Theoretical and experimental studies of a switched inertance hydraulic system including switching transition dynamics, non-linearity and leakage

This paper reports on theoretical and experimental investigations of a switched inertance device, which is designed to control the flow and pressure of a hydraulic supply. The device basically consists of a switching element, an inductance and a capacitance. It is able to boost the pressure or flow with a corresponding drop in flow or pressure respectively, analogous to a hydraulic transformer. In this paper, an enhanced analytical distributed parameter model in the frequency domain, which includes the effect of switching transition, non-linearity and leakage of the valve, is proposed and validated by simulation and experiments. A flow booster test rig is studied as a typical system. Simulated and experimental results show good performance, and accurate estimation of system pressure and dynamic flowrate can be obtained by using the enhanced analytical model. The model is very effective for understanding, analysing and optimising the characteristics and performance of a switched inertance device. It also can be used to aid in the design of a switched inertance hydraulic system.