Progress in Research on Active Control of Transformer Noise

摘要

Investigations on active control of transformer noise started more than 50 years ago andrnthere has been a lot of research on the area since then; however, successful commercialrnapplications are still quite rare. This paper first reviews the history of the research onrnactive control of transformer noise, and then reports recent progresses on this area atrnNanjing University. One progress is that a method of using an internally synthesized signalrnof preset frequencies as the reference signal, where the feasibility of applying the method inrnthe filtered-x least mean square algorithm and a specific transformer algorithm isrninvestigated, and the effects of frequency mismatch and secondary path delay on the steadyrnstate behavior of the two algorithms are analyzed and compared. The other progress is onrnthe usage of flexible and economic decentralized multi-channel analog feedback controlrnsystems in active control of transformer noise, where the noise reduction performance ofrnthe multi-channel system can be predicted with the independent single channel controllerrndesign and geometrical configuration of the system. Finally, future directions for researchrnon active control of transformer noise systems are discussed.