US3838330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement and method for converting electrical power without external supply of reactive power requirements
Assignee: AEG Westinghouse Industrial Automation Corp
•
Filing: 1973-04-13
•
Granted: 1974-09-24
•
Expires: 1993-04-13
Abstract
Abstract In a system utlizing a naturally commutated converter to convert AC power to DC power (or to convert DC power to AC power), a force commutated converter is placed in parallel with the naturally commutated converter. The input power factor of the force commutated converter is set to compensate for the reactive power required by the naturally commutated converter. The input power factor of the force commutated converter is equal but of opposite sign with respect to the input power factor to the naturally commutated converter, which has an inherently lagging input power factor.
Inventors
- 👤 J Rosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:47
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/66; H02M7/68; H02M7/72; H02M7/75; H02M7/757
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
203 words
An arrangement for converting electrical power without the necessity for externally supplying reactive power comprising: a naturally commutated converter circuit to convert an input signal to a desired output signal, one of said input and output signals being a direct current signal and the other being an alternating current signal, said naturally commutated converter circuit drawing an alternating current having an inherently lagging phase angle representative of a reactive power component; a force commutated converter circuit to convert an input signal to a desired output signal, one of said input and output signals being a direct current signal and the other being an alternating current signal, the input signal of said naturally commutated converter circuit corresponding to the input signal of said force commutated converter circuit, and the output signal of said naturally commutated converter circuit corresponding to the output signal of said force commutated converter circuit; and control means for force commutating said force commutated circuit, at appropriate times, to cause said force commutated converter circuit to draw an alternating current having a phase angle and amplitude such that when it is combined with the current drawn by said naturally commutated converter circuit there is no need to supply external reactive power.
Claim 2
Dependent Claim
203 words
An arrangement for converting electrical power without the necessity for externally supplying reactive power comprising: a naturally commutated converter circuit to convert an input signal to a desired output signal, one of said input and output signals being a direct current signal and the other being an alternating current signal, said naturally commutated converter circuit drawing an alternating current having an inherently lagging phase angle representative of a reactive power component; a force commutated converter circuit to convert an input signal to a desired output signal, one of said input and output signals being a direct current signal and the other being an alternating current signal, the input signal of said naturally commutated converter circuit corresponding to the input signal of said force commutated converter circuit, and the output signal of said naturally commutated converter circuit corresponding to the output signal of said force commutated converter circuit; and control means for force commutating said force commutated circuit, at appropriate times, to cause said force commutated converter circuit to draw an alternating current having a phase angle and amplitude such that when it is combined with the current drawn by said naturally commutated converter circuit there is no need to supply external reactive power.
Claim 3
Dependent Claim
73 words
An arrangement as claimed in claim 1 wherein: said input signals of said converter circuits are alternating current signals; said output signals of said converter circuits are direct current signals; and said control means causes said force commutated converter circuit to draw a current having an amplitude and a leading phase angle of the same magnitude as the amplitude and lagging phase angle of the current drawn by said naturally commutated converter circuit.
Claim 4
Dependent Claim
73 words
An arrangement as claimed in claim 1 wherein: said input signals of said converter circuits are direct current signals; said output signals of said converter circuits are alternating current signals; and said control means causes said force commutated converter circuit to draw a current having an amplitude and a leading phase angle of the same magnitude as the amplitude and lagging phase angle of the current drawn by said naturally commutated converter circuit.
Claim 5
Dependent Claim
160 words
An arrangement for converting electrical power without the necessity for externally supplying reactive power comprising: a naturally commutated converter circuit having an alternating current terminal and a direct current terminal the current at its alternating current terminal having an inherent lagging phase angle; a force commutated converter circuit having an alternating current terminal and a direct current terminal, said alternating current terminals of sAid naturally commutated and force commutated converter circuits having a common reference and being connected together, and said direct current terminals of said naturally commutated and force commutated converter circuits having a common reference and being connected together; and control means to force commutate said force commutated converter circuit to produce a current at its alternating current terminal that has a phase angle and amplitude such that, when the currents at said alternating current terminals of said naturally commutated and force commutated converter circuits are combined, the resultant current satisfies the reactive power requirements of the arrangement.
Claim 6
Dependent Claim
160 words
An arrangement for converting electrical power without the necessity for externally supplying reactive power comprising: a naturally commutated converter circuit having an alternating current terminal and a direct current terminal the current at its alternating current terminal having an inherent lagging phase angle; a force commutated converter circuit having an alternating current terminal and a direct current terminal, said alternating current terminals of sAid naturally commutated and force commutated converter circuits having a common reference and being connected together, and said direct current terminals of said naturally commutated and force commutated converter circuits having a common reference and being connected together; and control means to force commutate said force commutated converter circuit to produce a current at its alternating current terminal that has a phase angle and amplitude such that, when the currents at said alternating current terminals of said naturally commutated and force commutated converter circuits are combined, the resultant current satisfies the reactive power requirements of the arrangement.
Claim 7
Dependent Claim
35 words
An arrangement as claimed in claim 4 wherein both said naturally commutated converter circuit and said force commutated circuit have a plurality of alternating current terminals corresponding to a plurality of phase displaced electrical voltages.
