US 8,159,161 B2Granted

Motor control device

AssigneeSanyo Electric Co., Ltd.

InventorYoshio Tomigashi

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Abstract

To estimate an initial magnetic pole position, estimated control axes corresponding to the d-axis and q-axis are set as the γ-axis and δ-axis, and a with high frequency rotation voltage or alternating voltage on the γδ coordinate system applied to the motor. A high frequency current ih flowing in the motor is then extracted from a detected motor current (armature current) and a direct current component (ihγ×ihδ)DC of a product of the γ-axis and δ-axis components of the high frequency current ih is derived. Alternatively, the γ′-axis component ichγ and the δ′-axis component 66 of the high frequency current ih that are shifted by π/4 in electric angle from the γ-axis and the δ-axis are used to obtain a direct current component of their product (ichγ×ichδ)DC. The magnetic pole position is then estimated by computing the axial error Δθ between the γ-d axes utilizing the direct current components.

Claims11

Dependent claims

A motor control device for controlling a motor based on an estimated magnetic pole position, comprising:

a voltage applying unit for applying a voltage for estimation having a predetermined frequency to a motor;
a current detection unit for detecting a current that flows in the motor;
and
a magnetic pole position estimation unit for estimating a magnetic pole position in a rotor of the motor based on a current detected by the current detection unit;
wherein the magnetic pole position estimation unit includes an estimation processing unit for deriving a first axis component, a second axis component, a third axis component, and a fourth axis component of a current for estimation that flows in the motor due to application of the voltage for estimation from a first axis component and a second axis component of the current detected by the current detection unit, and estimating the magnetic pole position based on the first to the fourth axis components of the current for estimation, and
wherein in an electric angle expression, the first axis and the second axis are mutually orthogonal and the third axis and the fourth axis are mutually orthogonal, and each of the third axis and the fourth axis differs from the first axis.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/543,802Filed 19 Aug 2009
Priority: JP 2008-21189320 Aug 2008
Published: US 2010/0045218 A125 Feb 2010
Granted: 17 Apr 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H02P 6/185
Without separate position detecting elements: using inductance sensing, e.g. pulse excitation
H02P 6/183
Without separate position detecting elements: using an injected high frequency signal
H02P 21/18
Estimation or adaptation of machine parameters, e.g. flux, current or voltage: estimation of position or speed
H02P 21/32
Vector control not involving the use of rotor position or rotor speed sensors: determining the initial rotor position