The Axial Magnetic Levitation Bearings Displacement Detection And Control System

Magnetic bearing involving machinery, electronics, measurement, control, and many other subjects, is a typical mechatronic product. The technology is difficult and the cost is very high. At present, most of the research is at the laboratory stage in our country. According to the application needs this paper conducted a study on axial magnetic bearing, at the same time it must meet the performance requirements and economic indicators.The main content of this paper include:Firstly, made a research on Eddy current displacement sensor and focused on analyzing the methods of improving its original sensitivity. Designed the circuit design and made the PCB board. The final design's raw sensitivity of Eddy current displacement sensor is 1.5mV/μm, which meet the requirements of magnetic bearing displacement detection.Secondly, took advantage of constant voltage source and pulse-width modulation method as power amplifier. Mainly analyzed the switch frequency to influence on the performance of the magnetic bearing, and got the best switch frequency value with an experimental method. Finally designed all parts of the power circuit, and successfully applied to the axial magnetic bearing system.Thirdly, built and simulated the mathematic model of the axial magnetic bearing system. Mainly analyzed the parameters of PID controller to influence on the control system. Finally realized the PID controller by analog circuits and applied it in the control system.Overall debugged and tested the performance according to the axial magnetic bearing our own structured. The floating position is within the range of±2μm. The bearing stiffness is 81.3N/μm, while the disturbing force can afford 120N. Axial magnetic bearing designs further validates the success of the technical feasibility, but also for future multi-degree magnetic bearing research references.