Method and system for controlling motor of environmentally-friendly vehicle

Patent metadata

Field	Value
Publication number	US-9306489-B2
Application number	US-201314138713-A
Country	US
Kind code	B2
Filing date	Dec 23, 2013
Priority date	Oct 10, 2013
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A method and system for controlling a vehicle motor are provided. The system includes an inverter that controls the motor to receive a torque command from an external system and output a torque based on the torque command. Additionally, a current command is generated based on the torque command and a operation condition of the motor. A voltage command is generated to be applied to the motor based on the current command and the operation condition of the motor. A pulse width modulation (PWM) command is generated based on the voltage command and the operation condition of the motor. The PWM command is converted to a voltage in a PWM form based on the motor operation condition and is applied to the motor. Then, an unwanted torque output of the motor generated based on a nonlinear characteristic of the motor is added and subtracted to and from the torque command.

First claim

What is claimed is:

1. A system for controlling a motor, comprising:
a controller configured to control the motor in the system,
wherein the controller is configured to:
control the motor to receive a torque command from an external system;
output a torque based on the torque command from the motor:
generate a current command based on the torque command received in the controller and an operation condition of the motor;
generate a voltage command to be applied to the motor based on the generated current command and the operation condition of the motor;
generate a pulse width modulation (PWM) command based on the generated voltage command and the operation condition of the motor;
convert the generated PWM command to a voltage in a PWM form based on the operation condition of the motor;
apply the converted voltage to the motor;
subtract an unwanted torque output of the motor generated based on a nonlinear characteristic of the motor from the torque command;
predict a position of a rotor of the motor at a second time based on a position of the rotor that is measured at a first time, the second time being after the time;
extract the unwanted torque output of the motor as unnecessary torque based on the predicted position of the rotor;
attenuate the extracted unwanted torque output to a predetermined value; and
output a modified torque command by subtracting the attenuated unwanted torque output from the torque command.

2. The system of claim 1 , wherein the controller is further configured to:
select current commands to obtain the torque output based on the torque command; and
select voltage commands to cause currents based on the selected current commands to flow in the motor,
wherein the torque output, the currents, and voltages based on the voltage commands satisfy the formulae below:

dFlux
=

(

Vqsr
-

Rs
·
Iqsr

)

·

1
Wr

qFlux
=

(

-
Vdsr

+

Rs
·
Idsr

)

·

1
Wr

Te
=

Iqsr
·
dFlux

-

Idsr
·
qFlux

wherein dFlux is a d-axis of flux linkage, qFlux is a q-axis of flux linkage, Idsr is a d-axis stator Reference current, Iqsr is a q-axis stator Reference current, Vdsr is a d-axis stator Reference voltage, Vqsr is a q-axis stator Reference voltage, Rs is a stator coil resistance of the motor, Te is the torque output, and Wr is an electrical angular velocity of a motor rotor.

3. The system of claim 2 , wherein the voltage applied to the motor is expressed by a formula selected from a group consisting of:

Vqsr
=

Rs
·
Iqsr

+

dFlux
·
Wr

=

∑

N
=
0

∞

⁢

[

Vqsr

(
N
)

s

·

sin
⁡

(

N
·
θ

⁢

⁢
r

)

+

Vqsr

(
N
)

c

·

cos
⁡

(

N
·
θ

⁢

⁢
r

)

]

Vqsr
=

∑

N
=
0

∞

⁢

[

Vqsr

(
N
)

s

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Yoo Taeil
• Park Han Hee

Classifications

• H02P21/05

  specially adapted for damping motor oscillations, e.g. for reducing hunting · CPC title

• H02P29/50 Primary

  Reduction of harmonics · CPC title

• H02P29/0038 Primary

  Electricity · mapped topic

• H02P21/14 Primary

  Estimation or adaptation of machine parameters, e.g. flux, current or voltage · CPC title

• B60L15/20

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title