Input vector set for position detection of PM motors

Patent metadata

Field	Value
Publication number	US-11070155-B2
Application number	US-202016740517-A
Country	US
Kind code	B2
Filing date	Jan 13, 2020
Priority date	Sep 24, 2014
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A method of determining angular position (θ) of a rotor of an N-phase permanent magnet motor (PMM). A processor having an associated stored angular position determination (APD) algorithm is programmed to implement the algorithm to cause an associated motor controller to execute steps including forcing one vector at a time a phase vector set of current or voltage vectors to stator terminals of windings for the N-phases a positive and negative magnitude vector, wherein the vector magnitude is sufficiently small to not move the rotor, and a time duration for the forcing current or voltage vectors is essentially constant. The resulting stator current or voltage levels are measured for each current or voltage vector. An N-dimension current vector or voltage vector is generated from superposition of the resulting stator current levels or resulting stator voltage levels. The N-dimension current vector or voltage vector is used to determine angular position.

First claim

The invention claimed is:

1. A motor control system comprising:
an analog-to-digital converter (ADC) for receiving N-phase measurements from stator windings;
a processor wherein the processor receives digital values of the N-phase measurements from the ADC; wherein the processor is configured to generate N-dimension voltage vectors from superposition of selected ones of the digital values of the N-phase measurements;
a program memory wherein the program memory includes an angular position determination (APD) algorithm; wherein APD algorithm determines the angular position based on the N-dimension voltage vectors;
a pulse-width modulation (PWM) driver wherein the PWM driver generates a set of input vectors;
an APD controller for controlling a signal generator; wherein the signal generator generates signals for the PWM driver.

2. The motor control system of claim 1 , wherein the N-dimension voltage vectors are fundamental vectors.

3. The motor control system claim 1 , wherein the angular position determination is determined by:

θ
=

tan

-
1

⁡

(

-

∑

n
=
1

N

⁢

⁢

x
n

·

sin
⁡

(

2
⁢

π
·

(

n
-
1

)

N

)

∑

n
=
1

N

⁢

⁢

x
n

·

cos
⁡

(

2
⁢

π
·

(

n
-
1

)

N

)

)

wherein said x n is stator voltage level.

4. The motor control system of claim 1 , wherein the selected ones of the digital values of the N-phase measurements are identified for each of the N-phase measurements by determining a largest absolute value of a difference between stator voltage levels from the positive magnitude vector and the negative magnitude vector.

5. The motor control system claim 1 , wherein the motor control system includes a controller for controlling direct current.

6. The motor control system claim 1 , wherein the motor control system includes a controller for controlling quadrature current.

7. A motor control system comprising:
an analog-to-digital converter (ADC) for receiving N-phase measurements from stator windings;
a processor wherein the processor receives digital values of the N-phase measurements from the ADC; wherein the processor is configured to generate N-dimension current vectors from superposition of selected ones of the digital values of the N-phase measurements;
a program memory wherein the program memory includes an angular position determination (APD) algorithm; wherein APD algorithm determines the angular position based on the N-dimension current vectors;
a pulse-width modulation (PWM) driver wherein the PWM driver generates a set of input vectors;
an APD controller for controlling a signal generator; wherein the signal generator generates signals for the PWM driver.

8. The motor control system of claim 7 , wherein the N-dimension current vectors are fundamental vectors.

9. The motor control system claim 7 , wherein the angular position determination is determined by:

θ
=

tan

-
1

⁡

(

-

∑

n
=
1

N

⁢

⁢

x
n

·

sin
⁡

(

2

Assignees

• Texas Instruments Inc

Inventors

• Thomas Eric James
• Magee David Patrick

Classifications

• H02P21/18 Primary

  Estimation of position or speed · CPC title

• H02P21/24 Primary

  Vector control not involving the use of rotor position or rotor speed sensors · CPC title

• H02P25/03

  with brushless excitation · CPC title

• H02P27/08

  with pulse width modulation · CPC title