The Potential of Energy Recuperation in Valve Controlled Mobile Hydraulic Systems

In this study the individual metering valve technology is put forward as a suitable base for a complementary energy recuperation system (ERS). The meter-out port of such a valve arrangement interconnects to the ERS that consists of a rotary hydraulic machine controlling the port pressure. The emphasis is on reducing the losses in overrunning load conditions and parallel actuation of multiple loads. In such load cases, the pressure drop across the valve is relocated to the hydraulic machine within the ERS. The ERS is controlled with the objective of reducing the throttling losses without sacrificing the advantageous dynamic characteristics of a valve controlled system. This article addresses relevant control strategies and presents methods to evaluate different types of ERS with regard to energy efficiency.