Patent US4833389A successfully refreshed from Google Patents.
US4833389A
Expired / Lapsed
US
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Current source inverter control system for load commutated induction motor drive
Assignee: Westinghouse Electric Corp
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Filing: 1988-09-26
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Granted: 1989-05-23
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Expires: 2008-09-26
Abstract
Abstract In a load commutated induction motor drive stability is achieved in a runaway situation by generating in response to the motor speed reference signal a signal representative of the desired power factor angle and in using such signal to delay by that much the gating pulses controlling the current-sourced inverter.
Inventors
- 👤 Leonard J. Kovalsky
- 👤 Alberto Abbondanti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:57
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/42; H02M1/4208; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/443; H02M5/45; H02M5/4505; H02M5/453; H02M5/458; H02M5/4585; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/024; Y; Y02; Y02B; Y02B70/00; Y02B70/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
162 words
In a Load Commutated Inverter Induction Motor (LCI/IM) drive including: an AC power supply, a converter for converting said power supply into DC current, an inverter coupled through input lines to the motor, a DC-link between said converter and said inverter, and a bank of capacitors in parallel with the motor; first means being provided for controlling said converter in relation to the voltage of said output lines and to a speed reference signal; and second means being provided responsive to said speed reference signal for generating and applying gating pulses to said inverter; the combination of: third means responsive to said speed reference signal for generating a signal representative of the power factor angle on said output lines; and fourth means responsive to said output lines for generating zero-crossing characteristic signals in accordance with the voltages on said output lines; said gating pulses being provided by said zero-crossing signals and being delayed in the amount of said power factor representative signal.
Claim 2
Dependent Claim
162 words
In a Load Commutated Inverter Induction Motor (LCI/IM) drive including: an AC power supply, a converter for converting said power supply into DC current, an inverter coupled through input lines to the motor, a DC-link between said converter and said inverter, and a bank of capacitors in parallel with the motor; first means being provided for controlling said converter in relation to the voltage of said output lines and to a speed reference signal; and second means being provided responsive to said speed reference signal for generating and applying gating pulses to said inverter; the combination of: third means responsive to said speed reference signal for generating a signal representative of the power factor angle on said output lines; and fourth means responsive to said output lines for generating zero-crossing characteristic signals in accordance with the voltages on said output lines; said gating pulses being provided by said zero-crossing signals and being delayed in the amount of said power factor representative signal.
Claim 3
Dependent Claim
68 words
The LCI/IM drive of claim 1 with said third means being a function generator calculating the function φ=F(f*), where φ is the power factor angle, f* is the speed reference signal, and F is a function given by the equation: φ=sin.sup.-1 {(Vm/Is)[ωC-(1/ωLm)]} Vm being the emf of the motor, ωLm the magnetizing reactance of the model of the motor drive, and C the parallel capacitance across the motor.
Claim 4
Dependent Claim
48 words
The LCI/IM drive of claim 1 with said third means being a lookup table means having stored therein the values of the power factor angle φ as a function of f* the frequency of the AC power supply, said lookup table being addressed by said speed reference signal.
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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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |