US2016215770A1PendingUtilityA1
Method for operating a linear compressor
Est. expiryJan 28, 2035(~8.5 yrs left)· nominal 20-yr term from priority
F04B 35/04F04B 49/065F04B 2203/0402F04B 2203/0401F04B 2203/0409F04B 35/045
38
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Claims
Abstract
A method for operating a linear compressor is provided. The method includes supplying a motor of the linear compressor with a time varying voltage and estimating a back-EMF of the motor of the linear compressor. The method also includes determining a velocity of the motor of the linear compressor based at least in part on the back-EMF of the motor and calculating a stroke length of the motor of the linear compressor based at least in part on the velocity of the motor.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . A method for operating a linear compressor, comprising:
providing an electrical dynamic model for a motor of the linear compressor; supplying the motor of the linear compressor with a time varying voltage; estimating a back-EMF of the motor of the linear compressor during said step of supplying using at least the electrical dynamic model for the motor of the linear compressor and a robust integral of the sign of the error feedback; determining a velocity of the motor of the linear compressor based at least in part on the back-EMF of the motor from said step of estimating; and calculating a stroke length of the motor of the linear compressor based at least in part on the velocity of the motor from said step of determining.
2 . The method of claim 1 , wherein the electrical dynamic model for the motor comprises
i
t
=
v
a
L
i
-
r
i
i
L
i
-
α
x
.
L
i
where
v a is a voltage across the motor of the linear compressor;
r i is a resistance of the motor of the linear compressor;
i is a current through the motor of the linear compressor;
α is a motor force constant;
{dot over (x)} is a velocity of the motor of the linear compressor; and
L i is an inductance of the motor of the linear compressor.
3 . The method of claim 2 , further establishing a time varying current through the motor of the linear compressor during said step of supplying.
4 . The method of claim 1 , wherein the linear compressor is positioned within a refrigerator appliance.
5 . The method of claim 1 , wherein estimating the back-EMF of the motor of the linear compressor during said step of supplying using the robust integral of the sign of the error feedback comprises solving
{circumflex over ( f )}=( K 1 +1) e ( t )+∫ t 0 t [( K 1 +1) e (σ)+ K 2 sgn( e (σ))] d σ−( K 1 +1) e ( t 0 )
where
{circumflex over (f)} is an estimated back-EMF of the motor of the linear compressor;
K 1 and K 2 are real, positive gains; and
e=î−i and ė=f−{circumflex over (f)}.
6 . The method of claim 5 , said step of determining the velocity of the motor of the linear compressor comprises solving
x
.
^
=
L
i
α
f
^
where
{dot over ({circumflex over (x)})} is an estimated velocity of the motor of the linear compressor;
α is a motor force constant; and
L i is an inductance of the motor of the linear compressor.
7 . The method of claim 6 , wherein said step of calculating the stroke length of the motor of the linear compressor comprises solving
X
=
L
i
α
∫
f
^
t
=
x
^
initial
+
x
^
(
t
)
where {circumflex over (x)} is an estimated position of the motor of the linear compressor.
8 . The method of claim 1 , further comprising adjusting the time varying voltage supplied to the motor of the linear compressor in order to operate the motor of the linear compressor at a resonant frequency of the motor of the linear compressor.
9 . The method of claim 1 , wherein said steps of estimating, determining and calculating are conducted with the motor of the linear compressor sealed within a hermitic shell of the linear compressor.
10 . A method for operating a linear compressor, comprising:
supplying the motor of the linear compressor with a time varying voltage, the motor of the linear compressor disposed within a hermetic shell of the linear compressor during said step of supplying; estimating a back-EMF of the motor of the linear compressor during said step of supplying using a robust integral of the sign of the error feedback; determining a velocity of the motor of the linear compressor based at least in part on the back-EMF of the motor from said step of estimating; and calculating a stroke length of the motor of the linear compressor based at least in part on the velocity of the motor from said step of determining.
11 . The method of claim 10 , further comprising providing an electrical dynamic model for the motor of the linear compressor, the electrical dynamic model for the motor comprising
i
t
=
v
a
L
i
-
r
i
i
L
i
-
α
x
.
L
i
where
v a is a voltage across the motor of the linear compressor;
r i is a resistance of the motor of the linear compressor;
i is a current through the motor of the linear compressor;
α is a motor force constant;
{dot over (x)} is a velocity of the motor of the linear compressor; and
L i is an inductance of the motor of the linear compressor.
12 . The method of claim 11 , further establishing a time varying current through the motor of the linear compressor during said step of supplying.
13 . The method of claim 11 , the linear compressor is positioned within a refrigerator appliance.
14 . The method of claim 10 , wherein estimating the back-EMF of the motor of the linear compressor during said step of supplying using the robust integral of the sign of the error feedback comprises solving
{circumflex over ( f )}=( K 1 +1) e ( t )+∫ t 0 t [( K 1 +1) e (σ)+ K 2 sgn( e (σ))] d σ−( K 1 +1) e ( t 0 )
where
{circumflex over (f)} is an estimated back-EMF of the motor of the linear compressor;
K 1 and K 2 are real, positive gains; and
e=î−i and e=f−{circumflex over (f)}.
15 . The method of claim 14 , said step of determining the velocity of the motor of the linear compressor comprises solving
x
.
^
=
L
i
α
f
^
where
{dot over ({circumflex over (x)})} is an estimated velocity of the motor of the linear compressor;
α is a motor force constant; and
L i is an inductance of the motor of the linear compressor.
16 . The method of claim 15 , wherein said step of calculating the stroke length of the motor of the linear compressor comprises solving
X
=
L
i
α
∫
f
^
t
=
x
^
initial
+
x
^
(
t
)
where {circumflex over (x)} is an estimated position of the motor of the linear compressor.
17 . The method of claim 10 , further comprising adjusting the time varying voltage supplied to the motor of the linear compressor in order to operate the motor of the linear compressor at a resonant frequency of the motor of the linear compressor.Join the waitlist — get patent alerts
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