US4585985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of real time operating point identification and pole adjustment for an induction motor drive system
Assignee: General Electric Co
•
Filing: 1984-08-09
•
Granted: 1986-04-29
•
Expires: 2004-08-09
Abstract
Abstract A microcomputer based method for adjusting feedback loop gains ensures a fast, predetermined response of an induction motor drive system. A pre-computed look-up table contains gain values to be loaded into feedback regulators, the gain values corresponding to each operating point of the induction motor having the values necessary to keep the poles of the closed loop system substantially constant.
Inventors
- 👤 Bimal K. Bose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:55
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
A method of obtaining a fast, predetermined transient response in an induction motor drive system having a control using state variable feedback through a variable regulator gain matrix, said method comprising the steps of: determining when the induction motor of said drive system is operating in steady state; determining selected steady state values defining an operating point; looking up regulator gain values in a look-up table addressed by said selected steady state values, said look-up table containing regulator gain values at each distinct operating point to fix the locations of the drive system poles to achieve the desired transient response at each operating point; and loading said gain values in the corresponding regulators.
Claim 2
Independent Claim
113 words
A method of obtaining a fast, predetermined transient response in an induction motor drive system having a control using state variable feedback through a variable regulator gain matrix, said method comprising the steps of: determining when the induction motor of said drive system is operating in steady state; determining selected steady state values defining an operating point; looking up regulator gain values in a look-up table addressed by said selected steady state values, said look-up table containing regulator gain values at each distinct operating point to fix the locations of the drive system poles to achieve the desired transient response at each operating point; and loading said gain values in the corresponding regulators.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said control is a torque-slip control and wherein said selected steady state values are stator voltage, inverter frequency and motor speed.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein said control is a field-oriented control and wherein said selected steady state values are stator voltage, inverter frequency and motor speed.
Claim 5
Dependent Claim
31 words
The method of claim 1 wherein said look-up table further includes the poles of the open loop induction motor drive system at each operating point defined by said steady state values.
Claim 6
Dependent Claim
172 words
An induction motor drive system comprising: an induction motor; an inverter coupled to said motor and adapted to be coupled to a source of DC power for supplying variable frequency and amplitude AC power to said induction motor in response to a frequency command and an amplitude command; an estimator coupled to said inverter and to said motor for calculating the torque, flux and stator current of said motor; a tachometer coupled to said motor for measuring actual rotor speed; feedback means coupled to said estimator, said tachometer and said inverter for employing state variable feedback to generate said frequency and amplitude commands in response to said calculated torque, flux and stator current and in response to an operator commanded flux and an operator commanded rotor speed, said feedback means including a variable regulator gain matrix; and a microcomputer coupled to said feedback means and to said tachometer for controlling the gains of said variable regulator gain matrix to achieve a predetermined response at each steady state operating point of said motor.
Claim 7
Dependent Claim
172 words
An induction motor drive system comprising: an induction motor; an inverter coupled to said motor and adapted to be coupled to a source of DC power for supplying variable frequency and amplitude AC power to said induction motor in response to a frequency command and an amplitude command; an estimator coupled to said inverter and to said motor for calculating the torque, flux and stator current of said motor; a tachometer coupled to said motor for measuring actual rotor speed; feedback means coupled to said estimator, said tachometer and said inverter for employing state variable feedback to generate said frequency and amplitude commands in response to said calculated torque, flux and stator current and in response to an operator commanded flux and an operator commanded rotor speed, said feedback means including a variable regulator gain matrix; and a microcomputer coupled to said feedback means and to said tachometer for controlling the gains of said variable regulator gain matrix to achieve a predetermined response at each steady state operating point of said motor.
References Cited (Backward Citations)
US4258302A
Cited
US4442393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |