Behavioural prediction of hydraulic step-up switching converters

Authors

  • Victor J. De Negri Department of Mechanical Engineering, LASHIP, Federal University of Santa Catarina, Trindade, Florianópolis, SC 88040-900, Brazil
  • Pengfei Wang Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, UK
  • Andrew Plummer Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, UK
  • D. Nigel Johnston Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, UK

DOI:

https://doi.org/10.1080/14399776.2014.882057

Keywords:

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

Abstract

In this paper the fundamental principles of energy-conservative hydraulic control based on the fluid inertance principle are discussed and a detailed analysis of step-up switched-inertance control is presented. A non-loss system comprising an inertance tube and switching valve is modelled and its operational curves are presented as a reference for an ideal behaviour. Considering the load loss at both the tube and the PWM switched valve, a linear mathematical model for the step-up switched-inertance hydraulic system is presented which describes the pressure response as a function of the PWM duty cycle. Mathematical expressions of the flow rates through the tube and the supply and return ports as well as the system efficiency are also presented. A system prototype is evaluated on a test rig and the experimental data compared with the theoretical results, demonstrating the model accuracy. The proposed model simplifies the analysis process for step-up switching converters and thus their restrictions and potential can be investigated more quickly.

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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 Juliano De Negri received his DEng 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 Department and 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.

Pengfei Wang, Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, 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 such as power-assisted steering systems and CVTs, among others.

Andrew Plummer, Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, 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 such as power-assisted steering systems and CVTs, among others.

D. Nigel Johnston, Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA 27AY, UK

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 tability; vehicle hydraulics including power-assisted steering systems; and flow and pressure transients in aircraft fuel systems.

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Published

2014-03-01

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