Study On Control System Of Maglev Axial Blood Pump

Maglev Axial flow blood pump has many advantages, such as small size, light weight and it can effectively solve the problem of thrombosis and hemolysis, etc. So it has been the hotspot and focus of the world-wide research on cardiac assist device. This paper aims to develop a magnetic bearing control system of the maglev axial flow bood pump.Active magnetic bearing system (AMB) mainly includes the following components: sensors, controller, power amplifier, electromagnets, and rotor .The first three parts constitute AMB control system. This thesis focuses on the control system of the AMB .The main works are as follows:Firstly, the structure of the AMB and designed parameters are gived. Author derived a mathematical model of the magnetic bearing system to lay the foundation for the controller design.Secondly, the paper designes two types of sensors which are applicable to the maglev axial flow blood pump. They are sensorless systems and the sensor system based on hall elements. Author gived their detection principle, mathematical model, the hardware circuit and test results respectively.Thirdly, the paper introduces the selection and comparison of the controller. Author designed the hardware circuit of the controller, gived the control parameter calculation algorithm and obtained better control parameters.Fourthly, the paper designes two types of amplifiers: PWM switching power amplifier and linear amplifier. Author introduced the two types of the amplifier design process and gived the performance of their test results.Fifthly, sensor, controller and power amplifier, electromagnet and rotor constitute a closed-loop system. Author carried out its suspension experiment and temperature experiment of the AMB. The experiments results show that the designed control system can better meet the requirements of axial AMB of the maglev axial flow blood pump. The control effect is good.