Method and apparatus for controlling rectifier
View Patent ↗A method for controlling a rectifier includes determining reactive power and active power according to sampled voltages and sampled currents of a three-phase alternating current signal, determining given active power according to a given voltage and a sampled voltage of a direct current signal, determining a target voltage vector for model predictive control according to the active power, the reactive power, the given active power, and a damping-injected Hamiltonian dissipative model, performing the model predictive control according to the target voltage vector to obtain a control signal for the rectifier, and controlling the rectifier according to the control signal.
1 . A method for controlling a rectifier configured to convert a three-phase alternating current signal into a direct current signal, the method comprising:
determining active power and reactive power according to sampled voltages and sampled currents of the three-phase alternating current signal;
determining given active power according to a given voltage and a sampled voltage of the direct current signal;
determining a target voltage vector for model predictive control according to the active power, the reactive power, the given active power, and a damping-injected Hamiltonian dissipative model;
performing the model predictive control according to the target voltage vector, to obtain a control signal for the rectifier; and
controlling the rectifier according to the control signal.
2 . The method according to claim 1 , wherein determining the target voltage vector for the model predictive control according to the active power, the reactive power, the given active power, and the damping-injected Hamiltonian dissipative model comprises:
determining a d-axis component and a q-axis component of the target voltage vector according to the active power, the reactive power, the given active power, and the damping-injected Hamiltonian dissipative model; and
transforming the d-axis component and the q-axis component of the target voltage vector into an α-axis component and a β-axis component of the target voltage vector through inverse Park transformation.
3 . The method according to claim 2 , wherein the d-axis component V d and the q-axis component V q of the target voltage vector are respectively:
V
d
=
E
m
-
2
3
L
g
P
*
E
m
+
2
3
ω
L
g
Q
E
m
-
2
3
R
g
P
*
E
m
-
2
3
R
i
(
P
*
-
P
)
E
m
,
and
V
q
=
-
2
3
L
g
Q
*
E
m
-
2
3
ω
L
g
P
E
m
-
2
3
R
g
Q
*
E
m
-
2
3
R
i
(
Q
*
-
Q
)
E
m
,
wherein
E
m
=
E
α
2
+
E
β
2
,
E α and E β are voltages of an orthogonal stationary coordinate system, R i is injected damping, P* is the given active power, P is the active power, Q* is reactive power given, Q is the reactive power, ω is an angular frequency of the three-phase alternating current signal, L g is a three-phase alternating current reactor inductance value of the three-phase alternating current signal, and R g is a three-phase alternating current reactor resistance value of the three-phase alternating current signal.
4 . The method according to claim 1 , wherein performing the model predictive control according to the target voltage vector, to obtain the control signal for the rectifier, comprises:
determining a voltage vector closest to the target voltage vector; and
using a control signal corresponding to the voltage vector closest to the target voltage vector as the control signal for the rectifier.
5 . The method according to claim 4 , wherein the control signal for the rectifier satisfies:
S opt =argmin s ( V α p ( S )− V α ) 2 +( V β p ( S )− V β ) 2 ,
wherein S represents the control signal, V α p (S) and I β p (S) are functions of S,
(
V
α
p
(
S
)
V
β
p
(
S
)
)
=
2
3
(
1
-
1
2
-
1
2
0
3
2
-
3
2
)
SV
dc
,
S
=
(
S
a
S
b
S
c
)
,
S
x
∈
{
0
,
1
}
,
x
=
{
a
,
b
,
c
}
,
and V α and V β are an α-axis component and a β-axis component of the target voltage vector.
6 . The method according to claim 1 , wherein determining the active power and the reactive power according to the sampled voltages and the sampled currents of the three-phase alternating current signal comprises:
transforming the sampled voltages and the sampled currents of the three-phase alternating current signal into orthogonal stationary coordinate system voltages and orthogonal stationary coordinate system currents through Clark transformation; and
determining the active power and the reactive power according to the orthogonal stationary coordinate system voltages and the orthogonal stationary coordinate system currents.
7 . The method according to claim 6 , wherein the active power P and the reactive power Q are respectively:
P=E α *I α +E β *I β , Q=E β *I α −E α *I β
wherein E α and E β are the orthogonal stationary coordinate system voltages; and I α and I β are the orthogonal stationary coordinate system currents.
8 . The method according to claim 1 , wherein determining the given active power according to the given voltage and the sampled voltage of the direct current signal comprises:
determining the given active power according to the given voltage and the sampled voltage of the direct current signal, and a proportional integral controller.
