The Modeling and Simulation of a Proportional Solenoid Valve

Abstract

A nonlinear dynamic model of a high speed direct acting solenoid valve is presented. The valve consists of two subsystems; a proportional solenoid and a spool assembly. These two subsystems are modeled separately. The solenoid is modeled as a nonlinear resistor/inductor combination, with inductance parameters that change with displacement and current. Empirical curve fitting techniques are used to model the magnetic characteristics of the solenoid, enabling both current and magnetic flux to be simulated. The spool assembly is modeled as a spring/mass/damper system. The inertia and damping effects of the armature are incorporated in the spool model. The solenoid model is used to estimate the spool force in order to obtain a suitable damping coefficient value. The model accurately predicts both the dynamic and steady-state response of the valve to voltage inputs. Simulated voltage, current, and displacement results are presented, which agree well with experimental results.