Thermal Analysis of Solenoid Actuators

From an adequate model of a system it might be possible to estimate its certain physical quantities that could not be measured directly or at a great expense. Usually, mechanical parameters, such as position and velocity are estimated by measuring only electrical signals. This concept is referred as "sensorless" and has the major benefit of saving costly external sensing elements, thus reducing costs and improving robustness. Regarding solenoid actuators, the position and velocity of the moving part is usually to be estimated. A literature survey has showed that in corresponding solenoid models thermal behavior is not properly considered. In case the device is subject to significant temperature deviations or internal heat gradients, model parameters, thus estimation accuracy may suffer from significant "thermal" uncertainty. In this paper, major thermal phenomena related to valve actuators are highlighted. The concept of multilayer laminates is proposed for modeling and an analytical solution sought. General treatment of the underlying problem is also presented with the most important modeling principles discussed.