Analysis of Real-time Noise Signal Characteristics of Power Transformer Based on All-phase Fast Fourier Transform

Analysis of the time and frequency domain characteristics of the real-time noise signal of the transformer is beneficial to the research of active noise control technology in substations. When performing spectrum analysis on transformer noise, the All-phase fast Fourier transform (FFT) spectrum analysis method has more advantages than the traditional analysis method. This method is used to process the real-time noise signal of a transformer. As can be seen from its spectrum chart, the transformer noise is based on 100Hz as the fundamental frequency. The noise energy reaches the peak at 100Hz and 200Hz. In addition, the A sound level of the transformer noise signal can be calculated through the Paseval relationship. The A sound level changes smoothly with time and has a small fluctuation amplitude. Although the transformer is a large and complex noise source, the primary sound field generated by it is stable and conducive to implementation of active noise control system.