US5498945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peak-torque-per-ampere (PTPA) control method for an induction motor
Assignee: Siemens VDO Electric Drives Inc
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Filing: 1994-04-08
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Granted: 1996-03-12
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Expires: 2014-04-08
Abstract
Abstract In a field-oriented control method and apparatus for an induction motor, a desired quadrature-axis current i q * and a desired direct-axis current i d * are chosen. The desired quadrature-axis current i q * and desired direct-axis current i d * are related such that peak torque is produced by the motor per ampere of electric current flowing in the motor. The peak-torque-per-ampere condition implies that the motor is operating at high efficiency. Also, in a field oriented control method and apparatus for an induction motor, a desired quadrature-axis current i q * and a desired rotor flux λ r * are chosen. The desired quadrature-axis current i q * and desired rotor flux λ r * are related such that peak torque is produced by the motor per ampere of electric current flowing in the motor.
Inventors
- 👤 Rajiva Prakash
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:46
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/06; H02P21/08; H02P21/22
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
100 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired direct-axis current i d * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU26## where L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 2
Independent Claim
100 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired direct-axis current i d * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU26## where L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 3
Dependent Claim
26 words
A method for field-oriented control of an induction motor as recited in claim 1 further comprising the step of providing a look-up table embodying said relationship.
Claim 4
Independent Claim
86 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired direct-axis current i d * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU27## where L m is said magnetizing inductance of said induction motor.
Claim 5
Independent Claim
86 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired direct-axis current i d * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU27## where L m is said magnetizing inductance of said induction motor.
Claim 6
Dependent Claim
26 words
A method for field-oriented control of an induction motor as recited in claim 3 further comprising the step of providing a look-up table embodying said relationship.
Claim 7
Independent Claim
117 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired rotor flux l r * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired rotor flux l r * are related by the following relationships: ##EQU28## and λ.sub.r *=L.sub.m i.sub.d *, where i d * is a desired direct-axis current of said induction motor, L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 8
Independent Claim
117 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired rotor flux l r * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor; wherein said desired quadrature-axis current i q * and said desired rotor flux l r * are related by the following relationships: ##EQU28## and λ.sub.r *=L.sub.m i.sub.d *, where i d * is a desired direct-axis current of said induction motor, L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 9
Dependent Claim
26 words
A method for field-oriented control of an induction motor as recited in claim 5 further comprising the step of providing a look-up table embodying said relationships.
Claim 10
Independent Claim
104 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired rotor flux l r * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor wherein said desired quadrature-axis current i q * and said desired rotor flux l r * are related by the following relationships: ##EQU29## and λ.sub.r *=L.sub.m i.sub.d *, where L m is said magnetizing inductance of said induction motor and i d * is a desired direct-axis current of said induction motor.
Claim 11
Independent Claim
104 words
A method for field-oriented control of an induction motor, said method comprising the steps of: choosing a desired quadrature-axis current i q *; and choosing a desired rotor flux l r * as a function of said desired quadrature-axis current i q * and of a magnetizing inductance of said induction motor wherein said desired quadrature-axis current i q * and said desired rotor flux l r * are related by the following relationships: ##EQU29## and λ.sub.r *=L.sub.m i.sub.d *, where L m is said magnetizing inductance of said induction motor and i d * is a desired direct-axis current of said induction motor.
Claim 12
Dependent Claim
26 words
A method for field-oriented control of an induction motor as recited in claim 7 further comprising the step of providing a look-up table embodying said relationships.
Claim 13
Dependent Claim
107 words
A field-oriented control apparatus for an induction motor, said apparatus comprising: means for choosing a desired quadrature-axis current i q *; and means for choosing a desired direct-axis current i d *; wherein said desired direct-axis current i d * is a function of said desired quadrature-axis current i q * and a magnetizing inductance of said motor; and wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU30## where L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 14
Dependent Claim
107 words
A field-oriented control apparatus for an induction motor, said apparatus comprising: means for choosing a desired quadrature-axis current i q *; and means for choosing a desired direct-axis current i d *; wherein said desired direct-axis current i d * is a function of said desired quadrature-axis current i q * and a magnetizing inductance of said motor; and wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU30## where L m is said magnetizing inductance of said induction motor and L lr is a leakage inductance of the rotor of said induction motor.
Claim 15
Dependent Claim
31 words
A field-oriented control apparatus for an induction motor as recited in claim 9, wherein said means for choosing a direct-axis current i d * comprises a look-up table embodying said relationship.
Claim 16
Dependent Claim
31 words
A field-oriented control apparatus for an induction motor as recited in claim 9, wherein said means for choosing a quadrature-axis current i q * comprises a look-up table embodying said relationship.
Claim 17
Dependent Claim
93 words
A field-oriented control apparatus for an induction motor, said apparatus comprising: means for choosing a desired quadrature-axis current i q *; and means for choosing a desired direct-axis current i d *; wherein said desired direct-axis current i d * is a function of said desired quadrature-axis current i q * and a magnetizing inductance of said motor; and wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU31## where L m is said magnetizing inductance of said induction motor.
Claim 18
Dependent Claim
93 words
A field-oriented control apparatus for an induction motor, said apparatus comprising: means for choosing a desired quadrature-axis current i q *; and means for choosing a desired direct-axis current i d *; wherein said desired direct-axis current i d * is a function of said desired quadrature-axis current i q * and a magnetizing inductance of said motor; and wherein said desired quadrature-axis current i q * and said desired direct-axis current i d * are related by the following relationship: ##EQU31## where L m is said magnetizing inductance of said induction motor.
Claim 19
Dependent Claim
32 words
A field-oriented control apparatus for an induction motor as recited in claim 12, wherein said means for choosing a desired direct-axis current i d * comprises a look-up table embodying said relationship.
Claim 20
Dependent Claim
32 words
A field-oriented control apparatus for an induction motor as recited in claim 12, wherein said means for choosing a desired quadrature-axis current i q * comprises a look-up table embodying said relationship.
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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) | 1999-03-12 | 1999-09-11 | 2000-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-12 | 2003-09-11 | 2004-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-12 | 2007-09-11 | 2008-03-12 | $7700.00 | Window Closed / Lapsed |