An electro-hydraulic control system with energy recycling

When traditional electro-hydraulic proportional valve or servo valve controlled systems are used to drive unbalanced external load, the hydraulic valve itself exists throttling losses. At the same time, the excess kinetic or potential energy of external load is consumed in the form of heat. In order to reduce energy loss and recycle external load energy, this paper puts forward a kind of electro-hydraulic control equipment which can recycle energy. It consists of directional valve, hydraulic motor, generator, power transformation device. In details, the directional valve is used to control the fluid direction of hydraulic actuator, hydraulic motor is connected to the fluid return channel of the directional valve. A generator is connected to hydraulic motor so that the back pressure of the actuator can be controlled by adjusting the torque applied on the hydraulic motor. In this way, the trajectory of the actuator is controlled. The mechanical energy applied on the hydraulic motor can be converted to electricity via the power conversion device, and then transmitted back to the grid. The simulation and experiment results prove that the proposed scheme is feasible.