Patent US3893787A successfully refreshed from Google Patents.
US3573602A
Expired / Lapsed
US
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Three-phase inverter
Assignee: Danfoss AS
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Filing: 1969-06-16
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Granted: 1971-04-06
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Expires: 1989-06-16
Abstract
Abstract The invention relates to a three-phase inverter producing a stepped voltage between each two output terminals which approximates the sinusoidal form. The apparatus includes two three-phase inverter systems of the type comprising pairs of parallel arranged controllable rectifiers and three transformers each having a primary winding and two secondary windings.
Inventors
- 👤 Arne Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:26
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/483; H02M7/49; H02M7/02; H02M7/04; H02M7/06; H02M7/068
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
133 words
A three-phase inverter comprising two three-phase inverter systems, each of said systems having three parallel arranged pairs of controllable one-way valves with the valves of each pair being connected in series, three transformers each having a primary winding and a pair of secondary windings, each of said primary windings having each end thereof connected to opposite ones of said systems and between the valves of one of said pairs of valves, one of said secondary windings of each of said transformers being terminalized with a terminal connection on one side thereof, and a center tap for each of said primary windings being in series with one of said secondary windings of a first different phase which in turn is in series with one of said terminalized secondary windings of a second different phase.
Claim 2
Dependent Claim
133 words
A three-phase inverter comprising two three-phase inverter systems, each of said systems having three parallel arranged pairs of controllable one-way valves with the valves of each pair being connected in series, three transformers each having a primary winding and a pair of secondary windings, each of said primary windings having each end thereof connected to opposite ones of said systems and between the valves of one of said pairs of valves, one of said secondary windings of each of said transformers being terminalized with a terminal connection on one side thereof, and a center tap for each of said primary windings being in series with one of said secondary windings of a first different phase which in turn is in series with one of said terminalized secondary windings of a second different phase.
Claim 3
Dependent Claim
93 words
A three-phase inverter for producing stepped voltages approximating sinusoidal forms, comprising, three output terminals, first means for providing between each pair of said terminals a basic impulse which is shortened a predetermined amount relative to a half cycle and substantially occupies the amplitude-time area of a sinusoidal form, and second means for providing between each pair of said terminals two auxiliary impulses of like amplitude symmetrically disposed relative to said basic impulse, said impulses being summed and said amplitude of said auxiliary impulses being substantially smaller than the amplitude of said basic impulse.
Claim 4
Dependent Claim
93 words
A three-phase inverter for producing stepped voltages approximating sinusoidal forms, comprising, three output terminals, first means for providing between each pair of said terminals a basic impulse which is shortened a predetermined amount relative to a half cycle and substantially occupies the amplitude-time area of a sinusoidal form, and second means for providing between each pair of said terminals two auxiliary impulses of like amplitude symmetrically disposed relative to said basic impulse, said impulses being summed and said amplitude of said auxiliary impulses being substantially smaller than the amplitude of said basic impulse.
Claim 5
Dependent Claim
33 words
An inverter according to claim 2 wherein said second means includes transformer means, said auxiliary impulses being transmitted through said transformer means and said basic impulses being transmitted to said terminals without transformation.
Claim 6
Dependent Claim
45 words
An inverter according to claim 2 wherein said first means produces two wave trains each being 180* square waves, said wave train having a relative displacement equal to said predetermined amount, said wave trains being combined to form a mean value representing said basic impulse.
Claim 7
Dependent Claim
21 words
An inverter according to claim 4 including a choke having an intermediate tapping, said mean value being formed at said choke.
Claim 8
Dependent Claim
51 words
An inverter according to claim 2 wherein said basic impulse is symmetrical relative to a half cycle and said predetermined amount equals 30*, said auxiliary impulses being symmetrical relative to a half cycle and being separated from each other by 30*, each of said auxiliary impulses having a duration of 30*.
Claim 9
Dependent Claim
23 words
An inverter according to claim 2 wherein the amplitude of said auxiliary impulses is 15.5 percent of the amplitude of said basic impulse.
Claim 10
Dependent Claim
39 words
An inverter according to claim 3 wherein said first means produces two wave trains each being 180* square waves, said auxiliary impulses being produced by differentiation of said two wave trains in two neighboring phases of said transformer means.
Claim 11
Dependent Claim
25 words
An inverter according to claim 5 wherein said choke transmits the power of said auxiliary impulses and is a primary winding of said transformer means.
Claim 12
Dependent Claim
36 words
An inverter according to claim 9 wherein said tapping is connected to one of said terminals through two secondary windings connected in series, said secondary windings being in two different neighboring phases of said transformer means.
Claim 13
Dependent Claim
19 words
An inverter according to claim 10 wherein said two secondary windings are oppositely connected relative to said transformer means.
Claim 14
Dependent Claim
52 words
An inverter according to claim 5 including two DC input terminals, two pairs of controllable circuit elements connected in series with said DC terminals, said choke having the opposite ends thereof connected respectively between the elements of each said pair, said elements being controllable at like frequency with a 30* time displacement.
Claim 15
Dependent Claim
40 words
An inverter according to claim 3 wherein said transformer means has an iron core, with at least three limbs, said transformer means having three phases arranged respectively on said limbs, said transformer means having at least one additional unwound limb.
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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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |