Research On Eddy Current Sensor Applied To Flywheel Battery For Vehicle

Eddy current sensor is a device for non-contact measurement.It has many advantages upon other sensors.Eddy current sensor is studied in the thesis in order to satisfy the engineering requirements for active magnetic bearing system which is applied to flywheel battery for vehicle.Working principle of eddy current sensor is introduced.The parameterized finite element model of the sensor probe is constructed by ANSYS software.The influence of the sensor probe parameters on the sensor output is investigated through theoretical analysis and digital simulation,and the optimal design parameters of the sensor probe are obtained based on the investigation.The method is proposed and carried out to use the multilayer spiral wire of Printed Circuit Board(PCB)as the probe coil.The solutions are developed to deal with the electromagnetic interference,the temperature drift and the time varying drifts of the sensor.The structure scheme and the corresponding circuit to detect the axial drift of the rotor by using the radial sensor are designed.The test results of the static and dynamic characteristics of the sensor show that,the linear measuring range is 0.8mm,the sensitivity is 7v/mm,and the bandwidth is 1.6KHz.The sensor probe has the advantage of convenient manufacture and better consistency.The experimental results show that,the electromagnetic interference,the temperature drift and the time varying drifts of the sensor can be reduced effectively,and the stability of the sensor output is greatly improved.The axial drift of the rotor can be detected by using the radial sensor.The running results of the flywheel battery for vehicle show that,the eddy current sensor developed by the thesis can satisfy the engineering requirements of the Active magnetic Bearing(AMB).