Electro-hydraulic Unit with Mixed Control

In the context of the recent development of digital hydraulics, direct drive hydraulics (DDH), and pump-controlled hydraulics, this paper proposes a mixed method of converting electrical energy into hydraulic energy, with superior energy efficiency. Flow control is achieved through a combined strategy: Digital Flow Control (DFC), by switching valves with known flow capacities, simultaneously with the speed control of the induction motor via a frequency converter. Numerical simulation results validate the proposed method and highlight advantages in terms of reducing hydraulic shocks and providing flexible flow control.