 TM772 密级 UDC 学号 3107161027 5Yn/接线变压器零序纵差接线变压器零序纵差 保护原理的研究保护原理的研究学位申请人 ： 张军民 指 导 教 师： 索南加乐 教授 学 科 专 业： 电气工程 学 位 类 别： 工 学 西安交通大学硕士学位论文西安交通大学硕士学位论文 Yn/接线变压器零序纵差保护原理的研究接线变压器零序纵差保护原理的研究 张军民张军民 2010 年年 6 月月西安交通大学硕士学位论文西安交通大学硕士学位论文 Yn/接线变压器零序纵差保护原理的研究接线变压器零序纵差保护原理的研究 张军民张军民 2010 年年 6 月月2010 年 6 月硕士学位论文Yn/接线变压器零序纵差保护原理的研究接线变压器零序纵差保护原理的研究申请人：张军民学科专业：电气工程指导教师：索南加乐教授2010 年 6 月Study of Zero-Sequence Current Differential Protection for Transformer with Y-Delta ConnectionA thesis submitted toXian Jiaotong Universityin partial fulfillment of the requirementfor the degree ofMaster of Engineering ScienceByZhang Junmin (Electrical Engineering) Supervisor: Prof. Suonan JialeJune 2010摘要I论文题目：论文题目：Yn/接线变压器零序纵差保护原理的研究接线变压器零序纵差保护原理的研究学科专业：电力系统及其自动化学科专业：电力系统及其自动化申申请请人人 ：张军民：张军民指导教师：索南加乐教授指导教师：索南加乐教授摘 要作为电力系统中重要的电气主设备之一，变压器在整个电力系统中的地位不言而喻，其是否能够安全运行也将直接影响着电力系统的安全运行。随着电力系统的发展，变压器容量越来越大、电压等级越来越高、造价越来越贵，如果变压器保护不能快速而可靠的动作，在故障时，必将带来经济上的重大损失。因此，现代电力系统对电力变压器保护提出了很高的要求，研究和探索动作速度快、可靠性和灵敏性高的变压器保护新原理就显得十分必要。1本文以提高变压器保护性能为目标，以 Yn/接线变压器为研究对象，提出了基于零序电流差动原理的变压器保护方案，以变压器各侧零序电流构成零序电流纵差保护。针对目前 Yn/变压器在典型的电流互感器配置方案下 侧绕组零序电流无法测量的情况，本文通过零序等值电路计算得到 侧绕组中的零序环流。由于零差保护是基于故障分量的纵差保护原理，制动电流中去掉了负荷电流的影响，对于轻微匝间短路故障，零序差动保护较常规差动保护灵敏度更高。另外，保护能够可靠区分区内外故障，且在绕组内部发生单相接地短路时灵敏度不会降低。文中对 TA 饱和以及励磁涌流对零序差动保护的影响进行了理论分析，结果表明零序差动保护受 TA 饱和影响较大，而受励磁涌流的影响较小，不会由于励磁涌流的影响而产生误动。PSCAD 仿真以及动模数据均验证了零序电流差动保护的可靠性和灵敏度。通过变压器各种故障情况下零序纵差保护和传统保护性能的比较表明：零序电流纵差保护在外部故障时可靠不动作，在单相接地和小匝间短路时可靠动作，灵敏度较常规差动保护更高。另外仿真了励磁涌流情况下零序差动保护的动作情况，结果表明，零差保护不会由于励磁涌流而误动。关关 键键 词词：变压器保护；Y-Delta 绕组；零序电流纵差保护；励磁涌流论文类型论文类型：应用研究1 本研究得到国家自然科学基金(编号：50907048，编号：50677051)资助。西安交通大学硕士学位论文IITitle: Study of Zero-Sequence Current Differential Protection for Transformer with Y-Delta Connection Speciality:Electrical Engineering Applicant:Zhang Junmin Supervisor:Prof. Suonan JialeABSTRACTAs one of the major electric apparatuses in power system, transformer plays an important role in power transmission system. If fault occurs during operation, the security and stability of power system would be greatly affected. With the development of modern power system, large capacity EHV/UHV transformers have evolved to meet the increasing need of power system. On one hand, modern transformers are vital and expensive. On the other hand, if modern transformers were damaged by faults, it would need a long time and great effort to repair them, for which, great economic benefits would be lost. Considering the serious consequence caused by faults in transformer, the researches for new transformer protection scheme with high performance, such as speed, reliability and sensibility, is in demand.2In order to increase performance of transformer protection , based on the transformer with Yn/ connection, a differential protection method based on zero-sequence current is proposed in this paper. The protection scheme is constructed by using the zero-sequence current of each sides.Though the zero-sequence current of the side can not be measured under the typical configuration of TA, we can calculate the zero-sequence current in the Delta side by the zero-sequence equivalent circuit. As the zero-sequence differential protection is based on fault component , the load currents is removed from the restrain current. So the zero-sequence differential protection has the higher sensitive to earthing fault and small inter-turn fault.To analysis the Influence of TA saturation and inrush current on zero-sequence differential protection, the results show that the Influence of TA saturation on zero-sequence differential is obvious, while less affected by the inrush current. The protection will not misoperate because of the inrush current. The simulation results using PSCAD/EMTDC and the dynamic simulation datas verifies the reliability and sensitivity of Zero-sequence current differential protection. Through the transformer under various fault conditions and zero-sequence differential protection 2These works are supported by the National Natural Science Foundation of China(No: 50907048, NO: 50677051).ABSTRACTIIIperformance comparison shows that the traditional protection: zero sequence current differential protection is not reliable in the external fault movement, in the single-phase earth and small turn to turn short-circuit action when the reliable and sensitive than conventional higher differential protection. Another simulation of the inrush current under zero-sequence differential protection cases, the results indicate that the zero differential protection will not malfunction because the inrush current.KEY WORDS: Transformer Protection；Y-Delta Connection；Zero-sequence Current Differential Protection；Inrush Current TYPE OF THESIS: Application Research西安交通大学硕士学位论文IV目 录1 绪论.