Method for detecting initial magnetic-pole position of rotor in permanent magnet synchronous motor

Patent metadata

Field	Value
Publication number	US-2016268936-A1
Application number	US-201615059675-A
Country	US
Kind code	A1
Filing date	Mar 3, 2016
Priority date	Mar 10, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

The method for detecting an initial position of a magnetic pole of a rotor included in a permanent magnet synchronous motor according to an embodiment of the present disclosure includes generating three-phase voltage vectors to be applied onto a u-phase, a v-phase, and a w-phase of a stator winding, applying the three-phase voltage vectors on the u-phase, the v-phase, and the w-phase of a stator winding, respectively, calculating a current difference value of the u-phase, a current difference value of the v-phase, and a current difference value of the w-phase using currents of the stator winding flowing in a magnetizing direction and in a un-magnetizing direction by applying the three-phase voltage vectors, and determining the initial position of the magnetic pole of the rotor using the current difference value of the u-phase, the current difference value of the v-phase, and the current difference value of the w-phase.

First claim

What is claimed is:

1 . A method for detecting an initial position of a magnetic pole of a rotor in a permanent magnet synchronous motor, the motor comprising a stator and the rotor, the method comprising:
generating three-phase voltage vectors to be applied onto a u-phase, a v-phase, and a w-phase of a stator winding; applying the three-phase voltage vectors onto the u-phase, the v-phase, and the w-phase of the stator winding, respectively; calculating a current difference value in the u-phase, a current difference value in the v-phase, and a current difference value in the w-phase using currents of the stator winding flowing in a magnetizing direction and in a un-magnetizing direction by applying the three-phase voltage vectors; and determining the initial position of the magnetic pole of the rotor using the current difference value in the u-phase, the current difference value in the v-phase, and the current difference value in the w-phase.

2 . The method according to claim 1 , wherein the initial position of the magnetic pole is determined by an angle made between a d-axis of the stator and a d-axis of a rotor winding.

3 . The method according to claim 1 , wherein generating three-phase voltage vectors comprises:
generating voltage commands including a d-axis voltage command and a q-axis voltage command of the stator winding; generating angle commands to be applied to the three-phase voltage vectors; generating synchronous coordinate system voltage vectors using the voltage commands and the angle commands; and transforming the synchronous coordinate system voltage vectors into a three-phase coordinate system voltage vector to generate the three-phase voltage vectors.

4 . The method according to claim 1 , wherein calculating the current difference value comprises:
deciding a difference between an absolute value of a current flowing in the magnetizing direction and an absolute value of a current flowing in the un-magnetizing direction as the current difference value.

5 . The method according to claim 1 , wherein the initial position of the magnetic pole is determined as follows:

θ
re

=

arctan
(

3



(

I
v

-

I
w

)

2


I
u

-

I
v

-

I
w

)

where θ re is an angle formed between a d-axis of the stator and a d-axis of a rotor winding, IU is the current difference value in the u-phase, IV is the current difference value in the v-phase, and IW is the current difference value in the w-phase.

Assignees

• Lsis Co Ltd

Inventors

• Chi Min-Hun

Classifications

• H02P6/183 Primary

  using an injected high frequency signal · CPC title

• H02P21/34 Primary

  Arrangements for starting · CPC title

• H02P2203/03

  Determination of the rotor position, e.g. initial rotor position, during standstill or low speed operation · CPC title

• H02P6/18 Primary

  without separate position detecting elements · CPC title

• H02P21/18

  Estimation of position or speed · CPC title