Avoidance of transmission line pressure oscillations in discrete hydraulic systems – by shaping of valve opening characteristics

The architecture of multi pressure line discrete fluid power force systems imposes rapid pressure shifts in the actuator volumes. These fast shifts between pressure levels often introduce pressure oscillations in the actuator chamber and connecting pipes. The topic of this paper is to perform pressure shifts by changing the connection between various fixed pressure lines without introducing significant pressure oscillation.
As a case study a discrete force system is utilised is a Power Take Off(PTO) system of a wave energy converter. Four pressure shifting algorithms are proposed and experimentally tested on a full scale PTO test bench. Two of the algorithms show promising results in two out of the four test cases.