Research On Fault Location For Transmission Line Based On Distributed Monitoring

With the continuous development of the power industry at this stage,the multi-circuit transmission line on the same tower has become the main method of high-voltage long-distance transmission due to its advantages of increasing the transmission capacity of the transmission line and improving the utilization rate of the corridor.The multi-circuit power transmission method on the same tower also has a higher risk of lightning strike failure,which requires more targeted lightning protection measures and reliable monitoring.This paper analyzes the key application technical issues of the lightning current sensor of the multi-circuit transmission line on the same tower,and improves the accuracy of the lightning current measurement of the line in a targeted manner.This paper studies and analyzes the key application technical issues of lightning current sensors on multi-circuit transmission lines on the same tower,and aims to improve the accuracy of lightning current measurement on the line.For the problem of layer-to-line shielding for multi-circuit transmission lines on the same tower,this paper proposes an improved electrical geometric model for shielding.In the traditional calculation model,the influence of wind speed and monitoring points is added to obtain a more realistic maximum Shielding current amplitude,and compare and obtain the distribution of circumvention fault risk of the line.In this paper,the ATP-EMTP electromagnetic simulation software is used to model and analyze the multi-circuit transmission line on the same tower,the parameter settings of each module and system are improved,the criterion of the insulator flashover is proposed,and the calculation results are compared to o btain the line counterattack fault situation And its influencing factors.In view of the problem that the traditional differential optical current sensing unit is susceptible to external magnetic field interference,this paper proposes a line magnetic protection method based on the optimal installation position,and compares the magnetic field interference under different lightning faults on each line to verify the accuracy of the magnetic protection method.In addition,this paper also proposes the proportion of the magnetic field of the sub-conductor to be measured corresponding to different installation angles,and then derives the complete calculation process of the phase current to be measured.Aiming at the analysis of lightning fault risk distribution and optimal installation location of lightning current sensors,this paper presents the structural design of the sensor’s operation on the transmission line,and analyzes the application errors that may exist when the lightning current sensor is actually applied The error margin of each influencing factor is proposed to ensure that the lightning current sensor can meet the measurement requirements as much as possible.