Motor parameter tracking method and motor parameter tracking system

Patent metadata

Field	Value
Publication number	US-11211888-B2
Application number	US-202016993304-A
Country	US
Kind code	B2
Filing date	Aug 14, 2020
Priority date	Jun 28, 2019
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A motor parameter tracking method, which can dynamically track motor parameters includes: exciting, with a voltage excitation signal, a motor to operate, and acquiring at least one actual voltage across two terminals of the motor and an actual current flowing through the motor in an operating state; modelling a voltage error of the motor based on the at least one actual voltage and the actual current to obtain a voltage error function of the motor; and performing iteration on at least one motor parameter based on the voltage error function and a preset iterative step. With the method, the difference between different batches of motors can be adaptively adjusted, and parameter changes caused by a motor temperature, a motor posture and the like can be dynamically tracked. All motor parameters are provided with a same step, which reduces the difficulty of parameter adjustment and the sensitivity of algorithms to parameters.

First claim

What is claimed is:

1. A motor parameter tracking method, comprising:
exciting, with a voltage excitation signal, a motor to operate, and acquiring at least one actual voltage across two terminals of the motor and an actual current flowing through the motor in an operating state;
modelling a voltage error of the motor based on the at least one actual voltage and the actual current to obtain a voltage error function of the motor; and
performing iteration on at least one motor parameter based on the voltage error function and a preset iterative step in such a manner that the at least one motor parameter is dynamically tracked;
said modelling the voltage error of the motor based on the at least one actual voltage and the actual current to obtain the voltage error function of the motor comprises:
obtaining the voltage error function based on a difference between one of the at least one actual voltage and a predicted voltage of each of different sampling points, wherein the predicted voltage is calculated based on the at least one motor parameter and a motor model.

2. The motor parameter tracking method as described in claim 1 , wherein the voltage excitation signal is a digital signal, and said exciting, with the voltage excitation signal, the motor to operate comprises:
converting, by a digital-to-analog converter, the digital signal into an analog signal;
amplifying, by a power amplifier, the analog signal; and
exciting, with the amplified analog signal, the motor to operate.

3. The motor parameter tracking method as described in claim 1 , wherein said obtaining the voltage error function based on the difference between the one of the at least one actual voltage and the predicted voltage of each of the different sampling points comprises:
calculating the voltage error function based on:
ε oev [ n ]= v cm [ n ]− v cp [ n ],

where n represents a sampling point index, v cm represents an actual voltage, and v cp represents the predicted voltage.

4. The motor parameter tracking method as described in claim 1 , wherein said calculating the predicted voltage based on the at least one motor parameter and the motor model comprises:
calculating the predicted voltage based on:

v

c
⁢
p

⁡

[
n
]

=

R

e
⁢
b

⁡

[
n
]

⁢

i

c
⁢
m

⁡

[
n
]

+

L

e
⁢
b

⁡

[
n
]

⁢

d
⁢

i

c
⁢
m

d
⁢
t

⁡

[
n
]

+

ϕ
0

⁡

[
n
]

⁢

u
d

⁡

[
n
]

,

where n represents a sampling point index, R eb represents a resistance of the motor, i cm represents the actual current, L eb represents an inductance of the motor, ϕ 0 represents an electromagnetic force coefficient, and u d represents a vibrator speed of the motor.

5. The motor parameter tracking method as described in claim 4 , wherein the vibrator speed of the motor is calculated based on:
u d [ n ]=σ u [ n ] f c·p [ n ]−σ n [ n ] f c·p [ n− 2]− a 1 [ n ] u d [ n− 1]− a 2 [ n ] u d [ n− 2],

where n represents the sampling point index, σ u , a 1 and a 2 represent coefficients of a second-order model of the motor, respectively, and f c·p is an electromagnetic force.

6. The motor parameter tracking method as described in claim 5 , wherein the electromagnetic force is calculated based on:
f c·p [ n ]=ϕ 0 [ n ] i c·m [ n ],

where n represents the sampling point index, ϕ 0 represents the electromagnetic force coefficient, and icm represents the actual current.

7. The motor parameter tracking method as described in claim 1 , wherein the preset iterative step is set for each of the at least one motor parameter, and said performing the iteration on the at least one motor parameter based on the voltage error function and the preset iterative step in such a manner that the at least one motor parameter is dynamically tracked comprises:
performing normalized least mean square adaptive filtering on the at least one motor parameter based on the voltage error function and the preset iterative step to obtain at least one tracking result of the at least one motor parameter.

8. The motor parameter tracking method as described in claim 7 , wherein the at least one motor parameter comprises a resistance, an inductance, a filter feedback coefficient and an electromagnetic force coefficient, and
a tracking result of the resistance is:

R
eb

⁡

[

Assignees

• Aac Technologies Pte Ltd

Inventors

• Li Tao
• Guo Xuan
• Xiang Zheng

Classifications

• H02P6/12

  Monitoring commutation; Providing indication of commutation failure · CPC title

• H02P25/032

  Reciprocating, oscillating or vibrating motors · CPC title

• H02P23/0022

  Model reference adaptation, e.g. MRAS or MRAC, useful for control or parameter estimation · CPC title

• H02P23/14 Primary

  Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage · CPC title

• H02P2205/01

  Current loop, i.e. comparison of the motor current with a current reference · CPC title