Study Of Transformer Protection Based On Wave Character Of Voltage-Current

Various states of power transformer are simulated with Electromagnetic Transients Analysis Program(EMTP). Using the ratio of voltage and current differential judges whether the transformer has magnetizing inrush from the transformer's electromagnetism character. Through transforming the current wave by wavelet, using energy differential of the result of the wavelet transform judges whether the transformer occurs interior fault. Combining the advantage of two parts, a new theory of transformer protection basing on wave character of the voltage-current is come out. The simulation results prove the protection theory reliable, rapid and simple after numerous simulations. It can also determines the turn-to-turn short current of transformer quickly and efficaciously.