US4977492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suppression of switching harmonics
Assignee: Sundstrand Corp
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Filing: 1990-04-25
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Granted: 1990-12-11
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Expires: 2010-04-25
Abstract
Abstract An inverter controller adjusts a selected switching pattern to accommodate minor variations and loads in the neighborhood of that pattern. The controller realizes in real-time the equivalent of an iterative solution of predetermined patterns. A number of representative pulse width modulated (PWM) patterns are selected for a range of loads and link ripple. A portion of the fundamental output is inserted onto the d.c. link to control one or more higher harmonics.
Inventors
- 👤 Maurice A. Kirchberg, Jr.
- 👤 Alexander Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:43
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/539; H02M7/5395
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
122 words
A controller for an inverter of the type including a source of d.c. voltage, inverter switches controlled by the controller to chop said d.c. voltage to generate a pulse width modulated pattern, and a filter for smoothing the pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, comprising: means for adjusting individual ones of said switching angles to control harmonics through the Nth harmonic in the inverter output; means for inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
Claim 2
Dependent Claim
122 words
A controller for an inverter of the type including a source of d.c. voltage, inverter switches controlled by the controller to chop said d.c. voltage to generate a pulse width modulated pattern, and a filter for smoothing the pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, comprising: means for adjusting individual ones of said switching angles to control harmonics through the Nth harmonic in the inverter output; means for inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
Claim 3
Dependent Claim
22 words
The controller recited in claim 1 wherein said means for inserting inserts a portion of a fundamental signal from said sinusoidal output.
Claim 4
Dependent Claim
207 words
A controller for an inverter of the type including a source of d.c. voltage, inverter switches controlled by the controller to chop said d.c. voltage to generate a pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, comprising: means for computing an NxN' sensitivity matrix, where N is the number of controlled harmonics, and N' is the number of independent switching angles in a switching angle set, the elements of said matrix representing sensitive to change of controlled harmonics with respect to individual switching angles means for computing an unbalance vector, said unbalance vector being a function of the harmonic coefficients of the output of the inverter for the controlled harmonics; means for determining whether said unbalance vector is less than a predetermined threshold; means responsive to said sensitivity matrix and said unbalance vector for adjusting individual ones of said switching angles when said unbalance vector is greater than said predetermined threshold; and means for inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
Claim 5
Dependent Claim
207 words
A controller for an inverter of the type including a source of d.c. voltage, inverter switches controlled by the controller to chop said d.c. voltage to generate a pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, comprising: means for computing an NxN' sensitivity matrix, where N is the number of controlled harmonics, and N' is the number of independent switching angles in a switching angle set, the elements of said matrix representing sensitive to change of controlled harmonics with respect to individual switching angles means for computing an unbalance vector, said unbalance vector being a function of the harmonic coefficients of the output of the inverter for the controlled harmonics; means for determining whether said unbalance vector is less than a predetermined threshold; means responsive to said sensitivity matrix and said unbalance vector for adjusting individual ones of said switching angles when said unbalance vector is greater than said predetermined threshold; and means for inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
Claim 6
Independent Claim
127 words
A method for controlling an inverter of the type including a source of d.c. voltage, inverter switches controlled by a controller to chop said d.c. voltage to generate a pulse width modulated pattern, and a filter for smoothing the pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, said method comprising the controller performed steps of: adjusting individual ones of said switching angles to control harmonics through the Nth harmonic in the inverter output; and inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
Claim 7
Independent Claim
127 words
A method for controlling an inverter of the type including a source of d.c. voltage, inverter switches controlled by a controller to chop said d.c. voltage to generate a pulse width modulated pattern, and a filter for smoothing the pulse width modulated pattern to produce a generally sinusoidal output, said controller selecting from a plurality of stored switching angle sets an initial switching angle set for controlling said inverter switches based on sensed parameters at an output of said inverter, said method comprising the controller performed steps of: adjusting individual ones of said switching angles to control harmonics through the Nth harmonic in the inverter output; and inserting a signal on said source of d.c. voltage to control at least one harmonic higher than said Nth harmonic.
References Cited (Backward Citations)
US4357655A
Cited
US4382275A
Cited
US4527226A
Cited
US4519022A
Cited
US4635177A
Cited
US4595976A
Cited
US4800478A
Cited
US4757434A
Cited
US4763059A
Cited
US4935860A
Cited
US4935859A
Cited
US4937720A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
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