Thermal Error Modelling and Compensation of The Voice Coil Motor Force for Hydraulic Valves

Abstract

The heat generation and transfer of a voice coil motor (VCM) used for the electrohydraulic proportional pressure valve are investigated. A thermal-network model is set up to predict the VCM component temperature variations. The thermal error and compensation of the output thrust force have been studied. The temperature and the force are measured. The step responses of the valves driven by the VCM and the proportionalsolenoid are presented. The results indicate that the heat transfer model of the VCM is feasible. The coil temperature rises faster than that of the other parts of the VCM. The inner surface temperature of the wall is mainly determined by the copper coil temperature due to the heat convection. The temperature distribution of the wall outer surface is uniform. The proportional pressure control valve driven by the VCM shows a faster step response than the one driven by a proportional solenoid. The fall time of the VCM driving valve is significantly shortened by about 85%. The frequency response of the proportional pressure control valve driven by the VCM is also better than the one driven by the proportional solenoid. The phase lag is reduced by about 80 % with a 5 Hz input signal.