Transformer Protection Principle Based On Wavelet Transform To Explore And Achieve,

In recent years, the wavelet transform analysis method has been developed rapidly. As the wavelet transform possesses the properties of multi-scale analysis and time-frequency domain localization, it is particularly well adapted to process sharply changing signals, and to extract characteristics of these signals. In order to meet needs of reliability and speediness of power transformer protection, and to have protection blocking reliably in the presence of magnetizing inrush current, the wavelet transform is applied to the discrimination between inrush current and fault current. The article studies several new methods to distinguishing between internal faults and inrush currents based on wavelet analysis, and gives two approach which can be adapted to practical application. In the end an advanced protection scheme is brought forward, which is based on 32-bit MCU. DSP chip and real-time operation system.