Method and device for driving motors
A method and device for driving a motor by synchronous calculation of sampled phase current and phase voltage, including: sampling three-phase current of a motor to obtain a current sampling value, and obtaining an instruction voltage or a sample voltage as a voltage sampling value; and performing synchronous conversion on the current sampling value and the voltage sampling value to obtain a fundamental wave voltage at a current sampling time to keep a current vector and a voltage vector input into a flux observer synchronous.
1. A method, comprising:
sampling a three-phase current of a motor to obtain a current sampling value and a voltage sampling value, wherein the voltage sampling value is a command voltage or a sampled voltage; and
performing synchronous conversion on the current sampling value and the voltage sampling value to obtain a fundamental voltage at a current sampling time to keep a current vector and a voltage vector synchronous, wherein the current vector and the voltage vector are input to a flux observer.
2. The method of claim 1 , wherein the synchronous conversion is performed on the current sampling value and the voltage sampling value, including:
taking an intermediate time of two adjacent pulse width modulation (PWM) carrier cycles as the current sampling time, and synchronously converting a voltage at a prior time before the current sampling time and/or a voltage at a subsequent time after the current sampling time into a voltage at the current sampling time; or
taking a time between two adjacent PWM carrier peaks as a reference synchronization time, and synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time.
3. The method of claim 2 , wherein the voltage at the prior time before the current sampling time is a voltage corresponding to a peak of a prior PWM carrier wave, and the voltage at the subsequent time after the current sampling time is a voltage corresponding to a peak of a subsequent PWM carrier wave.
4. The method of claim 3 , wherein synchronously converting the voltage at the prior time before the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
cos
θ
Δ
-
V
1
β
sin
θ
Δ
V
1
β
cos
θ
Δ
+
V
1
α
sin
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V tα and V 1β represent voltages at the prior time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t Δ ,ω e represents an electrical angular frequency, and t Δ represents a duration from the prior time to the current sampling time;
wherein synchronously converting the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
2
α
cos
θ
Δ
+
V
2
β
sin
θ
Δ
V
2
β
cos
θ
Δ
-
V
2
α
sin
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V 2α and V 2β represent voltages at the subsequent time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t Δ ,ω e represents an electrical angular frequency, and t Δ represents a duration from the current sampling time to the subsequent time; and
wherein synchronously converting the voltage at the prior time before the current sampling time and the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
+
V
2
α
2
cos
θ
Δ
+
V
2
β
-
V
1
β
2
sin
θ
Δ
V
1
β
+
V
2
β
2
cos
θ
Δ
+
V
1
α
-
V
2
α
2
sin
θ
Δ
]
.
5. The method of claim 2 , wherein synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time includes:
determining an electrical quantity 1 at a time t Δ1 before the reference synchronization time t x and an electrical quantity 2 at a time t Δ2 after the reference synchronization time t x ;
if the electrical quantity 1 at the time t Δ1 is synchronously converted into an electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
-
X
1
β
sin
θ
Δ
1
X
1
β
cos
θ
Δ
1
+
X
1
α
sin
θ
Δ
1
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in a two-phase stationary coordinate system, respectively, X 1α and X 1β represent electrical quantities at the time t Δ1 in the two-phase stationary coordinate system, respectively, θ Δ1 =ω e t Δ1 , and ω e represents an electrical angular frequency;
if the electrical quantity 2 at the time t Δ2 is synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
X
2
β
cos
θ
Δ
2
-
X
2
α
sin
θ
Δ
2
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in the two-phase stationary coordinate system, respectively, X 2α and X 2β represent electrical quantities at the time t Δ2 in the two-phase stationary coordinate system, respectively, θ Δ2 =ω e t Δ2 , and ω e represents an electrical angular frequency; and
if the electrical quantity 1 at the time t Δ1 and the electrical quantity 2 at the time t Δ2 are synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
+
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
-
X
1
β
sin
θ
Δ
1
2
X
1
β
cos
θ
Δ
1
+
X
2
β
cos
θ
Δ
2
+
X
1
α
sin
θ
Δ
1
-
X
2
α
sin
θ
Δ
2
2
]
.
6. A non-transitory computer-readable storage medium storing one or more computer programs comprising instructions that, when executed by an electronic device, cause the electronic device to:
sample a three-phase current of a motor to obtain a current sampling value and a voltage sampling value, wherein the voltage sampling value is a command voltage or a sampled voltage; and
perform synchronous conversion on the current sampling value and the voltage sampling value to obtain a fundamental voltage at a current sampling time to keep a current vector and a voltage vector synchronous, wherein the current vector and the voltage vector are input to a flux ob server.
7. The computer-readable storage medium of claim 6 , wherein the synchronous conversion is performed on the current sampling value and the voltage sampling value, including:
taking an intermediate time of two adjacent pulse width modulation (PWM) carrier cycles as the current sampling time, and synchronously converting a voltage at a prior time before the current sampling time and/or a voltage at a subsequent time after the current sampling time into a voltage at the current sampling time; or
taking a time between two adjacent PWM carrier peaks as a reference synchronization time, and synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time.
8. The computer-readable storage medium of claim 7 , wherein the voltage at the prior time before the current sampling time is a voltage corresponding to a peak of a prior PWM carrier wave, and the voltage at the subsequent time after the current sampling time is a voltage corresponding to a peak of a subsequent PWM carrier wave.
9. The computer-readable storage medium of claim 8 , wherein synchronously converting the voltage at the prior time before the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
cos
θ
Δ
-
V
1
β
cos
θ
Δ
V
1
β
cos
θ
Δ
+
V
1
α
cos
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V 1α and V 1β represent voltages at the prior time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t Δ , ω e represents an electrical angular frequency, and t A represents a duration from the prior time to the current sampling time;
wherein synchronously converting the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
2
α
cos
θ
Δ
+
V
2
β
sin
θ
Δ
V
2
β
cos
θ
Δ
-
V
2
α
sin
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V 2α and V 2β represent voltages at the subsequent time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t Δ , ω e represents an electrical angular frequency, and t Δ represents a duration from the current sampling time to the subsequent time; and
wherein synchronously converting the voltage at the prior time before the current sampling time and the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
+
V
2
α
2
cos
θ
Δ
+
V
2
β
-
V
1
β
2
sin
θ
Δ
V
1
β
+
V
2
β
2
cos
θ
Δ
+
V
1
α
-
V
2
α
2
sin
θ
Δ
]
.
10. The computer-readable storage medium of claim 7 , wherein synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time includes:
determining an electrical quantity 1 at a time t Δ1 before the reference synchronization time t x and an electrical quantity 2 at a time t Δ2 after the reference synchronization time t x ;
if the electrical quantity 1 at the time t Δ1 is synchronously converted into an electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
-
X
1
β
sin
θ
Δ
1
X
1
β
cos
θ
Δ
1
+
X
1
α
sin
θ
Δ
1
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in a two-phase stationary coordinate system, respectively, X 1α and X 1β represent electrical quantities at the time t Δ1 in the two-phase stationary coordinate system, respectively, θ Δ1 =ω e t Δ1 , and ω e represents an electrical angular frequency;
if the electrical quantity 2 at the time t Δ2 is synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
X
2
β
cos
θ
Δ
2
-
X
2
α
sin
θ
Δ
2
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in the two-phase stationary coordinate system, respectively, X 2α and X 2β represent electrical quantities at the time t Δ2 in the two-phase stationary coordinate system, respectively, θ Δ2 =ω e t Δ2 , and ω e represents an electrical angular frequency; and
if the electrical quantity 1 at the time t Δ1 and the electrical quantity 2 at the time t Δ2 are synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
+
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
-
X
1
β
sin
θ
Δ
1
2
X
1
β
cos
θ
Δ
1
+
X
2
β
cos
θ
Δ
2
+
X
1
α
sin
θ
Δ
1
-
X
2
α
sin
θ
Δ
2
2
]
.
11. A motor driving system including one or more processors, memory, and one or more non-transitory computer programs, wherein the one or more non-transitory computer programs are stored in the memory and configured to be executed by the one or more processors, the one or more non-transitory computer programs including instructions for:
sampling a three-phase current of a motor to obtain a current sampling value and a voltage sampling value, wherein the voltage sampling value is a command voltage or a sampled voltage; and
performing synchronous conversion on the current sampling value and the voltage sampling value to obtain a fundamental voltage at a current sampling time to keep a current vector and a voltage vector synchronous, wherein the current vector and the voltage vector are input to a flux observer.
