Design of a multi-poppet on-off valve for wave energy converters

Fluid power systems are the leading technology for the power take off system in ocean wave energy converters. However, fluid power systems often suffer from poor efficiency, especially in part loads. This degrades the PTO system efficiency and therefore lower the energy production. To overcome the issues with poor system efficiency a discrete fluid power system is proposed as a main part of the PTO system. For the discrete system to be feasible large fluid power switching valves are needed. The current paper presents a two stage 1000 L/min@5bar multi-poppet on/off valve with a switching time less than 15 ms. The pilot stage is directly actuated and utilises internal valve pressure as supply and an external tank connection as drain. The current article presents the design process leading to the final valve design. This includes the geometric design of the main stage, the choice of pilot valve, structural mechanical issues and modelling and simulation of various valve configurations. Hence in the design process a wide variety of topics are combined to chose the best valve configuration.