Progress in Research on Active Control of Transformer Noise

摘要

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