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US6628099B2
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Synchronous motor driving system and sensorless control method for a synchronous motor
Assignee: Hitachi Ltd
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Filing: 2002-08-06
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Granted: 2003-09-30
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Expires: 2022-08-06
Abstract
Abstract Axial error calculation unit is provided for estimating an axial error Deltatheta between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.
Inventors
- 👤 Yoshitaka Iwaji
- 👤 Tsunehiro Endo
- 👤 Kiyoshi Sakamoto
- 👤 Yuhachi Takakura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:50
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/24; H02P6/00; H02P6/20; H02P6/21; H02P6/34
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
122 words
A method for controlling a synchronous motor driving system, the system including a synchronous motor, an inverter for driving the synchronous motor, a rotational speed command generator for supplying a rotational speed command to the synchronous motor, and a control unit for calculating a voltage applied to the synchronous motor, the method comprising: calculating an axial error, the axial error being a deviation between a magnetic pole axis of the synchronous motor and an assumed magnetic pole axis on control, by using a driving current command of the synchronous motor, a current value of the synchronous motor, an inductance constant of the synchronous motor and a generated power constant; and controlling the synchronous motor so that the calculated axial error approaches zero.
Claim 2
Independent Claim
122 words
A method for controlling a synchronous motor driving system, the system including a synchronous motor, an inverter for driving the synchronous motor, a rotational speed command generator for supplying a rotational speed command to the synchronous motor, and a control unit for calculating a voltage applied to the synchronous motor, the method comprising: calculating an axial error, the axial error being a deviation between a magnetic pole axis of the synchronous motor and an assumed magnetic pole axis on control, by using a driving current command of the synchronous motor, a current value of the synchronous motor, an inductance constant of the synchronous motor and a generated power constant; and controlling the synchronous motor so that the calculated axial error approaches zero.
Claim 3
Dependent Claim
15 words
The method of claim 1 , wherein the synchronous motor is of a salient type.
Claim 4
Dependent Claim
15 words
The method of claim 1 , wherein the synchronous motor is of a non-salient type.
Claim 5
Dependent Claim
72 words
The method of claim 1 , wherein the driving current command of the synchronous motor includes a current command on the magnetic pole axis and a current command on an axis orthogonal to the magnetic pole axis, and wherein the current value of the synchronous motor includes a detected current value on the assumed axis on control and a detected current value on an axis orthogonal to the assumed axis on control.
Claim 6
Dependent Claim
38 words
The method of claim 1 , wherein the current value of the synchronous motor is estimated based on a DC current on a power source side of the inverter and a driving pulse signal for driving the inverter.
Claim 7
Dependent Claim
49 words
The method of claim 1 , wherein the current value of the synchronous motor is a current value calculated based on a detected DC current value on a power source side of the inverter and a detected value or a set value of a DC voltage of the inverter.
Claim 8
Dependent Claim
152 words
A method of controlling a synchronous motor driving system according to claim 1 , said axial error Δθ being calculated using the equation: Δ θ = tan - 1 L q ( I qc - I q * ) K e - ( L q I d c - L d I d * ) wherein L d is an inductance of magnetic pole axis d, L q is an inductance of an axis q orthogonal to the magnetic pole axis d, K e is the generated power constant of the motor, I d * is a current command on the axis d, I q * is a current command on the axis q, I dc is a detected current value on an assumed axis dc, I qc is a detected current value on an assumed axis qc orthogonal to the assumed axis dc.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-09-29 | 2007-03-31 | 2007-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-09-29 | 2011-03-31 | 2011-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-09-29 | 2015-03-31 | 2015-09-30 | $7700.00 | Window Closed / Lapsed |