Patent US3792286A successfully refreshed from Google Patents.
US3792286A
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Combining inverters for harmonic reduction
Assignee: Reliance Electric Co
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Filing: 1971-10-12
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Granted: 1974-02-12
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Expires: 1991-10-12
Abstract
Abstract A plurality of polyphase inverters are connected in circuit to substantially common polyphase loads through a polyphase reactor. Windings from each phase of each inverter are provided on the reactor to cancel the component of flux of the fundamental frequency within the reactor and to have the reactor substantially absorb the NP + OR - 1 harmonics where N is the number of inverters and P is the number of phases. For two threephase inverters this substantially cancels the fifth and seventh harmonic voltages within the reactor applying a true 12-step voltage wave to each of the two common three-phase loads with nothing smaller than the 11th harmonic voltage supplied to each load. The two inverters are phase displaced by 360*/2NP which normally at a 30* phase angle would be a voltage loss of 3 1/2 percent applied to the load yet this reactor connection applies 100 percent voltage to the loads and the load power factor is reflected directly to each inverter. The loads may be DC isolated, permitting series connection of the inputs of the inverters from a single high voltage DC supply.
Inventors
- 👤 U Meier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:27
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/483; H02M7/49
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
112 words
An inverter circuit for supplying energy to a plurality of loads, comprising in combination, a plurality of polyphase inverters operable at a minimum phase displacement therebetween of 360*/2NP where N is the number of inverters and P is the number of phases of each inverter, reactor means having a core with P legs, winding means on said reactor means for each phase of each inverter, and means connecting said winding means in series circuit with each inverter phase and its respective load of a plurality of loads to establish ampere-turns which vectorially cancel the fundamental frequency component of the flux within said reactor means and pass the fundamental frequency to the loads.
Claim 2
Dependent Claim
112 words
An inverter circuit for supplying energy to a plurality of loads, comprising in combination, a plurality of polyphase inverters operable at a minimum phase displacement therebetween of 360*/2NP where N is the number of inverters and P is the number of phases of each inverter, reactor means having a core with P legs, winding means on said reactor means for each phase of each inverter, and means connecting said winding means in series circuit with each inverter phase and its respective load of a plurality of loads to establish ampere-turns which vectorially cancel the fundamental frequency component of the flux within said reactor means and pass the fundamental frequency to the loads.
Claim 3
Dependent Claim
25 words
An inverter circuit as set forth in claim 1, wherein said connecting means connects said winding means between each inverter phase and its respective load.
Claim 4
Dependent Claim
25 words
An inverter circuit as set forth in claim 1, wherein said connecting means connects a load between each inverter phase and its respective reactor phase.
Claim 5
Dependent Claim
37 words
An inverter circuit as set forth in claim 1, wherein said winding means includes the same number of turns on each phase to provide cancellation of the fundamental frequency component of flux when the loads are equal.
Claim 6
Dependent Claim
23 words
An inverter circuit as set forth in claim 1, wherein the loads are polyphase loads equal in number to the number of inverters.
Claim 7
Dependent Claim
26 words
An inverter circuit as set forth in claim 1, wherein the loads are polyphase having the same number of phases as the phases of said inverters.
Claim 8
Dependent Claim
29 words
An inverter circuit as set forth in claim 1, wherein said winding means includes a plurality of windings connected in series between each inverter phase and its respective load.
Claim 9
Dependent Claim
43 words
An inverter circuit as set forth in claim 1, wherein said connecting means establishes a fundamental frequency voltage on said loads equal to 100 percent of the fundamental frequency output voltage of each inverter despite phase displacement of the outputs of said inverters.
Claim 10
Dependent Claim
23 words
An inverter circuit as set forth in claim 1, wherein said connecting means establishes the load power factor directly reflected to each inverter.
Claim 11
Dependent Claim
28 words
An inverter circuit as set forth in claim 1, wherein said connecting means establishes the currents in said plurality of inverters with a phase displacement therebetween of 360*/2NP.
Claim 12
Dependent Claim
48 words
An inverter circuit as set forth in claim 1, wherein said Connecting means connects a plurality of winding means on each phase of said reactor means to establish vector addition of the fundamental ampere turns on each phase to equal zero when the plurality of loads are equal.
Claim 13
Dependent Claim
21 words
An inverter circuit as set forth in claim 1, wherein said reactor means has a volt-ampere capacity only for harmonic voltages.
Claim 14
Dependent Claim
48 words
An inverter circuit as set forth in claim 1, wherein said connecting means connects said winding means to absorb within the reactor the NKP + or - 1 harmonics present in said plurality of inverters to eliminate said harmonics from the load, where K is any odd integer.
Claim 15
Dependent Claim
23 words
An inverter circuit as set forth in claim 1, wherein said connecting means establishes said inverters as DC isolated in the load connections.
Claim 16
Dependent Claim
29 words
An inverter circuit as set forth in claim 14, including connecting the DC inputs of said plurality of inverters in series on a single pair of DC supply terminals.
Claim 17
Dependent Claim
18 words
An inverter circuit as set forth in claim 1, wherein said reactor means includes a single polyphase reactor.
