Online current signal de-noising of magnetic bearing switching power amplifier based on lifting wavelet transform

作者：Zhang, Huijuan^*; Fang, Jiancheng; Liu, Hu

来源：IET Electric Power Applications, 2016, 10(8): 799-806.

DOI：10.1049/iet-epa.2015.0457

• magnetic bearings
• signal denoising
• wavelet transforms
• power amplifiers
• power filters
• vibration force
• rotor displacement jitter
• magnetically suspended flywheel
• improved threshold function
• sliding data window
• power filter circuit
• current ripple reduction
• spectrum character
• power switch component
• shutoff operation
• conduction
• active magnetic bearing
• lifting wavelet transform
• switching power amplifier
• online current signal denoising

Switching power amplifier is an essential component for magnetic bearing system. However, the current ripple resulted from the conduction and shutoff operation of power switch component inevitably affects the performance of active magnetic bearing. To reduce the current ripple of switching power amplifier, the characteristics of current ripple are first analysed. In response to the spectrum character of current ripple, an online lifting wavelet transform de-noising algorithm, unlike the conventional power filter circuit, is proposed in this study. Moreover, the sliding data window and an improved threshold function are introduced to realise the feasibility of online processing and to improve the de-noising performance, respectively. Finally, plentiful comparative experiments, taking the magnetically suspended flywheel as subject, are implemented. The results illustrate that the proposed algorithm could dramatically reduce the current ripple and that the rotor displacement jitter and the vibration force are suppressed accordingly.

• 出版日期2016-9
• 单位北京航空航天大学