The Research Of Substation Invasion Wave Record System

Substation as a key component of the power system plays a quite important role in the power system. Once the substation happening the lightning accident, it will result in large scale power outages, which will cause the severe consequences. Because of its insulation recovery ability is not strong, when the main electrical equipment in the substation suffered lightning damage, these electrical equipment are difficult to recover and it will bring great damage to the power system. We can see that the intrusion wave has an important impact on the substation, the intrusion wave will seriously threaten the safe operation of substation, which will cause extremely serious consequences.The overvoltage of substation invasion wave is an important factor for affecting the stable operation of power system. Also, the overvoltage level of intrusion wave is the measure of estimating substation insulation coordination level.Above all, it is very important to carry out the study of the lightning invasion wave happened in substation.In the substation we install the equipment system recording the occurrence of each invasion wave, which plays an important role in the accident records, analyzing the cause of the accident,evaluating the level of insulation coordination of electrical equipment in the substation, finally ensuring the safe operation of the power grid is of great significance.Firstly, this paper introduces the research methods of the substation invasion wave, including the simulation of the transformer substation line, and the models of lightning current, transmission lines, tower and line insulator string. Then this paper analyzes the basic principle of the monitoring and recording about transformer substation lightning invasion wave, and puts forward the parameter calculation method of resistance, inductance, and capacitance in the capacitive voltage transformer (CVT) loop under the high frequency. And analyzing the equivalent parameter calculation error's influence on the overvoltage monitoring through the simulation model. Finally this paper proposes a wave online monitoring method based on the current CVT, and has a detailed description about the calculation steps and the equivalent model. Based on the on-line monitoring method, this paper develops a bus overvoltage monitoring system by using substation bus CVT loop current. The system consists of two parts, named the current monitoring terminal and invasion wave overvoltage monitoring terminal. This system can realize the real-time online monitoring about the transmission line traveling wave current and invasion wave overvoltage of the substation, to realize accident monitoring statistics automatic, intelligent and informational.Finally,the comparison of online monitoring data about substation invasion wave and the measured wave shows that the on-line monitoring system can be sustained and effective operated.