Through the strategic integration of hydraulic pumps and their electric motors, significant advancements in pump performance and energy efficiency have been achieved. This trend, which emerged since the 1990s and was previously detailed as specific product examples, continues to evolve with each company's unique approaches. The fundamental configuration of electrically driven hydraulic systems involves fixed induction motors that continuously drive either fixed-capacity or variable-capacity pumps at a constant speed. By utilizing relief valves to discharge excess hydraulic flow from the circuit while maintaining supply pressure, substantial progress has been made in energy conservation:

(1) According to the load situation, the optimal speed of the inverter controlled induction motor and variable capacity pump is adjusted to reduce the remaining flow;

(2) Improve variable speed performance and full efficiency by adopting permanent magnet synchronous motor;

(3) The servo motor and pump are used as the hydraulic source to eliminate the power loss in the control valve, and the 1-pump-1 actuator mode that directly drives the hydraulic cylinder and other actuators is introduced as the energy-saving hydraulic source products.