12. The motor driving system of claim 11 , wherein the synchronous conversion is performed on the current sampling value and the voltage sampling value, including:
taking an intermediate time of two adjacent pulse width modulation (PWM) carrier cycles as the current sampling time, and synchronously converting a voltage at a prior time before the current sampling time and/or a voltage at a subsequent time after the current sampling time into a voltage at the current sampling time; or
taking a time between two adjacent PWM carrier peaks as a reference synchronization time, and synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time.
13. The motor driving system of claim 12 , wherein the voltage at the prior time before the current sampling time is a voltage corresponding to a peak of a prior PWM carrier wave, and the voltage at the subsequent time after the current sampling time is a voltage corresponding to a peak of a subsequent PWM carrier wave.
14. The motor driving system of claim 13 , wherein synchronously converting the voltage at the prior time before the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
cos
θ
Δ
-
V
1
β
sin
θ
Δ
V
1
β
cos
θ
Δ
+
V
1
α
sin
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V 1α and V 1β represent voltages at the prior time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t Δ , ω e represents an electrical angular frequency, and t Δ represents a duration from the prior time to the current sampling time;
wherein synchronously converting the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
2
α
cos
θ
Δ
+
V
2
β
sin
θ
Δ
V
2
β
cos
θ
Δ
-
V
2
α
sin
θ
Δ
]
,
where V xα and V xβ represent voltages at the current sampling time in the two-phase stationary coordinate system, respectively, V 2α and V 2β represent voltages at the subsequent time in the two-phase stationary coordinate system, respectively, θ Δ =ω e t 66 , ω e represents an electrical angular frequency, and t Δ represents a duration from the current sampling time to the subsequent time; and
wherein synchronously converting the voltage at the prior time before the current sampling time and the voltage at the subsequent time after the current sampling time into the voltage at the current sampling time is performed according to the following formula:
[
V
x
α
V
x
β
]
=
[
V
1
α
+
V
2
α
2
cos
θ
Δ
+
V
2
β
-
V
1
β
2
sin
θ
Δ
V
1
β
+
V
2
β
2
cos
θ
Δ
+
V
1
α
-
V
2
α
2
sin
θ
Δ
]
.
15. The motor driving system of claim 12 , wherein synchronously converting the current sampling value and the voltage sampling value according to the reference synchronization time includes:
determining an electrical quantity 1 at a time t Δ1 before the reference synchronization time t x and an electrical quantity 2 at a time t Δ2 after the reference synchronization time t x ;
if the electrical quantity 1 at the time t Δ1 is synchronously converted into an electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
-
X
1
β
sin
θ
Δ
1
X
1
β
cos
θ
Δ
1
+
X
1
α
sin
θ
Δ
1
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in a two-phase stationary coordinate system, respectively, X 1α and X 1β represent electrical quantities at the time t Δ1 in the two-phase stationary coordinate system, respectively, θ Δ1 =ω e t Δ1 , and ω e represents an electrical angular frequency;
if the electrical quantity 2 at the time t Δ2 is synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
X
2
β
cos
θ
Δ
2
-
X
2
α
sin
θ
Δ
2
]
,
where X xα and X xβ represent electrical quantities at the reference synchronization time in the two-phase stationary coordinate system, respectively, X 2α and W 2β represent electrical quantities at the time t Δ2 in the two-phase stationary coordinate system, respectively, θ Δ2 =ω e t Δ2 , and ω e represents an electrical angular frequency; and
if the electrical quantity 1 at the time t Δ1 and the electrical quantity 2 at the time t Δ2 are synchronously converted into the electrical quantity at the reference synchronization time t x , the synchronous conversion is performed according to the following formula:
[
X
x
α
X
x
β
]
=
[
X
1
α
cos
θ
Δ
1
+
X
2
α
cos
θ
Δ
2
+
X
2
β
sin
θ
Δ
2
-
X
1
β
sin
θ
Δ
1
2
X
1
β
cos
θ
Δ
1
+
X
2
β
cos
θ
Δ
2
+
X
1
α
sin
θ
Δ
1
-
X
2
α
sin
θ
Δ
2
2
]
.