Pressure Controlling Performance of Constant Displacement Electro-hydraulic Power Source Based on Direct Torque Control

doi:10.3901/JME.2022.20.453

Abstract

Abstract: The energy efficiency of the electro-hydraulic power source can be improved by coordinating its speed and displacement, which is also the research hotspot at present. With the development of frequency conversion and servo technology, speed variable electro-hydraulic power source is more and more applied in industrial production and aerospace equipment. At present, the flow control of power source can adopt variable displacement control or variable speed control. These two control methods are very mature and widely used. However, in the pressure control, a constant pressure pump combined with pressure feedback is often used to realize the pressure control. If the pressure is controlled via the pump speed, it is difficult to adapt to the random and rapid changing of load flow rates. A high-efficiency servo motor is used to drive the quantitative pump directly, and a pressure control scheme based on torque control is proposed. When the load pressure changes, there is no need to control the motor speed, which has the advantages of faster dynamic response and simple system structure compared with the conventional constant pressure displacement variable pump. Through theoretical analysis and experimental research, the results show that the design scheme can achieve the pressure control. Under the same test conditions, compared with the conventional constant pressure pump, the pressure response time is reduced from 160 ms to 50 ms.

Key words: electro-hydraulic power source, pressure control, speed variable, torque control

CLC Number:

TH137

GE Lei, YANG Fei, QUAN Long, ZHANG Hongjuan, YAN Zheng. Pressure Controlling Performance of Constant Displacement Electro-hydraulic Power Source Based on Direct Torque Control[J]. Journal of Mechanical Engineering, 2022, 58(20): 453-460.

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