变电所主变压器继电保护.doc

变电所主变压器继电保护
摘要:变压器是电力系统的重要组成部分。它的正常与否直接关系到电力系统的安全和经济运行。本次设计是变压器继电保护的初步设计。根据短路计算的结果,选择了短路器,隔离开关,母线电气设备。
为了保护变压器内部和引出线套管的故障,选择了纵联差动保护作为变压器的主保护。影响差动保护可靠性是电路中由于各种原因产生的不平衡电流。通过计算,选择躲过外部短路时产生的最大不平衡电流作为纵联差动保护的动作电流。本设计还选择了***保护作为变压器油箱内发生故障时的主保护。定时限过电流保护作为变压器纵联差动保护的后备保护。本设计要保护的变压器是处在中性点直接接地的电力系统中,所以采用零序过电流作为变压器接地的后备保护。在本次设计中,我还选择了过负荷保护作为变压器的后备保护并对以上保护进行了整定。
关键词: 变压器差动保护***保护励磁涌流
The Relay of Main Transformer in Substation
hujianbin
College: Information Engineering College Class: Electric 04-2 NO.:200440509208
Abstract: Transformer is an important part of power system. It's normal or not directly related to the power system of security and economic operations. The design is the preliminary design of transformer relay. According to short-circuit calculation, we are choice of short-circuit, isolating switch, bus and other electrical equipment.
In order to protect the internal transformer and draws out line drive pipe casing failures and chose a pilot differential protection as the main transformer protection. The influence differential motion protection reliability is in an electric circuit, because each kind of reason produces circulating current. Through putation, the choices of external short-circuit the largest imbalance in the current longitudinal differential protection as the current action. This design also chosen to protect the gas tank as a transformer in the failure of th