Computation And Simulation Of Transient Voltage In Lightningproof Transformer Based On Wave Reflection

Transformer belongs to the electrical devices which is vulnerable to lightning altack. Power system would lose its stability once a transformer suffers from the lightning attack, and thus economic lost would be turned out to the subscribers. This paper shows the design of a new type of lightning-proof transformer to enhance the lightning protection performance of the transformer.This paper introduced the mechanics of New Type Lightningproof Transformer (NTLT) and presented the computing formula of the inductance and the capacitance of the transformer. The simulation of the transient process of the NTLT under the lightning waves is given.The first part of this paper is to analyses the frequency spectrum of some lightning waves, and to give a particular analysis of the function of the restraining of the induction overvoltage to the NTLT using reflection wave fundamentals. Also, the protract method of the equivalence circuit of the columnar windings of the transformer is given.The second part introduced the computing formula of the inductance and the capacitance of the transformer and the deduction of these formulas. The distribution parameters of the 3 phases NTLT is computed and is proved by the facts of the measurement.The simulation model based on Simulink state-space block of the language of MATLAB is used to give the image of the transient process of the lightning wave voltage function. Positive and reverse transformation ofovervoltage simulation is included. The attached windings of NTLT have satisfactory effects on restraining the two types of overvoltage. Through the research of the NTLT, it could be concluded that this new type lightningproof transformer is efficient and effective.