Method of active control of transformer noise and its example

摘要

Electric transformer noise has been a great concern due to its low frequency noise that often disturbs people especially during night. However, low frequency characteristics of the noise; in fact, it radiates 120, 240, and 360 Hz noise in our case study, doesn't allow applying conventional noise control strategies. It has an enclosure that is designed for the required safety, and recently to reduce the noise for the transformers that have to be located nearby residential or office area. ANC method for reducing nose from relatively large transformer is suggested. The method attempts to decrease the radiated noise outside the enclosure by reducing the global acoustic potential energy actively in the. The method depends very strongly on the location of error sensors and actuators. We demonstrate the way to determine their locations experimentally. Experimental results shows that externally radiated noise was decreased about 10 dB at 120Hz and about 2.2 dB at 240 Hz.