Study on abnormal power failure shutdown control of magnetic suspension centrifugal compressor

The rotor of a magnetic suspension centrifugal compressor is supported by bearing, and power failure will cause the high-speed to fall directly onto protective bearings, affecting reliability compressor. To solve this problem, paper proposes an abnormal shutdown control method with semi-switching modulation inverter. Firstly, overall scheme designed, its feasibility analysed in detail through mathematical modelling. Secondly, aiming at non-linear, time-varying gain uncertainty characteristics system, voltage strategy based on parametric self-regulating sliding-mode variable structure proposed, stability analysed. Finally, proposed experimentally verified, results show that does not depend electric angle motor compared existing methods, can achieve zero-drop speed shutdown, which greatly improves