US 9,518,578 B2Granted

System for controlling a resonant linear compressor piston, method for controlling a resonant linear compressor piston, and resonant linear compressor

AssigneeWhirlpool S.A.; Fundacao Universidade de Estado de Santa Catarina—UDESC

InventorsPaulo Sergio Dainez, José de Oliveira, Ademir Nied

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Abstract

A control method and a system for controlling the piston of a resonant linear compressor including at least one electronic control unit, the electronic control unit including at least one observing electronic circuit and at least one control circuit associated to each other. The observing electronic circuit is configured for: measuring at least one electric magnitude of the electric motor; estimating at least one set of electric parameters and at least one set of mechanical parameters of the resonant linear compressor; and estimating and providing at least one control parameter of the system for the control circuit based on the measured electric magnitude measured and on the estimated set of electric and mechanical parameters. The control circuit is configured for actuating the electric motor from the at least one control parameter.

Claims22

Dependent claims

A control system for controlling a piston (1) of a resonant linear compressor (100), the resonant linear compressor (100) being an integral part of a cooling circuit, the resonant linear compressor (100) comprising a cylinder (2), a head (3), an electric motor and a spring, the cylinder (2) housing the piston (1) operatively;

the control system comprising an electronic control unit (15), the electronic control unit (15) comprising an observing electronic circuit (20) and a control circuit (30), associated to each other;
the electronic control unit (15) being electrically associated to the electric motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for measuring at least one electric magnitude of the electric motor of the resonant linear compressor (100), the at least one electric magnitude of the electric motor of the resonant linear compressor (100) comprising at least an operation current value (im) of the motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating at least one set of electric parameters of the motor of the resonant linear compressor (100) and at least one set of mechanical parameters of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating and providing at least one control parameter (Pc) of the system for the control circuit (30) from the at least one electric magnitude measured and sets of electric and mechanical parameters calculated;
the control circuit (30) being configured for actuating the electric motor of the resonant linear compressor (100) from the at least one control parameter (Pc), the at least one control parameter (Pc) comprising:
(i) at least one maximum displacement (DMAX) of the piston (1) of the compressor (100);
and, (ii) a piston velocity (Ve(t)) of the compressor (100);
wherein the set of electric parameters is calculated from an electric mathematical model of the resonant linear compressor (100), the electric mathematic model of the linear compressor (100) being defined on the basis of an electric circuit RL in series with a voltage source and equated through the following equation:
VENT(t)=VR(ie(t))+VL(ie(t))+VMT(ve(t))
wherein:
VR(ie(t))=R·ie(t);
resistance voltage [V];
V
L
⁡
(
i
e
⁡
(
t
)
)
=
L
·
ⅆ
i
e
⁡
(
t
)
ⅆ
t
;
inductor
⁢
⁢
voltage
⁢
[
V
]
;
VMT(ve(t))=KMT·ve(t);
induced voltage of the motor or back-EMF [V];
VENT(t);
feed voltage [V];
R;
electric resistance of the motor of the compressor
L;
inductance of the motor of the compressor (100)
KMT;
force and voltage Constant of the motor
ve(t);
calculated piston velocity
ie(t);
estimated or calculated current of the motor.

57 more elements

the control system comprising an electronic control unit (15), the electronic control unit (15) comprising an observing electronic circuit (20) and a control circuit (30), associated to each other;
the electronic control unit (15) being electrically associated to the electric motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for measuring at least one electric magnitude of the electric motor of the resonant linear compressor (100), the at least one electric magnitude of the electric motor of the resonant linear compressor (100) comprising at least an operation current value (im) of the motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating at least one set of electric parameters of the motor of the resonant linear compressor (100) and at least one set of mechanical parameters of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating and providing at least one control parameter (Pc) of the system for the control circuit (30) from the at least one electric magnitude measured and sets of electric and mechanical parameters calculated;
the control circuit (30) being configured for actuating the electric motor of the resonant linear compressor (100) from the at least one control parameter (Pc), the at least one control parameter (Pc) comprising:
(i) at least one maximum displacement (DMAX) of the piston (1) of the compressor (100);
and, (ii) a piston velocity (Ve(t)) of the compressor (100);
wherein the set of mechanical parameters is calculated from a mechanical mathematical model of the resonant linear compressor (100), the mechanical mathematical model of the linear compressor (100) being defined on the basis of a mass/spring mechanical system according to the following equation:
m
·
ⅆ
2
⁢
d
e
⁡
(
t
)
ⅆ
t
2
=
F
MT
⁡
(
i
e
⁡
(
t
)
)
-
F
ML
⁡
(
d
e
⁡
(
t
)
)
-
F
AM
⁡
(
v
e
⁡
(
t
)
)
-
F
G
⁡
(
d
e
⁡
(
t
)
)
wherein:
FMT(ie(t))=KMT·ie(t);
motor force [N];
FML(de(t))=KML·de(t);
spring force [N];
FAM (ve(t))=KAM·ve(t);
dampening force [N];
FG(d(t));
gas-pressure force in the cylinder [N];
KMT;
motor constant
KML;
spring constant
KAM;
first dampening constant
m;
mass of the moveable part
ve(t);
piston velocity;
de(t);
piston displacement;
ie(t);
calculated current of the motor.

