Research On The Forward And Inverse Problem Of Electric Field Of High Voltage Transmission Line Based On Charge Simulation Method

With the continuous expansion of the power grid and the continuous development of high-voltage transmission technology,the electromagnetic environment of transmission lines has attracted more and more attention.Compared with field measurement,the numerical calculation method has the advantages of time and labor saving,can calculate the electric field at any point,and can well evaluate the electromagnetic environment around the transmission line,so it has developed rapidly.The forward problem of the electric field of the transmission line is the problem of finding the electric field distribution around the transmission line from the transmission line voltage(source seeking field),while the reverse problem is the opposite.In actual engineering,due to load changes and other reasons,the voltage amplitude and phase of the running transmission line will deviate from the standard value.It is not appropriate to use the forward problem calculation to obtain the electric field distribution.At this time,according to the principle of the reverse problem,the actual voltage amplitude and phase can be reversely calculated from the electric field values of some measurement points which under the power line,and then the forward problem can be used to calculate the electric field distribution around power lines.In this paper,the charge simulation method is used as a numerical method to study the forward and reverse problems of transmission lines’ electric field.First,the basic principles,calculation formulas and application steps of the electric field numerical calculation method charge simulation method used in this paper are introduced.Then,the transmission line is simplified,and a two-dimensional calculation model of the transmission line is established.A typical example of a transmission line is calculated,the electric field distribution around the transmission line is drawn,and the law of electric field distribution under the transmission line is obtained.Secondly,a particle swarm optimization charge simulation method is introduced to optimize the position of simulation charges in the wire.The optimization object of the algorithm is only the distribution radius of the simulation charges in the equivalent wire,and the algorithm adaptation value is the potential error of the checkpoint on the surface of the wire.The optimized calculation results show that the potential error of the checkpoint of this method is reduced by at least two orders of magnitude compared with the general method,and the electric field accuracy calculated by the optimized simulation charges group is also doubled compared with the general method.Finally,the feasibility of retrieving power line voltage from the power frequency electric field intensity component of the measuring point is studied.The voltage inversion results and the electric field distribution calculated from the inverse solution show that the voltage inversion algorithm based on the measuring point location optimization has good accuracy and stability.Comparing the component method and the combined value method,it is found that the component method has obvious advantages over the combined value method in terms of formula calculation amount,measurement point height,and near ground inversion calculation accuracy.The calculation results of the component method under the data deviation are tested and analyzed.The results show that the component method is robust.