Method for controlling medium-voltage inverter and system comprising the same

Patent metadata

Field	Value
Publication number	US-10425016-B2
Application number	US-201815866021-A
Country	US
Kind code	B2
Filing date	Jan 9, 2018
Priority date	Apr 27, 2017
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Disclosed herein are a method for controlling a medium-voltage inverter, and a system including the same. The system includes a motor, a medium-voltage inverter driving the motor, a control unit configured to control an output voltage from the medium-voltage inverter, and an output voltage measuring unit configured to measure counter electromotive force data of the motor including a voltage and a frequency of the counter electromotive force, and transmitting it to the control unit. The control unit generates the output voltage based on the measured counter electromotive force data to re-drive the motor when the output voltage measuring unit completes the measurement of the counter electromotive force data.

First claim

What is claimed is:

1. A system for controlling a medium-voltage inverter, wherein the system comprises:
a motor;
a medium-voltage inverter driving the motor;
a control unit configured to control an output voltage from the medium-voltage inverter; and
an output voltage measuring unit configured to measure counter electromotive force data of the motor comprising a voltage and a frequency of the counter electromotive force, and transmitting the counter electromotive force data to the control unit,
wherein the control unit generates the output voltage based on the measured counter electromotive force data to re-drive the motor when the output voltage measuring unit completes the measurement of the counter electromotive force data,
wherein when the output voltage measuring unit completes the measurement of the counter electromotive force data, the control unit generates the output voltage based on the measured counter electromotive force data to re-drive the motor, and
wherein the output voltage has a magnitude and a frequency equal to the voltage and the frequency, respectively, and is generated in the same phase as the counter electromotive force.

2. The system of claim 1 , wherein the output voltage measuring unit measures the counter electromotive force data from the counter electromotive force of the motor generated in the motor.

3. The system of claim 1 , wherein the output frequency is maintained while the magnitude of the output voltage increases until it reaches a predetermined ratio of an output voltage to an output frequency.

4. A method for controlling a medium-voltage inverter performed in a system comprising a motor and a medium-voltage inverter driving the motor, the method comprising:
measuring, by an output voltage measuring unit electrically connected to the motor, counter electromotive force data of the motor comprising a voltage and a frequency of the counter electromotive force;
re-driving, by the medium-voltage inverter, the motor based on the measured counter electromotive force data when the measurement of the counter electromotive force data is completed; and
increasing the magnitude of the output voltage from the medium-voltage inverter,
wherein in the measuring the counter electromotive force of the motor, the output voltage has a magnitude and a frequency equal to the voltage and the frequency, respectively, and is generated in the same phase as the counter electromotive force.

5. The method of claim 4 , wherein the measuring the counter electromotive force of the motor comprises
measuring, by the output voltage measuring unit, the counter electromotive force data from the counter electromotive force of the motor generated in the motor.

6. The method of claim 4 , wherein the increasing the magnitude of the output voltage of the medium-voltage inverter comprises increasing the magnitude of the output voltage until it reaches a predetermined ratio of an output voltage to an output frequency.

7. The method of claim 4 , wherein the increasing the magnitude of the output voltage of the medium-voltage inverter comprises increasing the magnitude of the output voltage only while maintaining the output frequency of the medium-voltage inverter.

8. The method of claim 4 , wherein the increasing the magnitude of the output voltage of the medium-voltage inverter comprises completing increasing the magnitude of the output voltage when it reaches a predetermined ratio of an output voltage to an output frequency.

Assignees

• Lsis Co Ltd

Inventors

• Kim Kyoung-Sue

Classifications

• H02P21/24

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

• H02P1/04 Primary

  Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter · CPC title

• H02P21/34

  Arrangements for starting · CPC title

• H02P23/07

  Polyphase or monophase asynchronous induction motors · CPC title

• H02P2207/01

  Asynchronous machines · CPC title