Theoretical Studies of a Switched Inertance Hydraulic System in a Four-Port Valve Configuration

A switched inertance hydraulic system (SIHS) can provide an efficient step-up or step-down of pressure or flow rate by using a digital control technique. In this article, analytical models of a SIHS in a four-port high-speed switching valve configuration are proposed, and system characteristics and performance are studied. Using these models, the flow responses, system characteristics and efficiency can be estimated and investigated effectively and in detail. Numerical simulation models are used in validation of the analytical models. Results show that the models are accurate and reliable, and give a very promising way to understand the characteristics and trend of a four-port switched hydraulic system. A discussion and comparison is included of the three-port valve and four-port valve configurations, in terms of system power loss. It is found that the four-port configuration has higher losses, but provides greater control flexibility.