Claim 18
Dependent Claim
25 words
An inverter circuit as set forth in claim 16, including winding means on each phase of said reactor corresponding to a phase of said inverters.
Claim 19
Dependent Claim
22 words
An inverter circuit as set forth in claim 17, including two windings in said winding means on each phase of said reactor.
Claim 20
Dependent Claim
22 words
An inverter circuit as set forth in claim 17, including a major and a minor winding on each phase of said reactor.
Claim 21
Dependent Claim
57 words
An inverter circuit as set forth in claim 19, including four windings on each phase of said reactor including two major and two minor windings, a major and a minor winding being energized from different phases of one of the inverters and another major and minor winding being energized from different phases of another of said inverters.
Claim 22
Dependent Claim
19 words
An inverter circuit as set forth in claim 20, including a single rotor acted on by the plural loads.
Claim 23
Dependent Claim
42 words
An inverter circuit as set forth in claim 1, wherein said winding means consists of only one winding on each phase of said reactor means for one inverter and two windings on each phase of said reactor means for the other inverter.
Claim 24
Dependent Claim
139 words
An inverter circuit for supplying energy to a plurality of loads, comprising in combination, a plurality of polyphase inverters operable at a minimum phase displacement therebetween of 360*/2NP where N is the number of inverters and P is the number of phases of each inverter, reactor means having a core with P legs, winding means on said reactor means for each phase of each inverter, means connecting said winding means in series circuit with each inverter phase and its respective load of a plurality of loads to establish ampere-turns which vectorially cancel the fundamental frequency component of the flux within said reactor means and pass the fundamental frequency to the loads, and said connecting means establishing a voltage from said inverters applied to the combination of said reactor means and loads which has an absence of P harmonic voltage.
Claim 25
Dependent Claim
139 words
An inverter circuit for supplying energy to a plurality of loads, comprising in combination, a plurality of polyphase inverters operable at a minimum phase displacement therebetween of 360*/2NP where N is the number of inverters and P is the number of phases of each inverter, reactor means having a core with P legs, winding means on said reactor means for each phase of each inverter, means connecting said winding means in series circuit with each inverter phase and its respective load of a plurality of loads to establish ampere-turns which vectorially cancel the fundamental frequency component of the flux within said reactor means and pass the fundamental frequency to the loads, and said connecting means establishing a voltage from said inverters applied to the combination of said reactor means and loads which has an absence of P harmonic voltage.
Claim 26
Dependent Claim
25 words
An inverter circuit as set forth in claim 23, wherein said connecting means connects a load between each inverter phase and its respective reactor phase.
Claim 27
Dependent Claim
29 words
An inverter circuit as set forth in claim 23, wherein said winding means includes a plurality of windings connected in series between each inverter phase and its respective load.
Claim 28
Dependent Claim
43 words
An inverter circuit as set forth in claim 23, wherein said connecting means establishes a fundamental frequency voltage on said loads equal to 100 percent of the fundamental frequency output voltage of each inverter despite phase displacement of the outputs of said inverters.
Claim 29
Dependent Claim
25 words
An inverter circuit as set forth in claim 23, wherein said connecting means causes the load power factor to be directly reflected to each inverter.
Claim 30
Dependent Claim
28 words
An inverter circuit as set forth in claim 23, wherein said connecting means establishes the currents in said plurality of inverters with a phase displAcement therebetween of 360*/2NP.
Claim 31
Dependent Claim
48 words
An inverter circuit as set forth in claim 23, wherein said connecting means connects a plurality of winding means on each phase of said reactor means to establish vector addition of the fundamental ampere turns on each phase to equal zero when the plurality of loads are equal.
Claim 32
Dependent Claim
21 words
An inverter circuit as set forth in claim 23, wherein said reactor means has a volt-ampere capacity only for harmonic voltages.
Claim 33
Dependent Claim
44 words
An inverter circuit as set forth in claim 23, wherein said connecting means connects said winding means to substantially absorb within the reactor the NP + or - 1 harmonics present in said plurality of inverters to substantially eliminate said harmonics from the load.
Claim 34
Dependent Claim
48 words
An inverter circuit as set forth in claim 23, wherein said connecting means connects said winding means to absorb within the reactor the NKP + or - 1 harmonics present in said plurality of inverters to eliminate said harmonics from the load where K is any odd integer.
Claim 35
Dependent Claim
29 words
An inverter circuit as set forth in claim 23, including connecting the DC inputs of said plurality of inverters in series on a single pair of DC supply terminals.
Claim 36
Dependent Claim
18 words
An inverter circuit as set forth in claim 23, wherein said reactor means includes a single polyphase reactor.
Claim 37
Dependent Claim
22 words
An inverter circuit as set forth in claim 34, including a major and a minor winding on each phase of said reactor.
Claim 38
Dependent Claim
57 words
An inverter circuit as set forth in claim 35, including four windings on each phase of said reactor including two major and two minor windings, a major and a minor winding being energized from different phases of one of the inverters and another major and minor winding being energized from different phases of another of said inverters.
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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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |