基于液压变压器的动力输出系统压力-转速协同控制研究OA

To suppress the main-circuit pressure pulsation and speed fluctuation of the variable-displacement motor of a wave energy hydraulic power take-off system,and to reduce the throttling loss caused by traditional valve control,a pressure-speed coordinated control method based on a hydraulic transformer is proposed.The proposed method uses a hydraulic transformer composed of a variable-displacement pump and a fixed-displacement motor as the pressure-flow conversion stage to replace the throttling pressure regulation stage of the traditional proportional flow valve.By regulating the displacement of the variable-displacement pump,the output flow of the hydraulic transformer is matched with the load demand,while the displacement regulation of the variable-displacement motor is used to improve the inlet pressure response,so that the hydraulic power take-off system can maintain relatively stable main-circuit pressure and output speed when wave height and period vary.Based on co-simulation with Simulink and AMESim,models of a valve-controlled throttling speed-regulation hydraulic power take-off system and a hydraulic power take-off system using the proposed constant-pressure and constant-speed control method based on a hydraulic transformer are established,and comparative simulations are carried out under varying wave conditions such as wave height reduction and period shortening.The results show that,compared with the traditional valve-controlled throttling speed-regulation system,the hydraulic power take-off system using the proposed constant-pressure and constant-speed control method based on a hydraulic transformer improves speed stability,reduces main-circuit pressure fluctuation,and exhibits faster response characteristics under sudden wave condition changes,providing a new approach for energy-saving optimization of wave energy hydraulic power take-off systems.