9 . The method according to claim 8 , wherein the given active power is an output of the proportional integral controller, and a proportional integral transfer function of the proportional integral controller is:
F
(
s
)
=
K
p
+
K
i
s
wherein an input of the proportional integral controller is V* dc −V dc , and V* dc and V dc are respectively the given voltage and the sampled voltage of the direct current signal; and K p and K i are respectively a proportional gain and an integral gain.
10 . A non-transitory computer-readable storage medium, storing a computer program, and the computer program is configured to cause a processor to execute the method according to claim 1 .
11 . An apparatus for controlling a rectifier configured to convert a three-phase alternating current signal into a direct current signal, the apparatus comprising:
an acquiring module configured to acquire sampled voltages and sampled currents of the three-phase alternating current signal and a given voltage and a sampled voltage of the direct current signal;
a processing module configured to:
determine active power and reactive power according to the sampled voltages and the sampled currents of the three-phase alternating current signal;
determine given active power according to the given voltage and the sampled voltage of the direct current signal;
determine a target voltage vector for model predictive control according to the active power, the reactive power, the given active power, and a damping-injected Hamiltonian dissipative model; and
perform the model predictive control according to the target voltage vector, to obtain a control signal for the rectifier; and
a control module configured to control the rectifier according to the control signal.
12 . The apparatus according to claim 11 , wherein the processing module is configured to:
determine a d-axis component and a q-axis component of the target voltage vector according to the active power, the reactive power, the given active power, and the damping-injected Hamiltonian dissipative model; and
transform the d-axis component and the q-axis component of the target voltage vector into an α-axis component and a β-axis component of the target voltage vector according to inverse Park transformation.
13 . The apparatus according to claim 11 , wherein an α-axis component and a β-axis component of the target voltage vector are respectively:
V
d
=
E
m
-
2
3
L
g
P
*
E
m
+
2
3
ω
L
g
Q
E
m
-
2
3
R
g
P
*
E
m
-
2
3
R
i
(
P
*
-
P
)
E
m
,
and
V
q
=
-
2
3
L
g
Q
*
E
m
-
2
3
ω
L
g
P
E
m
-
2
3
R
g
Q
*
E
m
-
2
3
R
i
(
Q
*
-
Q
)
E
m
,
wherein
E
m
=
E
α
2
+
E
β
2
,
E α and E β are orthogonal stationary coordinate system voltages, R i is injected damping, P* is the given active power, P is the active power, Q* is given reactive power, Q is the reactive power, ω is an angular frequency of the three-phase alternating current signal, L g is a three-phase alternating current reactor inductance value of the three-phase alternating current signal, and R g is a three-phase alternating current reactor resistance value of the three-phase alternating current signal.
14 . The apparatus according to claim 11 , wherein the processing module is configured to:
determine a voltage vector closest to the target voltage vector; and
use a control signal corresponding to the voltage vector closest to the target voltage vector as the control signal for the rectifier.
15 . The apparatus according to claim 14 , wherein the control signal for the rectifier satisfies:
S opt =argmin s ( V α β ( S )− V α ) 2 +( V β p ( S )− V β ) 2 ,
wherein S represents the control signal, V α p (S) and V β p (S) are functions of S,
(
V
α
p
(
S
)
V
β
p
(
S
)
)
=
2
3
(
1
-
1
2
-
1
2
0
3
2
-
3
2
)
SV
dc
,
S
=
(
S
a
S
b
S
c
)
,
S
x
∈
{
0
,
1
}
,
x
=
{
a
,
b
,
c
}
,
and V α and V β are an α-axis component and a β-axis component of the target voltage vector.
16 . The apparatus according to claim 11 , wherein the processing module is configured to:
transform the sampled voltages and the sampled currents of the three-phase alternating current signal into orthogonal stationary coordinate system voltages and orthogonal stationary coordinate system currents through Clark transformation; and
determine the active power and the reactive power according to the orthogonal stationary coordinate system voltages and the orthogonal stationary coordinate system currents.
17 . The apparatus according to claim 16 , wherein the active power P and the reactive power Q are respectively:
P=E α *I α +E β *Q=E β *I α −E α *I β
wherein E α and E β are the orthogonal stationary coordinate system voltages; and I α and I β are the orthogonal stationary coordinate system currents.
18 . The apparatus according to claim 11 , wherein the processing module is configured to:
determine the given active power according to the given voltage and the sampled voltage of the direct current signal, and a proportional integral controller.
19 . The apparatus according to claim 18 , wherein the given active power is an output of the proportional integral controller, and a proportional integral transfer function of the proportional integral controller is:
F
(
s
)
=
K
p
+
K
i
s
wherein an input of the proportional integral controller is V* dc −V dc , and V* dc and V dc are respectively the given voltage and the sampled voltage of the direct current signal; and K p and K i are respectively a proportional gain and an integral gain.