Pressure regulator valve by Bondgraph

The Bondgraph represents mechanical, hydraulic and electric components with their power flow in an unified manner and is used here for a three port regulator valve for pressure. It consists of a valve spool and a valve body or casing, and an electric solenoid. The valve assembly has three ports and two variable metering orifices, represented by modulated R-elements. They are the combination of a proportional and a quadratic characteristic, each by separate R-elements. One of them is in conductance causality, the other one in resistance causality and they are on a 1-junction. This gives an algebraic loop that can be broken by a first order element. Even with a closed port, there is some passage, or leakage in the valve due to clearance. The solenoid is non-linear. The whole is represented by a Bondgraph and simulated by the TUTSIM program, where real parameters are used. This leads the valve dynamics much quicker than solving differential equations