Adaptive surge detection of magnetic suspension centrifugal blower based on rotor radial displacement signal and SOGI-FLL with prefilter

Abstract

For the surge detection problem of high-speed magnetic suspension centrifugal blower, a second order generalized integral-frequency locked loop with prefilter (SOGI-FLL-WPF) is used for surge detection. This method is utilized to normalize the amplitude and frequency of the surge signal by using the rotor radial displacement signal in the magnetic suspension blower. So that the response speed of detecting surge signal is not affected by the frequency and amplitude, and the frequency of the blower surge vibration signal is tracked adaptively. As a result, the fast response ability of the surge signal detection is improved. Specifically, firstly, the rotor radial displacement signal is collected in real time. And then, the rotor speed is identified by SOGI-FLL, and the identified speed information is input to SOGI for notch. Finally, the surge detection is carried out by SOGI-FLL-WPF for the signal after notch. The 105 kW magnetic suspension centrifugal blower is applied for the surge detection experiment. The experimental results show that the surge detection method based on rotor radial displacement signal and SOGI-FLL-WPF can detect the surge signal immediately after its occurrence. The proposed detection method needs no additional detection unit, and has the advantages of simple algorithm, fast response speed and small amount of calculation. In addition, it can effectively reflect the change of frequency in the process of surge.