91 more elements

the control system comprising an electronic control unit (15), the electronic control unit (15) comprising an observing electronic circuit (20) and a control circuit (30), associated to each other;
the electronic control unit (15) being electrically associated to the electric motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for measuring at least one electric magnitude of the electric motor of the resonant linear compressor (100), the at least one electric magnitude of the electric motor of the resonant linear compressor (100) comprising at least an operation current value (im) of the motor of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating at least one set of electric parameters of the motor of the resonant linear compressor (100) and at least one set of mechanical parameters of the resonant linear compressor (100);
the observing electronic circuit (20) being configured for calculating and providing at least one control parameter (Pc) of the system for the control circuit (30) from the at least one electric magnitude measured and sets of electric and mechanical parameters calculated;
the control circuit (30) being configured for actuating the electric motor of the resonant linear compressor (100) from the at least one control parameter (Pc), the at least one control parameter (Pc) comprising:
(i) at least one maximum displacement (DMAX) of the piston (1) of the compressor (100);
and, (ii) a piston velocity (Ve(t)) of the compressor (100);
wherein the set of electric parameters and set of mechanical parameters, when combined, define a set of electromechanical parameters, the electromechanical parameters being equated through the following matrix equation:
{dot over (x)}(t)=A·x(t)+B·u(t)+F·g(t)
y(t)=C·x(t)
wherein:
x(t)=(ve(t) de(t) ie(t))T;
state vector
y(t)=ie(t);
system output
u(t)=VENT(t);
feed voltage [V]
g(t)=FG(d(t));
gas-pressure force in the cylinder [N];
A
=
(
-
K
AM
m
-
K
ML
m
K
MT
m
1
0
0
-
K
MT
L
0
-
R
L
)
;
dynamic
⁢
⁢
matrix
⁢
⁢
of
⁢
⁢
the
⁢
⁢
system
B
=
(
0
0
1
L
)
T
,
;
feed
⁢
⁢
input
⁢
⁢
vector
F
=
(
1
m
0
0
)
T
,
;
pressure
⁢
⁢
input
⁢
⁢
vector
C=(0 0 1);
output vector
KMT;
motor constant
KML;
spring constant
KAM;
first dampening constant
R;
electric resistance of the compressor
L;
inductance of the motor of the compressor (100)
m;
mass of the moveable part
ve(t);
piston velocity;
de(t);
piston displacement;
ie(t);
calculated current of the motor.

113 more elements

A control method for controlling a piston (1) of a resonant linear compressor (100), the resonant linear compressor (100) being an integral part of a cooling circuit and comprising an electric motor, the electric motor being associated to an electronic control unit (15), the control method comprising the following steps:

a) measuring, by means of an electronic control unit (15), at least one electric magnitude of the electric motor of the resonant linear compressor (100), the at least one electric magnitude of the electric motor of the resonant linear compressor (100) comprising at least an operation current value (im) of the motor of the resonant linear compressor (100);
b) calculating, by means of the electronic control unit (15), at least one set of electric parameters of the motor of the resonant linear compressor (100) and at least one set of mechanical parameters of the resonant linear compressor (100);
c) calculating, by means of the electronic control unit (15), at least one control parameter (Pc) from the at least one electric magnitude measured and set of electric and mechanical parameters calculated;
d) actuating, by means of the electronic control unit (15), the electric motor of the resonant linear compressor (100) from the at least one control parameters (Pc), the at least one control parameter (Pc) comprising:
(i) at least one maximum displacement (DMAX) of the piston (1) of the compressor (100);
and, (ii) a piston velocity (Ve(t)) of the compressor (100);
wherein the set of electric parameters and set of mechanical parameters, when combined, define a set of electromechanical parameters, the electromechanical parameters being equated through the following matrix equation:
{dot over (x)}(t)=A·x(t)+B·u(t)+F·g(t)
y(t)=C·x(t)
wherein:
x(t)=(ve(t) de(t) ie(t))T;
state vector
y(t)=ie(t);
system output
u(t)=VENT(t);
feed voltage [V]
g(t)=FG(d(t));
gas-pressure force in the cylinder [N];
A
=
(
-
K
AM
m
-
K
ML
m
K
MT
m
1
0
0
-
K
MT
L
0
-
R
L
)
;
dynamic
⁢
⁢
matrix
⁢
⁢
of
⁢
⁢
the
⁢
⁢
system
B
=
(
0
0
1
L
)
T
,
;
feed
⁢
⁢
input
⁢
⁢
vector
F
=
(
1
m
0
0
)
T
,
;
pressure
⁢
⁢
input
⁢
⁢
vector
C=(0 0 1);
output vector
KMT;
motor constant
KML;
spring constant
KAM;
first dampening constant
R;
electric resistance of the compressor
L;
inductance of the motor of the compressor (100)
m;
mass of the moveable part
ve(t);
piston velocity;
de(t);
position displacement;
ie(t);
calculated current of the motor.

111 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/696,253Filed 5 May 2011
Priority: BR 10013885 May 2010
Published: US 2013/0189119 A125 Jul 2013
Granted: 13 Dec 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

F04B 49/065
Control using electricity: and making use of computers
F04B 35/04
Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or…:…
F04B 35/045
The means being electric: using solenoids
F04B 49/06
Control , e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided…:…