Analysis And Research Of Lightning Invasion Wave In Substation

The important factor which infects stable operation of electric power system is theinvasion wave over-voltage, while the invasion wave overvoltage level determines whetherthe insulation coordination level is reasonable. In some substation, when equipments wereof unreasonable insulation coordination or their insulation resistance level was inadequatecaused by deterioration, equipment fault should be generated. According to some accidentsin view of Guiyang substation and Fuquan substation, the simulation and measurementanalysis is developed, which can be used to seek the reason.Firstly, according to the main electrical wiring and the equivalent parameters ofvarious electrical equipments under the impulse voltage, the calculation isograms with ATPsimulation modeling is proposed, in Guiyang substation and Fuquan substation. Secondly,according to the probability of lightning distribution characteristics, the wave impedance oflightning channel and the law of lightning wind and back striking, the lightning motivationsource is simulated. Under comparatively rigid conditions, it can be checked out whetherthe impulse overvoltage, which all the equipments was bear at the moment of lightningwind and back striking, is over the normal margin.A substation system which is applied to monitoring invasion wave overvoltage wasdeveloped, based on simulation analysis. It consists of two parts—Invasion wave currentMonitoring Terminal and Invasion wave Over-voltage Monitoring Terminal. EachMonitoring Terminal is composed by sensor module、data acquisition module、wirelesscommunication module and source module. This system is able to realize real-time on-linemonitoring transmission line traveling wave current and substation bus invasion waveovervoltage. Comparing the on-line data computed by this system with the date ofsimulation analysis, the further demonstration was obtained.The achievements of this paper avoid the traditional drawbacks that substationinvasion wave can only be analyzed by numeric simulation. On the basis of aboveachievements, the over-voltage monitoring system of the substation invasion wave is putforward to realize the online monitoring for lightning over-voltage, thus a newmethodology for over-voltage monitoring in high-voltage grid is proposed.