The fault of electrical transmission lines and function relay protection & automation

Abstract

We are introducing some ideas regarding classification the faults and InjUreS that are registered on the operator note in the Central Region's Electrical network in 2005-2006 and analization the reason and properties of these injures and faults. Many years statistics show that Il0kV transformers with 6.3MWA and higher power that were made in Russia, have been working for 20-40years without any special fixing and heating.Injures and faults that occurred in the electrical system in years 2005-2006, shown in Table 1, Figurel.It shows that there are 522 faults were registered and 29 of them were on-11 0-220kV transfonners. Also there were 16 faults of II0-220kV air line, and 150 (93.7%) of them were on Il0kV line. Abstract-In result from several reasons technical injures and fault of electrical transmission lines have not decreased in Mongolia.For lOOkV and more voltage transmission lines, the number of the shut down in electrical lines, tend to increase year by year. The most of these shut down processes the result of thi wrong operating consequent on the long time usage and decrepitude of relay protection.Safety and stability ofthe electrical system depends on the normal, distinct and good operation of the protection equipment and accuracy ofthe measurement tools.Consequently, we need to modify the relay protection and automation equipment. We have to change these old protection and automation equipments by new technology such as microprocessor terminal tools and digital protection tools.This changing and modifying will be the major factor and step to decrease electrical line fault and shut downs number in electrical transmission system.

Artificial Neuron Network Based Faults Detection and Localization in the High Voltage Transmission Lines with Mho Distance Relay

“…According to the measurement zones the remote protection is of four types namely: Mho, Circular, Polygonal and Elliptical. The curves below represent the respective characteristics at the four relays [24,25].…”

“…It is worth mentioning the advantage offered by using the polygonal and elliptical characteristics especially when it comes to protecting the long or medium high-load electrical lines for which the service impedance can satisfy with the control impedance of the start of distance protection relays. Mho and circular characteristics are generally used to protect short HT lines that are not heavily charged [24,25].…”

“…The phase comparison signals S_1 and S_2 for producing the Mho characteristic are defined as follows [24,25]:…”

“…Now, the angle between S1' and S2' is outside the range specified in equation 1, the relay does not work. The constant ZR∠ θz parameter marks the diameter of the circular characteristic that passes through the origin [24,25].…”