Active control of transformer noise by using power line signal as reference

The hum noise generated from the distribution transformers is annoying and is significant when the transformer is installed near the residential area. This hum noise consists of harmonics of 100 Hz, when the power line frequency is 50 Hz. A new type of active noise control method has been proposed in this paper to combat such low-frequency harmonically related noise. The method is based on generation of required harmonics from the power line signal consisting of 50 Hz frequency using two adaptive filters. Through simulation study it has been shown that the proposed technique is able to accurately generate the mix of noise frequency components with the frequency change. The method also tracks the change in power line frequency and generates the corresponding anti-noise to nullify the noise.