Claim 8
Dependent Claim
191 words
An arrangement as claimed in claim 5 wherein: said naturally commutated converter circuit comprises a plurality of bistable switching devices related in number to the number of phase displaced electrical voltages and connected between a pair of direct current lines, one of said direct current lines being connected to said direct current terminal of said naturally commutated converter circuit; said force commutated converter circuit comprises a plurality of bistable switching devices related in number to the number of phase displaced electrical voltages and connected between a pair of direct current lines, one of said direct current lines being connected to said direct current terminal of said force commutated converter circuit; and a plurality of alternating current lines corresponding to the number of phase displaced electrical voltages are connected to said alternating current terminals of said converter circuits, each of said alternating current lines being connected to a predetermined side of a bistable switching device in said naturally commutated converter circuit and the same side of a bistable switching device in said force commutated converter circuit, each of said bistable switching devices having only one of said alternating current lines connected thereto.
Claim 9
Dependent Claim
180 words
An arrangement as claimed in claim 6 wherein said control means comprises: a first pair of bistable switching devices connected in series between said direct current lines of said naturally commutated converter circuit and oriented to convey current in a predetermined direction with respect to said direct current terminal thereof; a second pair of bistable switching devices connected in series between said direct current lines of said force commutated converter circuit and oriented to convey current in a predetermined direction with respect to said direct current terminal thereof, said first pair of bistable switching devices conveying current in a different direction with respect to said direct current terminal of said naturally commutated converter circuit than the direction said second pair of bistable switching devices conveys current with respect to said direct current terminal of said force commutated converter circuit; a capacitor connected between the midpoints of said first and second pairs of bistable switching devices; and firing means to actuate selected ones of the bistable switching devices in said first and second pairs of bistable switching devices at appropriate times.
Claim 10
Dependent Claim
28 words
An arrangement as claimed in claim 7 and further comprising reactors interconnecting said direct current terminals of said naturally commutated converter circuit and said force commutated converter circuit.
Claim 11
Dependent Claim
39 words
An arrangement as claimed in claim 7 wherein: the bistable switches in said first and second pairs of stable switches comprise silicon controlled rectifiers; and said firing means is connected to the gate terminals of said silicon controlled rectifiers.
Claim 12
Dependent Claim
188 words
An arrangement as claimed in claim 5 wherein: said naTurally commutated converter circuit comprises three pairs of bistable switching devices, each of said pairs of bistable switching devices connected in series between a pair of direct current lines, one of said direct current lines being connected to said direct current terminal of said naturally commutated converter circuit; said force commutated converter circuit comprises three pairs of bistable switching devices, each of said pairs of bistable switching devices connected in series between a pair of direct current lines, one of said direct current lines being connected to said direct current terminal of said force commutated converter circuit; and three alternating current lines are connected to said alternating current terminals of said converter circuits, each of said alternating current lines being connected to the midpoint of one of said pairs of bistable switching devices in said naturally commutated converter circuit and to the midpoint of one of said pairs of bistable switching devices in said force commutated converter circuit, each of said pairs of bistable switching devices having only one of said alternating current lines connected to the midpoint thereof.
Claim 13
Dependent Claim
179 words
An arrangement as claimed in claim 10 wherein said control means comprises: a first pair of bistable switching devices connected in series between said direct current lines of said naturally commutated converter circuit and oriented to convey current in a predetermined direction with respect to said direct current terminal thereof; a second pair of bistable switching devices connected in series between said direct current lines of said force commutated converter circuit and oriented to convey current in a predetermined direction with respect to said direct terminal thereof, said first pair of bistable switching devices conveying current in a different direction with respect to said direct current terminal of said naturally commutated converter circuit than the direction said second pair of bistable switching devices conveys current with respect to said direct current terminal of said force commutated converter circuit; a capacitor connected between the midpoints of said first and second pairs of bistable switching devices; and firing means to actuate selected ones of the bistable switching devices in said first and second pairs of bistable switching devices at appropriate times.
Claim 14
Dependent Claim
16 words
An arrangement as claimed in claim 11 wherein all of the bistable switching devices comprise thyristors.
Claim 15
Dependent Claim
29 words
An arrangement as claimed in claim 12 wherein: said thyristors comprise silicon controlled rectifiers; and said firing means is connected to the gate terminals of said silicon controlled rectifiers.
Claim 16
Dependent Claim
34 words
An arrangement as claimed in claim 13 and further comprising interphase reactors interconnecting said direct current terminals of said converter circuits to eliminate the ripple resulting from transitory voltage differences between said converter circuits.
Claim 17
Independent Claim
126 words
A method of converting electrical power without the necessity of externally supplying power requirements comprising: converting the applied signal by means of a naturally commutated converter circuit to give a desired output signal that supplies half of the real power requirements of the load, the naturally commutated converter circuit drawing a current having a lagging phase angle; converting the applied signal by means of a force commutated converter circuit to give a desired output signal that supplies half of the real power requirements of the load; and controlling the force commutated converter circuit to draw a current having a phase angle and magnitude such as to negate the need to provide external reactive power when combined with the alternating current of the naturally commutated converter circuit.
Claim 18
Independent Claim
126 words
A method of converting electrical power without the necessity of externally supplying power requirements comprising: converting the applied signal by means of a naturally commutated converter circuit to give a desired output signal that supplies half of the real power requirements of the load, the naturally commutated converter circuit drawing a current having a lagging phase angle; converting the applied signal by means of a force commutated converter circuit to give a desired output signal that supplies half of the real power requirements of the load; and controlling the force commutated converter circuit to draw a current having a phase angle and magnitude such as to negate the need to provide external reactive power when combined with the alternating current of the naturally commutated converter circuit.
References Cited (Backward Citations)
US3308368A
Cited
US3538412A
Cited
US3668507A
Cited
US3716775A
Cited
US3707665A
Cited
US3707668A
Cited
US3750004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |