US4602198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction motor drive using load commutated inverter circuit
Assignee: General Electric Co
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Filing: 1985-02-26
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Granted: 1986-07-22
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Expires: 2005-02-26
Abstract
Abstract A system for controlling the operation of an alternating current induction motor having windings supplied by electrical power from the polyphase alternating current source includes a load commutated inverter circuit which is connected between the power source and the induction motor for furnishing electrical power to the motor. Controllers responsive to a command signal and a feedback signal indicative of motor operating parameters control the operation of said load commutated inverter circuit. There is further provided a fixed capacitor circuit connected between the windings of the motor for supplying reactive volt amperes (VARs) to said load commutated inverter circuit and said motor. Finally, there is provided a variable VAR generator connected between the motor windings for supplying VARs to said load commutated inverter circuit and said motor in response to the output of a third feedback control path which is also responsive to a command signal and prescribed operating parameter(s) of said load and/or said commutated inverter.
Inventors
- 👤 Herbert W. Weiss
- 👤 Loren H. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:55
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/18; H02J3/1892; H02M; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/443; H02M5/45; H02M5/4505; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/024; H02P27/00; H02P27/04; H02P27/06; H02P2201/00; H02P2201/13; H02P2207/00; H02P2207/01
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
208 words
A system for controlling the operation of an alternating current induction motor having windings supplied with electrical power from a polyphase alternating current power source comprising: (a) a load commutated inverter circuit connected between the power source and said induction motor for furnishing electrical power to said motor, said load commutated inverter circuit including a controllable alternating current to direct current converter and a controllable direct current to alternating current converter interconnected by a direct current connecting link; (b) a first feedback control path responsive to a command signal and a feedback signal indicative of a motor operating parameter to control the operation of said alternating current to direct current converter; (c) a second feedback control path responsive to a command signal to control the operation of said direct current to alternating current converter; (d) a capacitor circuit connected between said motor windings for supplying reactive volt-amperes to said load commutated inverter circuit and said motor; (e) a variable VAR generator connected between said motor windings for supplying reactive volt-amperes to said load commutated inverter circuit and said motor in response to a VAR command signal; and, (f) a third feedback control loop for generating said VAR command signal in response to prescribed operating parameters of said motor.
Claim 2
Independent Claim
208 words
A system for controlling the operation of an alternating current induction motor having windings supplied with electrical power from a polyphase alternating current power source comprising: (a) a load commutated inverter circuit connected between the power source and said induction motor for furnishing electrical power to said motor, said load commutated inverter circuit including a controllable alternating current to direct current converter and a controllable direct current to alternating current converter interconnected by a direct current connecting link; (b) a first feedback control path responsive to a command signal and a feedback signal indicative of a motor operating parameter to control the operation of said alternating current to direct current converter; (c) a second feedback control path responsive to a command signal to control the operation of said direct current to alternating current converter; (d) a capacitor circuit connected between said motor windings for supplying reactive volt-amperes to said load commutated inverter circuit and said motor; (e) a variable VAR generator connected between said motor windings for supplying reactive volt-amperes to said load commutated inverter circuit and said motor in response to a VAR command signal; and, (f) a third feedback control loop for generating said VAR command signal in response to prescribed operating parameters of said motor.
Claim 3
Dependent Claim
20 words
The invention in accordance with claim 1 wherein said variable VAR generator includes means to generate only leading reactive volt-amperes.
Claim 4
Dependent Claim
20 words
The invention in accordance with claim 1 wherein said variable VAR generator includes means to generate only lagging reactive volt-amperes.
Claim 5
Dependent Claim
21 words
The inventon in accordance with claim 1 wherein said VAR generator includes means to generate both leading and lagging reactive volt-amperes.
Claim 6
Dependent Claim
25 words
The invention in accordance with claim 1 wherein said polyphase alternating current source, said load commutated inverter circuit and said motor are each three phase.
Claim 7
Dependent Claim
29 words
The invention in accordance with claim 5 wherein said variable VAR generator includes a three phase, load commutated power converter terminated, on DC terminals thereof, in a reactance load.
Claim 8
Dependent Claim
55 words
The invention in accordance with claim 5 wherein said variable VAR generator includes a three phase capacitor circuit having three legs each of which includes a capacitor element in series circuit with controllable switching devices which are selectively rendered conductive to thereby place said generator in circuit with the output of said load commutated inverter.
Claim 9
Dependent Claim
27 words
The invention in accordance with claim 5 wherein said variable VAR generator comprises a forced commutated power converter terminated, on DC terminals thereof, in a reactive load.
Claim 10
Dependent Claim
19 words
The invention in accordance with claim 8 wherein forced commutated converter includes a three phase autosequentially commutated inverter circuit.
Claim 11
Dependent Claim
17 words
The invention in accordance with claim 8 wherein forced commutated converter includes a gate turnoff device inverter.
Claim 12
Dependent Claim
39 words
The invention in accordance with claim 8 wherein said forced commutated controller includes an inverter circuit including, associated with each phase, two power controlled rectifiers and a commutation circuit including a controlled switching device, a capacitor and an inductor.
Claim 13
Dependent Claim
34 words
The invention in accordance with claim 8 wherein said forced commutated inverter includes an inverter circuit comprising gate turnoff devices in each of three legs, said inverter circuit being terminated in a reactive load.
Claim 14
Independent Claim
146 words
A method of controlling the operation of an alternating current induction motor having windings supplied with electrical power from a polyphase alternating current source comprising the steps: (a) furnishing electrical power to said motor using a load commutated inverter circuit including a controllable alternating current to direct current converter and a controllable direct current to alternating current converter interconnected by a direct current connecting link; (b) developing a control signal representing a motor operating parameter; (c) separately controlling each of said converters as functions of said control signal; (d) providing reactive volt-amperes to said load commutated inverter circuit and said motor using a capacitor circuit connected to said inverter circuit and said motor; (e) providing additional reactive volt-amperes to said load commutated inverter circuit and said motor using a controllable VAR generator; and, (f) controlling said VAR generator in response to a prescribed motor operating parameter.
Claim 15
Independent Claim
146 words
A method of controlling the operation of an alternating current induction motor having windings supplied with electrical power from a polyphase alternating current source comprising the steps: (a) furnishing electrical power to said motor using a load commutated inverter circuit including a controllable alternating current to direct current converter and a controllable direct current to alternating current converter interconnected by a direct current connecting link; (b) developing a control signal representing a motor operating parameter; (c) separately controlling each of said converters as functions of said control signal; (d) providing reactive volt-amperes to said load commutated inverter circuit and said motor using a capacitor circuit connected to said inverter circuit and said motor; (e) providing additional reactive volt-amperes to said load commutated inverter circuit and said motor using a controllable VAR generator; and, (f) controlling said VAR generator in response to a prescribed motor operating parameter.
Claim 16
Dependent Claim
16 words
The method in accordance with claim 13 wherein said controllable VAR generator develops leading reactive volt-amperes.
Claim 17
Dependent Claim
16 words
The method in accordance with claim 13 wherein said controllable VAR generator develops lagging reactive volt-amperes.
Claim 18
Dependent Claim
22 words
The method in accordance with claim 13 wherein said controllable VAR generator is selectively controlled to supply leading and lagging reactive volt-amperes.
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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) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |