Study On Switching Power Amplifier Of Magnetic Bearing For High Speed Magnetic Suspension Motor

Compared with traditional mechanical bearings,magnetic bearings have many advantages such as no friction,low loss and so on.With the improvement of technology and the increase of sales,the working performance and stability of magnetic bearing are very important.In this paper,switching power amplifier,the core part of magnetic bearing system is studied,and the optimization control and stability of multi-leg switching power amplifier are analyzed and improved.Firstly,this paper describes the application of magnetic levitation technology and the advantages of high-speed motor using magnetic bearing technology.By analyzing the development trend and research of magnetic bearing technology,it is pointed out that the performance of switched power amplifier in magnetic bearing system is very important.Therefore,this paper analyzes the performance indicators of switched power amplifier for magnetic bearing and the influence of different performance indicators on the stability of magnetic bearing system.This part indicates the research direction of magnetic bearing power amplifier and the current problems to be solved,including current tracking performance and reliability.Then,this paper analyzes the structure and principle of magnetic bearing switched power amplifier,and explains the advantages and disadvantages of multi-bridge arm topology compared with traditional structure power amplifier.In order to improve the performance of multi-bridge arms as much as possible,an improved algorithm based on single-period algorithm is proposed in this paper to optimize the control of common bridge arms through model predictive control and realize the optimal control of five groups of currents.In order to solve the current loss caused by winding resistance,an accurate mathematical model is established to optimize the duty cycle calculation of the load bridge arm to achieve accurate current compensation.Then,this paper introduces the failure problems of switching power amplifier and presents a topology with open circuit fault tolerance function.The principle of fault-tolerant operation and fault detection method are introduced,and the validity of the topology is demonstrated by simulation.Experiments are also carried out to verify the validity of the proposed method and topology.Finally,this paper summarizes the research and puts forward some prospects.