Apparatus for determining start of electric machine

Patent metadata

Field	Value
Publication number	US-9660562-B2
Application number	US-201414309676-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Jul 2, 2013
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An apparatus for determining start of electric machine is disclosed wherein a frequency of a 3-phase current inputted from a motor is estimated to determine whether the motor has started using a difference between the estimated frequency and a frequency of output voltage of inverter configured to drive the motor.

First claim

What is claimed is:

1. An apparatus for determining start of an electric machine, the apparatus comprising:
a current converter configured to output a first AC (Alternating Current) signal corresponding to a frequency component of at least one phase current input to a 3-phase motor from an inverter and to output a second AC signal having a phase angle that lags a phase angle of the first AC signal by 90°;
an estimator configured to estimate a frequency of the second AC signal;
a bandwidth decision unit configured to determine a control bandwidth of the estimated frequency estimated by the estimator; and
a determiner configured to determine whether the 3-phase motor has started according to a difference between the estimated frequency and a frequency of an output voltage of the inverter,
wherein the control bandwidth is determined according to a gain of the estimator, and
wherein the gain of the estimator is selected as a value higher than an operation frequency of the 3-phase motor.

2. The apparatus of claim 1 , wherein the estimator receives a positive inoperable input frequency of the motor and outputs the received frequency when start of the motor is not determined in order to determine whether the motor has successfully started.

3. The apparatus of claim 1 , wherein the determiner determines that the motor has not started when the difference between the estimated frequency and the frequency of the output voltage of the inverter exceeds a preset frequency range.

Assignees

• Lsis Co Ltd

Inventors

• Yoo Anno

Classifications

• H02P6/18

  without separate position detecting elements · CPC title

• H02P21/18

  Estimation of position or speed · CPC title

• H02P1/265 Primary

  Means for starting or running a triphase motor on a single phase supply · CPC title

• H02P1/26 Primary

  for starting an individual polyphase induction motor · CPC title

• H02P6/20 Primary

  Arrangements for starting (H02P6/08 takes precedence) · CPC title