Modelling and analysis of hydraulic step-down switching converters

Authors

  • Victor J. De Negri Department of Mechanical Engineering, LASHIP, Federal University of Santa Catarina, Trindade, Florianópolis, SC 88040-900, Brazil;
  • Marcos P. Nostrani Department of Mechanical Engineering, LASHIP, Federal University of Santa Catarina, Trindade, Florianópolis, SC 88040-900, Brazil
  • Pengfei Wang Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK http://orcid.org/0000-0001-5897-0569
  • D. Nigel Johnston Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK
  • Andrew Plummer Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK

DOI:

https://doi.org/10.1080/14399776.2015.1067482

Keywords:

digital hydraulics, hydraulic switching converter, hydraulic valve, PWM switched valve

Abstract

In this study, a steady state analysis of step-down converter systems, considering the load losses in the inertance tube and switched valve, is presented. The model describes the behaviour of the average load pressure as a function of the pulse-width modulated duty cycle. The steady state expressions for the load flow rate, high and low supply flow rates, and system efficiency are also discussed. A system prototype was developed and tested to evaluate the model accuracy. The system parameters (e.g. tube diameter and length and switching frequency) were analysed to predict the best system configuration. The study describes how the system efficiency is influenced by these parameters. The model presented allows the ideal parameter combination for maximum efficiency to be determined. It can be used for the preliminary design of switching converters, and a further time or frequency analysis can be performed for system optimization.

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Author Biographies

Victor J. De Negri, Department of Mechanical Engineering, LASHIP, Federal University of Santa Catarina, Trindade, Florianópolis, SC 88040-900, Brazil;

Victor J. De Negri received his D. Eng. degree in 1996, from the Federal University of Santa Catarina (UFSC). In 2010 he took a 7-month sabbatical at PTMC, University of Bath, UK. He has been a Professor at the Mechanical Engineering Department at UFSC since 1995. He is currently the Head of the Laboratory of Hydraulic and Pneumatic Systems (LASHIP). His interest areas include hydraulic components, power generating plants, mobile hydraulics, pneumatic systems and positioning systems.

Marcos P. Nostrani, Department of Mechanical Engineering, LASHIP, Federal University of Santa Catarina, Trindade, Florianópolis, SC 88040-900, Brazil

Marcos P. Nostrani is a Master’s Student in the Department of Mechanical Engineering at the Federal University of Santa Catarina (UFSC). His current research is in digital hydraulic systems based on high speed switching valves applied in wind turbines.

Pengfei Wang, Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK

Pengfei Wang was a Research Officer in the Department of Mechanical Engineering at the University of Bath. His PhD was also awarded at the same university on hardware in the loop testing of continuously variable transmission (CVT). His research covered fluid power systems like power-assisted steering systems, CVTs, among others.

D. Nigel Johnston, Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK

D. Nigel Johnston is a Senior Lecturer in the Department of Mechanical Engineering at the University of Bath, and teaches computer programming, simulation, numerical analysis and fluid power. His PhD was for research into fluid-borne noise characteristics in hydraulic systems. This work resulted in a new ISO Standard for pump fluid-borne noise testing (ISO 10767-1: 1996). His current research interests include: modelling of the dynamic behaviour of pumps, pipelines and valves, noise in fluid power systems, valve stability, vehicle hydraulics including power-assisted steering systems, flow and pressure transients in aircraft fuel systems.

Andrew Plummer, Department of Mechanical Engineering, PTMC, University of Bath, Claverton Down, Bath BA27AY, UK

from the University of Bath in 1991, for research into adaptive control of electrohydraulic systems. He has worked for Rediffusion Simulation on flight simulator control systems, as a lecturer at the University of Leeds, and as R&D manager for Instron. Now Professor of Machine Systems at the University of Bath, and Director of the Centre for Power Transmission and Motion Control.

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Published

2018-12-28

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