Characteristic analysis of valve-pump parallel connection in a variable frequency hydraulic system
by Haigang Ding; Jiyun Zhao
International Journal of Modelling, Identification and Control (IJMIC), Vol. 21, No. 3, 2014

Abstract: To solve the problems existing in variable frequency hydraulic system (VFHS), such as bad low speed stability, low response and bad speed smooth at start-up and stop, a valve-pump parallel connection variable frequency hydraulic system (V-PVFHS) is proposed, in which a flow valve is parallel to a variable speed pump to form a bypass leakage path. Mathematical model and simulation model are constructed. Results indicate that the throttle governing has small contribution to response speed because the introduction of valve control cannot improve hydraulic natural frequency; the valve low-pressure coefficient has significant influence on damping ratio and speed stiffness; compared with V-PVFHS using a throttle valve, that using a speed control valve is similar to VFHS, and is less subject to variation with valve stroke with more constant damping ratios and harder stiffness, and should be a preferable scheme for V-PVFHS; the bypass throttle governing contributes to improve low speed stability, speed smooth and reduction in pressure impact at start-up and stop; the system flow is unlimited since the throttle circuit is placed in branch with small leakages. Therefore, V-PVFHS has great potential in applications requiring lower speed, larger power and higher efficient.

Online publication date: Sat, 07-Jun-2014

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Modelling, Identification and Control (IJMIC):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com