Grounding Gird Modeling And Method Of Fault Diagnosis

Ground ing refers to an electrical connection in some node of a power system orconductive parts of electrica l equipme nt between the earth, it can be used as a channe lfor current flow, It can guarantee that the electric potentia l o f electrica l connectionsma intain in a specific allowable range. As an important part of power statio n andsubstation, the grounding grid is the funda menta l guarantee and key steps ofma intaining the safe and reliable operatio n safety of the operating personne l andelectrica l equip ment. Bes ides, its performance has been widely attended by the staffof the do mestic and internationa l power. The conductor o ften buried in theground,thus ground ing conductors and lead wires are easy to corrode，even break updue to poor weld ing、 soil corrosio n and the affection of s hort circ uit current.As the conductor of the grounding gr id is bur ied in the gro und, the factors that poorweld ing, and welding leakage during the construction, soil erosio n and ground short-circuit curre nt electric effect will lead to grounding grid conductor and wire erosio n,even fracture, so that caus ing the performance deterioratio n of ground ing grid e lectrical connection. There fore, this research in the grounding grid fa ult dia gnose has a veryimportant significance.This paper mainly includes the following several aspects:Take EMTP electromagnetic simulation software as a platform, establis h thetransmiss io n line parameters model consists of resistance, inductance, capacita nce.The topology and the parameters of the mode l can be configured according to theactua l, it provides effective support for the simulation data of the ground ing grid fa ultdiagnosis. The simulation results prove the feasibility of the model.Study the influence on the node volta ge waveform variatio n of the excitationsource and branch fa ult location, and put forward the oblique and exc itation source ofthe simulation model can avoid the measurement error caused by slip direction.Use high freque ncy excitatio n and wavelet trans form to extract the fa ult feature,that is, first, the grounding grid app lied with high freque ncy exc itation, accesses thenode vo ltage wave form, and uses db3wavelet to decompose the signals before andafter the fa ilure, Constructs comprehens ive energy characteristics of gro und ing gridfault slip vector. On this basis, a grounding grid fault diagnos is method is give n basedon neural network. Simulation results prove the validity and accuracy of this method.