A typical switched inertance buck converter includes digital valves controlling the flow of fluid to the load from the pressure supply and also from the reservoir. These valves are typically located at the same position, often packaged in the form of a single three-way valve, but also sometimes in the form of a two-way high-pressure supply valve and check valve from tank. This results in the situation where attempts to increase flow boosting performance by exploiting reflected pressure waves to draw additional fluid from tank will also tend to draw additional fluid through the valve from the high-pressure supply, causing increased energy loss at the valve. This paper presents a strategy that avoids this tradeoff by locating the tank flow valve along the length of the inertance tube such that the timing of pressure waves arriving at the tank valve can be optimized separately from those arriving at the high-pressure supply valve. A simulation study is presented, in which valve placement and inertance tube resonance are optimized for flow gain or energy efficiency, with results in both cases better than a conventional system with colocated valves. Two strategies for avoiding cavitation are also presented.

References

References
1.
de Montgolfier
,
J.
,
1803
,
Note sur le bélier hydraulique et sur la manière d'en calculer les effets
,
Gille et Fils
,
Paris, France
.
2.
Brown
,
F.
,
1984
, “
On Switching Circuits for Fluid Servosystems
,”
National Conference on Fluid Power
, Chicago, IL, NFPA Milwaukee, WI, pp.
209
218
.
3.
Brown
,
F. T.
,
1987
, “
Switched Reactance Hydraulics: A New Way to Control Fluid Power
,”
National Conference on Fluid Power
, Chicago, IL, NFPA Milwaukee, WI, pp.
25
34
.
4.
Johnston
,
D. N.
,
2009
, “
A Switched Inertance Device for Efficient Control of Pressure and Flow
,”
ASME
Paper No. DSCC2009-2535.
5.
Kogler
,
H.
,
2012
,
The Hydraulic Buck Converter-Conceptual Study and Experiments
,
Trauner Verlag & Buchservice GmbH
,
Linz, Austria
.
6.
Scheidl
,
R.
,
Kogler
,
H.
, and
Winkler
,
B.
,
2012
, “
Hydraulic Switching Control–Objectives, Concepts, Challenges and Potential Applications
,”
International Conference of Hydraulics and Pneumatics
, Calimanesti-Caciulata, Romania, pp.
56
67
.
7.
Cui
,
P.
,
Burton
,
R. T.
, and
Ukrainetz
,
P. R.
,
1991
, “
Development of a High Speed On/Off Valve
,” SAE Technical Paper No. 911815.
8.
Winkler
,
B.
,
2004
, “
Development of a Fast Low-Cost Switching Valve for Big Flow Rates
,”
3rd PFNI-PhD Symposium on Fluid Power
, Terrassa, Spain, pp. 599–606.
9.
Pan
,
M.
,
Johnston
,
N.
,
Robertson
,
J.
,
Plummer
,
A.
,
Hillis
,
A.
, and
Yang
,
H.
,
2015
, “
Experimental Investigation of a Switched Inertance Hydraulic System With a High-Speed Rotary Valve
,”
ASME J. Dyn. Syst., Meas., Control
,
137
(
12
), p.
121003
.
10.
Sell
,
N. P.
,
Johnston
,
N.
,
Plummer
,
A. R.
, and
Kudzma
,
S.
,
2015
, “
Development of a Position Controlled Digital Hydraulic Valve
,”
ASME
Paper No. FPMC2015-9514.
11.
Wiens
,
T.
,
2015
, “
Analysis and Mitigation of Valve Switching Losses in Switched Inertance Converters
,”
ASME
Paper No. FPMC2015-9600.
12.
Scheidl
,
R.
, and
Hametner
,
G.
,
2003
, “
The Role of Resonance in Elementary Hydraulic Switching Control
,”
Proc. Inst. Mech. Eng., Part I
,
217
(
6
), pp.
469
480
.
13.
Wang
,
P.
,
Kudzma
,
S.
,
Johnston
,
N.
,
Plummer
,
A.
, and
Hillis
,
A.
,
2011
, “
The Influence of Wave Effects on Digital Switching Valve Performance
,”
In the Fourth Workshop on Digital Fluid Power
, Linz, Austria, pp. 10–25.
14.
Kogler
,
H.
,
Scheidl
,
R.
, and
Schmidt
,
B.
,
2015
, “
Analysis of Wave Propagation Effects in Transmission Lines Due to Digital Valve Switching
,”
ASME
Paper No. FPMC2015-9607.
15.
Johnston
,
N.
,
2012
, “
The Transmission Line Method for Modelling Laminar Flow of Liquid in Pipelines
,”
Proc. Inst. Mech. Eng., Part I
,
226
(
5
), pp.
586
597
.
16.
Pan
,
M.
,
Johnston
,
N.
,
Plummer
,
A.
,
Kudzma
,
S.
, and
Hillis
,
A.
,
2014
, “
Theoretical and Experimental Studies of a Switched Inertance Hydraulic System
,”
Proc. Inst. Mech. Eng., Part I
,
228
(
1
), pp.
12
25
.
17.
Wiens
,
T.
,
2015
, “
USask Hydraulic Models for Matlab Simscape
,” https://github.com/tkw954/usask_hyd_lib_ssc, T. Wiens, Saskatoon, SK, Canada.
18.
Shampine
,
L. F.
, and
Reichelt
,
M. W.
,
1997
, “
The MATLAB ODE Suite
,”
SIAM J. Sci. Comput.
,
18
(
1
), pp.
1
22
.
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