US5889659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for estimating a load to optimize a backup energy system response
Assignee: Superconductivity Inc
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Filing: 1997-05-05
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Granted: 1999-03-30
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Expires: 2017-05-05
Abstract
Abstract A method of delivering an optimized power level from a backup energy system to a load connected to a primary energy supply via a DC link and an inverter is provided. The method has the steps of: sensing a voltage of the DC link connected to the load; connecting a converter between the backup energy supply and the DC link; evaluating a rate of change of the voltage of the DC link; determining an estimate of the average load current using the rate of change of the DC link voltage; and controlling the converter using the average load current to switch the optimized power output from the backup energy supply to the load. In an embodiment, the step of determining an estimate of the average load current using the rate of change of the DC link voltage is performed in accordance with a formula I load =C DC link (dV DC link /dt). Also, the step of evaluating a rate of change of the DC link voltage is performed by representing a plurality of DC link voltage samples taken over time as points in an x-y coordinate system connected by a best fit line such that the slope of the line represents the rate of change of the voltage of the DC link. Further, the step of evaluating the rate of change of the DC link voltage may be implemented using a first plurality of serially connected sample and hold amplifiers having a second plurality of difference amplifiers selectively connected to the first plurality of sample and hold amplifiers and an operational amplifier summer connected to sum outputs of the difference amplifiers to produce an output. The output is used to control the converter for an optimized power level output switchover.
Inventors
- 👤 Jeffery E. Emmerich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:15
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; G; G01; G01R; G01R19/00; G01R19/0092; H02J9/062; H02M; H02M1/00; H02M1/0067; H02M1/007
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
113 words
A method of delivering an optimized power level output from a backup energy system to a load connected to a primary energy supply via a DC link and an inverter, the method comprising the steps of: sensing a voltage of the DC link connected to the load; connecting a converter between the backup energy supply and the DC link; evaluating a rate of change of the voltage of the DC link; determining an estimate of the average load current using the rate of change of the DC link voltage; and controlling the converter using the average load current to deliver an optimized power level output from the backup energy supply to the load.
Claim 2
Independent Claim
113 words
A method of delivering an optimized power level output from a backup energy system to a load connected to a primary energy supply via a DC link and an inverter, the method comprising the steps of: sensing a voltage of the DC link connected to the load; connecting a converter between the backup energy supply and the DC link; evaluating a rate of change of the voltage of the DC link; determining an estimate of the average load current using the rate of change of the DC link voltage; and controlling the converter using the average load current to deliver an optimized power level output from the backup energy supply to the load.
Claim 3
Dependent Claim
43 words
The method of claim 1 further comprising the step of: setting an initial condition to control the converter so that when the converter switches on to deliver energy to the load, the initial condition sets pulse widths of switching elements in the converter.
Claim 4
Dependent Claim
28 words
The method of claim 1 further comprising the step of: allowing the voltage of the DC link to f all to a predetermined level before controlling the converter.
Claim 5
Dependent Claim
43 words
The method of claim 1 wherein the step of determining an estimate of the average load current using the rate of change of the DC link voltage is performed in accordance with a formula I load =C DC link (dV Dc link /dt).
Claim 6
Dependent Claim
70 words
The method of claim 1 wherein the step of evaluating a rate of change of the DC link voltage is performed by representing a plurality of DC link voltage samples taken over time as points in an x-y coordinate system and employing a curve-fitting algorithm to generate a best fit line such that the slope of the line represents the rate of change of the voltage of the DC link.
Claim 7
Dependent Claim
70 words
The method of claim 5 further comprising the step of: implementing the step of evaluating the rate of change of the DC link voltage using a first plurality of serially connected sample and hold amplifiers having a second plurality of difference amplifiers selectively connected to the first plurality of sample and hold amplifiers and an operational amplifier summer connected to sum outputs of the difference amplifiers to produce an output.
Claim 8
Dependent Claim
19 words
The method of claim 6 wherein the output of the operational amplifier summer is an estimate of the load.
Claim 9
Dependent Claim
21 words
The method of claim 6 wherein the output of the operational amplifier summer is an initial condition for controlling the converter.
Claim 10
Dependent Claim
36 words
The method of claim 1 further comprising the steps of: providing closed loop voltage control for the converter; using the estimate of the average load current as a feedback signal for the closed loop voltage control.
Claim 11
Dependent Claim
13 words
The method of claim 1 wherein the DC link comprises a capacitor bank.
Claim 12
Independent Claim
57 words
A method of estimating an electrical load on an inverter system having a DC link, the method comprising the steps of: sensing a voltage of the DC link; evaluating a rate of change of the DC link voltage; and calculating an estimate of an average load current, using the rate of change of the DC link voltage.
Claim 13
Independent Claim
57 words
A method of estimating an electrical load on an inverter system having a DC link, the method comprising the steps of: sensing a voltage of the DC link; evaluating a rate of change of the DC link voltage; and calculating an estimate of an average load current, using the rate of change of the DC link voltage.
Claim 14
Dependent Claim
13 words
The method of claim 11 wherein the DC link comprises a capacitor bank.
Claim 15
Dependent Claim
18 words
The method of claim 11 further comprising the step of providing a converter connected to the inverter system.
Claim 16
Dependent Claim
43 words
The method of claim 11 wherein the step of calculating an estimate of the average load current using the rate of change of the DC link voltage is performed in accordance with a formula I load =C DC link (dV DC link /dt).
Claim 17
Independent Claim
61 words
A method of estimating an electrical load on an inverter system having a DC link and a converter system, the method comprising the steps of: sensing a voltage of the DC link; evaluating a rate of change of the DC link voltage; and calculating an estimate of an average load current, using the rate of change of the DC link voltage.
Claim 18
Independent Claim
61 words
A method of estimating an electrical load on an inverter system having a DC link and a converter system, the method comprising the steps of: sensing a voltage of the DC link; evaluating a rate of change of the DC link voltage; and calculating an estimate of an average load current, using the rate of change of the DC link voltage.
Claim 19
Dependent Claim
38 words
The method of claim 15 further comprising the steps of: providing closed loop voltage control for the converter system; and using the estimate of the average load current as a feedback signal for the closed loop voltage control.
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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) | 2002-03-29 | 2002-09-28 | 2003-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-29 | 2006-09-28 | 2007-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-29 | 2010-09-28 | 2011-03-30 | $7700.00 | Window Closed / Lapsed |