Study on improvement of energy regeneration of switching inertance hydraulic system by using antiresonance

Abstract

The energy efficiency of the conventional flow control of hydraulic systems using the pressure loss of throttle valves, which are widely used in construction machinery, is very low. If the switching inertance hydraulic system which is a kind of PWM control hydraulic system is used, a significant improvement in energy regeneration efficiency can be expected. However, it is known that as the switching frequency of the valve increases, the regeneration rate decreases as the vibration mode due to the elasticity of the oil in the pipe system resonates with the valve switching frequency or its high-order component. Therefore, the aim of this study is to reduce the vibration due to the elasticity of oil in the pipe system and to improve the regeneration rate by using the phenomenon that the response decreases with antiresonance. In order to obtain a high regeneration rate even if the duty ratio of the valve is changed, the shape of the pipeline is studied so that the fundamental frequency component of the valve switching frequency and the frequency components of all harmonics up to the third order could be anti-resonant frequencies at the same time. Some calculations are carried out using the response analysis method and definition of efficiency, and it is shown that a higher regeneration rate can be obtained in the case of the proposed pipe shape than in the case of a straight pipe.

Keywords

• hydraulic system
• pwm control
• energy regeneration
• antiresonance
• fluid elasiticity