Application of wavelet transformation on on-line measurement of leakage current of zinc-oxide lightning arresters

In order to improve the measurement accuracy of leakage current of zinc-oxide lightning arresters and to ensure the validity and reliability of fault diagnosis for the equipment, wavelet transform is applied to eliminate the noise in the test signal. Then, correlation analysis is applied to compute the resistive fundamental harmonic leakage current. Simulation results show that, comparing with the traditional signal processing method, wavelet transform can pick up the leakage current from noise satisfactorily, and furthermore, it can reproduce the vicious character in leakage current signal accurately, which is important for early fault diagnosis of equipment. By applying correlation analysis, its measurement accuracy is highly improved, which ensures the reliability of the fault diagnosis for equipments.