Buck Switching Hydraulic Source Stability And Energy-saving Research

A practical advantage of hydraulic systems is their multiple-actuator characteristic. At present, there are three kinds of multiple-actuators hydraulic systems: throttle control system, load sensing system and secondary regulation system. But there is disadvantage in each system.The switchmode hydraulic power supply, which was put forward recently, can realize the adaptation to the load of every actuator, by adjusting the supplied pressure. Through the control of PWM signal, the switchmode hydraulic power supply can output proper pressure, which is adaptive to the load. As a new theory, there are still some problems of switchmode hydraulic power supply. Switchmode hydraulic power supply can adapt to the load, but in the course of pressure buck and pressure boost, the efficiency still needs to be improved. And there is cavitation in the pressure buck switchmode hydraulic power supply.At first, this article solves the problem of the stability in the pressure buck switchmode hydraulic power supply, through introducing the return pressure into the pressure buck switchmode hydraulic power supply. Secondly, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed, and it researches the relation between the frequency of the switch and the efficiency of the system, through the simulation and the; experiment. Finally, we put forward the control policy of the switch frequency and the return pressure, in order to get the optimal efficiency of the system.In chapter 1, the article summarizes all kinds of hydraulic systems, which can adapt the load, and the shortcoming of these systems. Next, the conceptionof switchmode hydraulic power supply and the limitation of this system are introduced.In chapter 2, aiming at the cavitation in the pressure buck switchmode hydraulic power supply, the relief valve is introduced in order to improve the stability of this system. In this chapter, the principle of the pressure buck switchmode hydraulic power supply with return pressure is also illuminated, and each component's mathematical modeling is built in order to analyze the dynamic characteristic.In chapter 3, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed. And we lay emphasis on analyzing the influence of switch frequency to the efficiency.In chapter 4, on the basis of the constitute of energy loss, the objective of energy loss is established. We minimize the objective, through optimizing the return pressure and switch frequency.In chapter 5, conclusion.