US5280421A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current regulator for a four-legged three-phase inverter
Assignee: General Electric Co
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Filing: 1992-06-17
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Granted: 1994-01-18
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Expires: 2012-06-17
Abstract
Abstract A current regulator for a four-legged, three-phase inverter determines the next optimal, or near-optimal, inverter state in a relatively short time period based on phase current error signals and back-emf's, resulting in low harmonic distortion, reduced current ripple, minimal current stresses, and increased utilization of the available dc bus voltage over a high bandwidth.
Inventors
- 👤 Rik W. A. A. De Doncker
- 👤 Paul M. Szczesny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:28
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5387; H02M7/53871; H02M7/53875; H02M7/4826
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
344 words
A current regulator for a four-legged, three-phase inverter, comprising: means for generating a current error signal for each respective phase leg of said inverter; means for measuring the back-emf of each respective phase leg of said inverter; current comparator means for comparing each respective current error signal with a current command; voltage comparator means for comparing each respective back-emf with a switching band voltage; switching state selection means for selecting the next switching state of each respective phase leg of said inverter, said switching state selection means selecting a positive switching state for a respective phase leg if the corresponding current error signal is less than or equal to said current command and the corresponding back-emf is greater than said switching band voltage, said switching state selection means selecting a negative switching state if the corresponding current error signal is greater than or equal to said current command and the corresponding back-emf is less than said switching band voltage, said switching state selection means otherwise selecting a freewheeling state; conflict resolution means for ensuring that the switching states for each phase leg have the same polarity, said conflict resolution means resolving conflicts between phase legs for which said switching state selection means has selected switching states of opposite polarity as follows: said conflict resolution means comparing the current error signal of each respective phase leg with a current error reference such that if any of the current error signals of the conflicting phases is greater than the current error reference, the switching state selected by said switching state selection means for the phase having the largest current error is allowed, a freewheeling state being selected for each of the other conflicting phases; said conflict resolution means comparing the back-emf's of the conflicting phases if the current error signal for each of the conflicting phases is less than the current error reference, such that the switching state selected by said switching state selection means for the phase having the largest back-emf is allowed, a freewheeling state being selected for each of the other conflicting phases.
Claim 2
Dependent Claim
344 words
A current regulator for a four-legged, three-phase inverter, comprising: means for generating a current error signal for each respective phase leg of said inverter; means for measuring the back-emf of each respective phase leg of said inverter; current comparator means for comparing each respective current error signal with a current command; voltage comparator means for comparing each respective back-emf with a switching band voltage; switching state selection means for selecting the next switching state of each respective phase leg of said inverter, said switching state selection means selecting a positive switching state for a respective phase leg if the corresponding current error signal is less than or equal to said current command and the corresponding back-emf is greater than said switching band voltage, said switching state selection means selecting a negative switching state if the corresponding current error signal is greater than or equal to said current command and the corresponding back-emf is less than said switching band voltage, said switching state selection means otherwise selecting a freewheeling state; conflict resolution means for ensuring that the switching states for each phase leg have the same polarity, said conflict resolution means resolving conflicts between phase legs for which said switching state selection means has selected switching states of opposite polarity as follows: said conflict resolution means comparing the current error signal of each respective phase leg with a current error reference such that if any of the current error signals of the conflicting phases is greater than the current error reference, the switching state selected by said switching state selection means for the phase having the largest current error is allowed, a freewheeling state being selected for each of the other conflicting phases; said conflict resolution means comparing the back-emf's of the conflicting phases if the current error signal for each of the conflicting phases is less than the current error reference, such that the switching state selected by said switching state selection means for the phase having the largest back-emf is allowed, a freewheeling state being selected for each of the other conflicting phases.
Claim 3
Independent Claim
300 words
A method for regulating current in a four-legged, three-phase inverter, comprising: (a) generating a current error signal for each respective phase leg of said inverter; (b) measuring the back-emf of each respective phase leg of said inverter; (c) comparing each respective current error signal with a current command; (d) comparing each respective back-emf with a switching band voltage; (e) selecting the next switching state of each respective phase leg of said inverter as follows: (1) selecting a positive switching state for a respective phase leg if the corresponding current error signal is less than or equal to said current command and the corresponding back-emf is greater than said switching band voltage; (2) selecting a negative switching state if the corresponding current error signal is greater than or equal to said current command and the corresponding back-emf is less than said switching band voltage; (3) otherwise selecting a freewheeling state; (f) ensuring that the switching states for each phase leg have the same polarity by resolving conflicts between phase legs for which said selecting step (e) has resulted in switching states of opposite polarity as follows: (1) comparing the current error signal of each respective phase leg with a current error reference such that if any of the current error signals of the conflicting phases is greater than the current error reference, the switching state selected in said selecting step is allowed, a freewheeling state being selected for each of the other conflicting phases; (2) comparing the back-emf's of the conflicting phases if the current error signal for each of the conflicting phases is less than the current error reference, such that the switching state selected in said selecting step for the phase having the largest back-emf is allowed, a freewheeling state being selected for each of the other conflicting phases.
Claim 4
Independent Claim
300 words
A method for regulating current in a four-legged, three-phase inverter, comprising: (a) generating a current error signal for each respective phase leg of said inverter; (b) measuring the back-emf of each respective phase leg of said inverter; (c) comparing each respective current error signal with a current command; (d) comparing each respective back-emf with a switching band voltage; (e) selecting the next switching state of each respective phase leg of said inverter as follows: (1) selecting a positive switching state for a respective phase leg if the corresponding current error signal is less than or equal to said current command and the corresponding back-emf is greater than said switching band voltage; (2) selecting a negative switching state if the corresponding current error signal is greater than or equal to said current command and the corresponding back-emf is less than said switching band voltage; (3) otherwise selecting a freewheeling state; (f) ensuring that the switching states for each phase leg have the same polarity by resolving conflicts between phase legs for which said selecting step (e) has resulted in switching states of opposite polarity as follows: (1) comparing the current error signal of each respective phase leg with a current error reference such that if any of the current error signals of the conflicting phases is greater than the current error reference, the switching state selected in said selecting step is allowed, a freewheeling state being selected for each of the other conflicting phases; (2) comparing the back-emf's of the conflicting phases if the current error signal for each of the conflicting phases is less than the current error reference, such that the switching state selected in said selecting step for the phase having the largest back-emf is allowed, a freewheeling state being selected for each of the other conflicting phases.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |