Modeling and Validation of High-Temperature Electromagnetic Actuator

Electromagnetic actuators are able to meet demanding requirements, such as operations in very high temperatures. For such applications, it is necessary to know how the load capacity of the actuator is influenced by the operating temperature. This paper presents a nonlinear magnetic circuit model of an electromagnetic actuator and its experimental validation when the actuator is operating in a high-temperature environment up to 500 °C. In order to predict the actuator force, the magnetic properties of the core material (SUS410) at several temperatures up to 500 °C are measured. A modified Fröhlich-Kennelly equation for representing the magnetization curve is proposed. The parameters of the equations are identified through curve-fitting. The temperature-dependent magnetization data are utilized for the magnetic circuit modeling and the finite-element analyses (FEAs). A test rig is set up to measure the output force of the actuator placed in an oven while varying the temperature up to 500 °C. The predictions by the magnetic circuit model are within 5% from the results by the FEAs and the measurements, which proves the validity of the model.