Study on High Dynamic Variable Speed Hydraulic Control System

A new type of high dynamic variable speed hydraulic control system is developed in this paper. In this system, a fixed displacement hydraulic pump is driven by an electrical motor which is controlled by a frequency inverter, so the discharge of the pump can be modified by changing the speed of the motor. A proportional directional valve is used to acquire higher low-speed control precision and faster dynamic response while the system is decelerating. In order to improve the dynamic response while the system is accelerating, an energy regulation device is employed in the system. The digital simulation results show that this system has higher efficiency than valve control system. Further more it has faster dynamic response and higher low-speed control precision than normal variable speed hydraulic control system.