US6933702B2
Expired / Lapsed
US
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Control method and system for motor
Assignee: National Kaohsiung University of Science and Technology
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Filing: 2003-10-14
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Granted: 2005-08-23
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Expires: 2023-10-14
Abstract
Abstract The invention relates to a control method and a control system for a motor. The control method and the control system of the invention transfer the motor dynamic equations of the synchronous d-q frame into a motor parameter (for example, the leakage inductance) and the equivalent counter electromotive force. Then the required control signals for the motor current control can be obtained. The control method of the invention not only preserves the merit of constant switching frequency of the convention PI-PWM control system, but also can eliminate the motor current phase-lag problem of the invention PI-PWM control system. Also, the control method of the invention will have the following characteristics and economic advantages such as high accuracy, fast response, low cost and robustness, etc.
Inventors
- 👤 Chin-Yuan Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:10
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/34; H02P21/22
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
169 words
A control method for a motor, comprising the steps of: (a) determining a motor parameter; (b) providing a d-axis reference current and a q-axis reference current; (c) detecting actual currents of the motor and converting them into a d-axis actual current and a q-axis actual current; (d) calculating a d-axis counter electromotive force and a q-axis counter electromotive force at a sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis actual current and the q-axis actual current at a last sample period, and a d-axis voltage and a q-axis voltage at the last sample period; and (e) calculating a d-axis voltage and a q-axis voltage at the sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis reference current and the q-axis reference current at a next sample period, the d-axis counter electromotive force and the q-axis counter electromotive force at the sample period.
Claim 2
Dependent Claim
169 words
A control method for a motor, comprising the steps of: (a) determining a motor parameter; (b) providing a d-axis reference current and a q-axis reference current; (c) detecting actual currents of the motor and converting them into a d-axis actual current and a q-axis actual current; (d) calculating a d-axis counter electromotive force and a q-axis counter electromotive force at a sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis actual current and the q-axis actual current at a last sample period, and a d-axis voltage and a q-axis voltage at the last sample period; and (e) calculating a d-axis voltage and a q-axis voltage at the sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis reference current and the q-axis reference current at a next sample period, the d-axis counter electromotive force and the q-axis counter electromotive force at the sample period.
Claim 3
Dependent Claim
33 words
The control method according to claim 1 , wherein in the step (d) the d-axis counter electromotive force and the q-axis counter electromotive force are equal to zero at a first ample period.
Claim 4
Dependent Claim
26 words
The control method according to claim 1 , further comprising a step (f) for converting the d-axis voltage and the q-axis voltage into three phase voltages.
Claim 5
Dependent Claim
36 words
The control method according to claim 3 , further comprising a step (g) for calculating three phase control voltages according to the three phase voltages, a peak value of a comparing voltage and a DC voltage.
Claim 6
Dependent Claim
44 words
The control method according to claim 4 , further comprising a step (h) for comparing the three phase control voltages and a comparing voltage of a PWM comparator to control a switch-mode inverter and to obtain three phase input voltage for controlling the motor.
Claim 7
Dependent Claim
35 words
The control method according to claim 5 , further a repeat step for repeating the step (c) to the step (h) to calculate the three phase input voltages during all period for controlling the motor.
Claim 8
Dependent Claim
20 words
The control method according to claim 1 , in the step (a) wherein the motor parameter is a leakage inductance.
Claim 9
Dependent Claim
15 words
The control method according to claim 7 , wherein the leakage inductance is a constant.
Claim 10
Dependent Claim
57 words
The control method according to claim 7 , wherein the leakage inductance is determined according to the d-axis voltage and the q-axis voltage at the last sample period and a last two sample period, the d-axis actual current and the q-axis actual current at the sample period, the last sample period and a last two sample period.
Claim 11
Dependent Claim
181 words
A control system for a motor comprising: an input means for receiving a motor parameter, a d-axis reference current and a q-axis reference current; a detecting means for detecting actual currents of the motor and converting the three phase currents to a d-axis actual current and a q-axis actual current; a first calculating means for calculating a d-axis counter electromotive force and a q-axis counter electromotive force at a sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis actual current and the q-axis actual current at a last sample period, and a d-axis voltage and a q-axis voltage at the last sample period; and a second calculating means for calculating a d-axis voltage and a q-axis voltage at the sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis reference current and the q-axis reference current at a next sample period, the d-axis counter electromotive force and the q-axis counter electromotive force at the sample period.
Claim 12
Dependent Claim
181 words
A control system for a motor comprising: an input means for receiving a motor parameter, a d-axis reference current and a q-axis reference current; a detecting means for detecting actual currents of the motor and converting the three phase currents to a d-axis actual current and a q-axis actual current; a first calculating means for calculating a d-axis counter electromotive force and a q-axis counter electromotive force at a sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis actual current and the q-axis actual current at a last sample period, and a d-axis voltage and a q-axis voltage at the last sample period; and a second calculating means for calculating a d-axis voltage and a q-axis voltage at the sample period according to the motor parameter, the d-axis actual current and the q-axis actual current at the sample period, the d-axis reference current and the q-axis reference current at a next sample period, the d-axis counter electromotive force and the q-axis counter electromotive force at the sample period.
Claim 13
Dependent Claim
26 words
The control system according to claim 10 , further comprising a converting means for converting the d-axis voltage and the q-axis voltage into three phase voltages.
Claim 14
Dependent Claim
37 words
The control system according to claim 11 , further comprising a third calculating means for calculating three phase control voltages according to the three phase voltages, a peak value of a comparing voltage and a DC voltage.
Claim 15
Dependent Claim
24 words
The control system according to claim 12 , further comprising a PWM comparator for comparing the three phase control voltages and a comparing voltage.
Claim 16
Dependent Claim
32 words
The control system according to claim 13 , further comprising a switch-mode inverter for outputting three phase input voltage to the motor according to three phase switching signals from the PWM comparator.
Claim 17
Dependent Claim
16 words
The control method according to claim 10 , wherein the motor parameter is a leakage inductance.
Claim 18
Dependent Claim
62 words
The control system according to claim 15 , further comprising a fourth calculating means for calculating the leakage inductance according to the d-axis voltage and the q-axis voltage at the last sample period and a last two sample period, the d-axis actual current and the q-axis actual current at the sample period, the last sample period and a last two sample period.
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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) | 2008-08-22 | 2009-02-21 | 2009-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-08-22 | 2013-02-21 | 2013-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-08-22 | 2017-02-21 | 2017-08-23 | $7700.00 | Window Closed / Lapsed |