Study On Noise Radiation Of Power Transformer

Power transformer, one of the major equipment for power substation and convertor station, is used to raise or lower voltage and for conversion work between AC and DC. With the development of national economy, more and more substations were rebuilt or extended near the residential area. As power transformer works, it will make higher harmonic noise. Consequently, residents daily routines will be badly influenced. Therefore, it will be great significance in research on the radiation feature of the noise arise from the power transformer, control of the noise caused by substation and creation of the power transformer with little vibration and low noise.This article discusses the generation mechanism of the vibration and noise caused by power transformer, analyzes the transmission way of the iron core and winding vibration, and studies on the reasons of the harmonic wave in accordance with the power transformer operating principle. As a result, essential basis is provided for analysis of noise radiation.The experiment data, firstly, indicate the analysis of the two transformers noise signal in transformer substation, and show the noise SPL and frequency spectrum feature under its normal operation state. Furthermore, the data manifest the analysis of power transformer cooling fan noise, the gain of its SPL and its influence on the test of the power transformer noise. Secondly, the data analyze, under different exciting voltages, power transformer noise signal tested from transformer factory and operated with and without loads and also present a rule that the noise SPL changes with exciting voltages. Besides, the data analyze frequency spectrum feature of the power transformer noiseFinally, the data comparatively analyze power transformer noise frequency spectrum feature tested separately from transformer substation and transformer factory and study the more reasonable loading method for test of power transformer noise.