Since the energy sources of the world dwindle each day and energy costs rise accordingly; efficient usage of power has become a much more important matter. In parallel with this, power efficiency has been a growing concern for hydraulic systems in the recent years, and there are new systems developed to match this purpose. In a standard driven hydraulic system, the hydraulic pump (fixed or variable displacement), is driven by an asynchronous motor that is rotating at a fixed rate and is connected to the mains frequency. It is provided by the valves on the control and power transfer hydraulic system, or occasionally, control valves on the variable displacement pumps. Asynchronous motor converts the electrical energy to mechanical energy (for hydraulic pump). The electric motor is not expected to provide any other functionality. In a variable speed pump driven system, the hydraulic pump is driven by a servo motor. The hydraulic only provides the power transfer. Rotational drive speed of the pomp is controlled by the amount of fluid sent to the system proportionally. Electrical part of the drive has two functions: • Providing energy • Controlling the flow and pressure of the system by altering the rotational speed of the motor-pump unit. Thus, it provides control and adjustment functions of the electric axis. Drive part of this system is comprised of the servo motor and the servo driver required for driving this motor. In the pump part, units with fixed or variable displacement that can be operated in two or four sections depending on the open or closed circuit hydraulic system that will be used. Servo motor drives the fixed displacement (variable displacement) pump. Output flow rate of the system is achieve via multiplying the displacement of the driven pump with the pump rotation of the servo motor. System pressure is measured by the pressure sensor attached to the pump pressure line. Controls are done by the software within the controls. Has high operation dynamics. It is possible to control force, speed and position very accurately.