US3665495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
No break power system
Assignee: Power Systems and Controls Inc
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Filing: 1970-06-01
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Granted: 1972-05-23
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Expires: 1990-06-01
Abstract
Abstract A standby power supply system is disclosed wherein a load is normally connected to and driven by the output of a synchronous generator. The generator is in turn driven by a synchronous motor energized by a three-phase oscillator controlled inverter which derives its power from a source of direct current. This direct current is provided by a rectified utility source during normal operation and by a standby power source when a fault occurs in the utility. The standby source is shown as a high capacity battery floating on the DC line, whereby it is charged by the utility, and is also immediately available for standby operation. The inverter oscillator is controlled to maintain phase and frequency synchronization between the load power and the utility during normal operation, but becomes free running during standby.
Inventors
- 👤 Robert Carter
- 👤 Ralph A Amos
- 👤 Charles A Gregory Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:33
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/066; Y; Y02; Y02B; Y02B70/00; Y02B70/30; Y04; Y04S; Y04S20/00; Y04S20/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
325 words
A no-break power supply system for providing power continuously to a critical load and for providing total electrical isolation of the load from the normal power source, comprising: a synchronous motor-synchronous generator set mechanically coupled for concurrent rotation, said synchronous motor having a leading power factor; a source of first alternating current; rectifier means connected to said source of first alternating current for converting said first alternating current to direct current; an inverter network having an input and an output and comprising a plurality of controlled rectifiers, each having a control electrode, the input of said inverter network being coupled to said rectifier means to receive said direct current; pulse generating means for applying pulses to said control electrodes to selectively turn on said controlled rectifiers and provide a second alternating current at the output of said inverter network; means connecting the output of said inverter network to said synchronous motor for supplying said second alternating current to said motor and for driving said motor continuously at a speed determined by the frequency of said second alternating current, the leading power factor of said synchronous motor serving to commutate said inverter network, said motor in turn driving said synchronous generator to produce a third alternating current; a standby source of direct current connected to and normally floating across the input to said inverter network for supplying power to said system during a fault condition; means responsive to said first and third alternating currents for controlling the frequency of said pulse generating means to bring said first and third alternating currents into phase synchronization; means responsive to a fault condition for disabling said means for controlling the frequency of said pulse generating means, whereby said pulse generating means becomes free running; and load means connected to said synchronous generator for continuously receiving only that current which is supplied by said synchronous generator whereby said load means is electrically isolated from said source of first alternating current.
Claim 2
Dependent Claim
325 words
A no-break power supply system for providing power continuously to a critical load and for providing total electrical isolation of the load from the normal power source, comprising: a synchronous motor-synchronous generator set mechanically coupled for concurrent rotation, said synchronous motor having a leading power factor; a source of first alternating current; rectifier means connected to said source of first alternating current for converting said first alternating current to direct current; an inverter network having an input and an output and comprising a plurality of controlled rectifiers, each having a control electrode, the input of said inverter network being coupled to said rectifier means to receive said direct current; pulse generating means for applying pulses to said control electrodes to selectively turn on said controlled rectifiers and provide a second alternating current at the output of said inverter network; means connecting the output of said inverter network to said synchronous motor for supplying said second alternating current to said motor and for driving said motor continuously at a speed determined by the frequency of said second alternating current, the leading power factor of said synchronous motor serving to commutate said inverter network, said motor in turn driving said synchronous generator to produce a third alternating current; a standby source of direct current connected to and normally floating across the input to said inverter network for supplying power to said system during a fault condition; means responsive to said first and third alternating currents for controlling the frequency of said pulse generating means to bring said first and third alternating currents into phase synchronization; means responsive to a fault condition for disabling said means for controlling the frequency of said pulse generating means, whereby said pulse generating means becomes free running; and load means connected to said synchronous generator for continuously receiving only that current which is supplied by said synchronous generator whereby said load means is electrically isolated from said source of first alternating current.
Claim 3
Dependent Claim
40 words
The no-break power supply system of claim 1, wherein said pulse generating means includes a voLtage controlled oscillator and wherein said means for controlling the frequency of said pulse generating means includes means for regulating the frequency of said oscillator.
Claim 4
Dependent Claim
107 words
The no-break power supply system of claim 2, wherein said means for regulating the frequency of said oscillator comprises sensing means for producing a first DC control signal proportional to the load current, means for producing a second DC control signal proportional to the phase angle difference between said pulse generating means and said first alternating current, and summing means for combining said first and second DC control signals, and wherein said means responsive to a fault condition includes a ground clamp for grounding the output of said summing means to disable said means for regulating the frequency of said oscillator, whereby said oscillator becomes free running.
Claim 5
Dependent Claim
55 words
The no-break power supply system of claim 3, wherein said source of first alternating current includes an auxiliary supply of alternating current, means for energizing said auxiliary supply upon the occurrence of a fault condition, and means for connecting said auxiliary supply to said system for supplying power thereto until said fault condition is corrected.
Claim 6
Dependent Claim
75 words
The no-break power supply system of claim 2, wherein said pulse generating means further includes a ring counter responsive to the output of said voltage controlled oscillator for producing a train of pulsed output signals for the control electrode of each of said inverter rectifiers, and firing means for each of said inverter rectifiers responsive to a corresponding train of pulsed output signals for sequentially turning on said rectifiers to provide said second alternating current.
Claim 7
Dependent Claim
38 words
The no-break power supply system of claim 5, wherein said means for regulating the frequency of said voltage-controlled oscillator comprises logic control means including phase comparison means for detecting phase differences between said first and second alternating currents.
Claim 8
Dependent Claim
79 words
The no-break power system of claim 6, wherein said phase comparison means comprises a frequency comparator for sensing and indicating whether said second alternating current is in phase or out of phase with said first alternating current, a phase discriminator for producing a phase control signal proportional to the difference in phase between said first and second alternating currents, and means for applying said phase control signal to said controlled oscillator for synchronizing said first and second alternating current.
Claim 9
Dependent Claim
52 words
The no-break power system of claim 7, further including clamp means for disabling said means for applying said phase control signal to said controlled oscillator when said frequency comparator senses that said first and second alternating currents are out of phase by a predetermined amount, whereupon said controlled oscillator becomes free running.
References Cited (Backward Citations)
US2783393A
Cited
US2972056A
Cited
US3142793A
Cited
US3229111A
Cited
US3243598A
Cited
US3296451A
Cited
US3345517A
Cited
US3418550A
Cited
US3526778A
Cited
US3614461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |