Design, modeling, and pressure control of a 300-kW-class hydraulic pump/motor loading system with energy regeneration

Abstract

Energy consumption and temperature rise are challenging in traditional high-power hydraulic pump/motor loading systems. This study develops a novel loading system configuration where energy can be regenerated by mechanical compensation. A compound loading method is proposed to implement static loading with displacement control and dynamic loading with valve control, respectively. This method combines the high energy-regeneration capability of the displacement control and the fast dynamic response of the valve control. Pressure controllers are designed based on system modeling and characteristics analysis. For static loading, a proportional–integral–derivative controller is employed, and the variation of rotational speed is taken into consideration to reduce overshoot and oscillation. For dynamic loading, an off-line learning method is developed by using least square calibration to keep the relief flow rate at a low level without flow meters. An experimental setup of a 300-kW-class loading system is manufactured, and experiments in various loading modes are performed. The results show that the designed system and controllers have accurate pressure tracking performance and low energy consumption.