US4783728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modular power supply with PLL control
Assignee: Modular Power Corp
•
Filing: 1987-07-08
•
Granted: 1988-11-08
•
Expires: 2007-07-08
Abstract
Abstract An uninterruptible power supply includes removable individual power modules, which for example may be 10 kilowatts each and are removable from the overall system without adversely affecting the remaining modules. Each module by means of pulse width modulated switching converts the line AC to DC where it is stored by use of capacitors or a battery and then inverted from DC back to AC. This is done on a three-phase basis without need of any low frequency transformer connection. Common input and output control units provide for the basic pulse width modulated switching signals and other necessary signals. The efficiency and speed of the system is enhanced by the use of cascode switches, saturable cores in transformers and inductors, and a proportional base drive to the switching transistors.
Inventors
- 👤 David C. Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:44
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/493; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/062; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/453; H02M5/458; H02M5/4585; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04126; H03K17/042; H03K17/0422; H03K17/51; H03K17/56; H03K17/567
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
202 words
A power supply for converting single or multi-phase line AC in a regulated manner to a desired single or multi-phase output comprising: a plurality of substantially identical switched power modules connected in parallel to said AC line and to said output including input switching means switched by pulse width modulated signals for converting AC to DC and output switching means controlled by pulse width modulated signals for converting AC to DC and output switching means controlled by pulse width modulated signals for converting DC to AC; and input and output control means separate from said power modules for driving said switching means with said pulse width modulated signals whereby any one of said substantially identical switched power modules may be removed from said system without adversely affecting the remaining plurality of switched power modules, said output control means including digital phase locked loop means (PLL) for generating said pulse width modulated switching signal, said PLL including microprocessor means for comparing an output sinusoidal voltage generated by said PLL with an input sinusoidal voltage, and counter and memory means driven by said microprocessor means in accordance with said comparing, for producing said output sinusoidal voltage of a frequency determined by said microprocessor means.
Claim 2
Dependent Claim
202 words
A power supply for converting single or multi-phase line AC in a regulated manner to a desired single or multi-phase output comprising: a plurality of substantially identical switched power modules connected in parallel to said AC line and to said output including input switching means switched by pulse width modulated signals for converting AC to DC and output switching means controlled by pulse width modulated signals for converting AC to DC and output switching means controlled by pulse width modulated signals for converting DC to AC; and input and output control means separate from said power modules for driving said switching means with said pulse width modulated signals whereby any one of said substantially identical switched power modules may be removed from said system without adversely affecting the remaining plurality of switched power modules, said output control means including digital phase locked loop means (PLL) for generating said pulse width modulated switching signal, said PLL including microprocessor means for comparing an output sinusoidal voltage generated by said PLL with an input sinusoidal voltage, and counter and memory means driven by said microprocessor means in accordance with said comparing, for producing said output sinusoidal voltage of a frequency determined by said microprocessor means.
Claim 3
Dependent Claim
38 words
A power supply as in claim 1 in which the electrical connection is made between the AC input through the plurality of switched power modules directly to the output without the use of a low frequency transformer coupling.
Claim 4
Dependent Claim
46 words
A power supply as in claim 1 where said counter and memory means includes a read only memory containing amplitudes of sine wave at sequential addresses which are addressed by said counter means and a multiplying digital to analog converter means driven by said memory means.
Claim 5
Dependent Claim
31 words
A power supply as in claim 3 where said microprocessor means provides a reference output to said multiplying digital to analog converter to determine the amplitude of said output sinusoidal voltage.
Claim 6
Dependent Claim
46 words
A power supply as in claim 4, including pulse width modulation signal forming means, including a comparator means comparing said sinusoidal output voltage with the actual AC output voltage of said power supply, the output of said comparator driving said pulse width modulation signal forming means.
Claim 7
Dependent Claim
28 words
A power supply as in claim 1 including an energy storage means between said input and output switching means connected between said DC bus and a return line.
Claim 8
Dependent Claim
40 words
A power supply as in claim 1 where said microprocessor means is selectively responsive to a said input voltage which is at said line frequency or a nominal frequency and includes means for slewing between said line and nominal frequency.
Claim 9
Dependent Claim
32 words
A power supply as in claim 1 where said microprocessor means provides a frequency operating range where if said line frequency goes outside of said range a nominal frequency is locked onto.
Claim 10
Dependent Claim
30 words
A power supply as in claim 1 together with a snubber means included in said switching means, including an inductor with a saturated core to minimize energy storage during turn-on.
Claim 11
Dependent Claim
31 words
A power supply as in claim 1 where each of said switching means includes cascode connected switches responsive to a single pulse width modulated input signal for providing a switching action.
Claim 12
Dependent Claim
55 words
A power supply as in claim 10 where said cascode switches each include a bipolar transistor which is rated at a high voltage and has relatively slow switching speed with its emitter coupled to a field effect transistor rated at a relatively low voltage but with a fast switching speed and providing said single input.
Claim 13
Dependent Claim
28 words
A power supply as in claim 10 where said cascode switches include in their input means for controlling the level of turn-on base current for said bipolar transistor.
Claim 14
Dependent Claim
15 words
A power supply as in claim 10 where said cascode switches include antisaturation clamp means.
Claim 15
Dependent Claim
16 words
A power supply as in claim 10 where said cascode switches include proportional base drive means.
Claim 16
Dependent Claim
26 words
A power supply as in claim 14 where said proportional base drive means include transformer means for supplying a proportional base current to said bipolar transistor.
Claim 17
Dependent Claim
29 words
A power supply as in claim 15 including means for resetting said transformer means within 10% or less of the period of the frequency of operation of said transformer.
Claim 18
Dependent Claim
36 words
A power supply as in claim 16 where said resetting means includes a winding on said transformer and means for applying a reset pulse to said winding for cyclically inverting the magnetic field of said transformer.
References Cited (Backward Citations)
US3601682A
Cited
US3697852A
Cited
US3872364A
Cited
DE2516247A1
Cited
US4203151A
Cited
US4270163A
Cited
US4328454A
Cited
US4392099A
Cited
US4432032A
Cited
US4447695A
Cited
US4349772A
Cited
US4410935A
Cited
US4408270A
Cited
US4399395A
Cited
US4427933A
Cited
US4454574A
Cited
US4475150A
Cited
US4553197A
Cited
US4555754A
Cited
US4622628A
Cited
US4626978A
Cited
US4620296A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |