US6369461B1
Expired / Lapsed
US
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High efficiency power conditioner employing low voltage DC bus and buck and boost converters
Assignee: ABB Inc USA
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Filing: 2000-09-01
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Granted: 2002-04-09
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Expires: 2020-09-01
Abstract
Abstract A power conditioner interfaces a load to a fuel cell 10 that produces a low voltage that varies with the load. A dc-to-ac inverter 16 operates with a low voltage input provided by a dc bus 14 . When a positive step load change occurs, a low voltage battery 22 provides power equal to the step change until the fuel cell 10 is able to provide enough power to support the entire load. The power from the battery 22 is supplied to the varying dc bus 14 through a boost converter 12 . When very large positive load step changes occur, the battery can feed power to the dc bus through diode D 1 , rather than through the boost converter. Diode D 1 does not need to be used, but its use allows the boost converter to be sized for common load changes rather than for the maximum possible load change (such as might be seen during a faulted output). A buck converter converts the variable voltage on the dc bus 14 to the appropriate float charging voltage of the battery. The buck converter also supplies power for auxiliary equipment when available from the fuel cell. If the fuel cell is unable to provide the auxiliary power (such as during startup or load transients), then the auxiliary power can come directly from the battery.
Inventors
- 👤 Aaron M. Jungreis
- 👤 Vinod Bapat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:37
CPC Classifications
H; H02; H02J; H02J1/00; H02J1/10; H01; H01M; H01M16/00; H01M16/003; H02J7/00; H02J7/34; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
67 words
A power conditioner for conditioning electrical power provided by a fuel cell to a load through a dc-to-ac inverter, comprising: (a) a dc bus coupled to the fuel cell and the dc-to-ac inverter; (b) a battery operatively coupled to the dc bus; (c) a buck converter coupled between the battery and the dc bus; and (d) a boost converter coupled between the battery and the dc bus.
Claim 2
Dependent Claim
67 words
A power conditioner for conditioning electrical power provided by a fuel cell to a load through a dc-to-ac inverter, comprising: (a) a dc bus coupled to the fuel cell and the dc-to-ac inverter; (b) a battery operatively coupled to the dc bus; (c) a buck converter coupled between the battery and the dc bus; and (d) a boost converter coupled between the battery and the dc bus.
Claim 3
Dependent Claim
36 words
A power conditioner as recited in claim 1 , wherein a low side of the buck converter is coupled to the battery and a high side of the buck converter is coupled to the dc bus.
Claim 4
Dependent Claim
36 words
A power conditioner as recited in claim 2 , wherein a low side of the boost converter is coupled to the battery and a high side of the boost converter is coupled to the dc bus.
Claim 5
Dependent Claim
24 words
A power conditioner as recited in claim 3 , further comprising a diode (D 1 ) coupled between the battery and the dc bus.
Claim 6
Dependent Claim
42 words
A power conditioner as recited in claim 4 , wherein the diode is configured such that, when very large positive load step changes occur, the battery can feed power to the dc bus through the diode rather than through the boost converter.
Claim 7
Dependent Claim
33 words
A power conditioner as recited in claim 1 , wherein the dc-to-ac inverter is designed to operate with a low voltage input, and the low voltage input is provided by the dc bus.
Claim 8
Dependent Claim
48 words
A power conditioner as recited in claim 1 , wherein, when a positive step load change occurs, the battery provides power, through the boost converter and dc bus, equal to the step change until the fuel cell is able to provide enough power to support the entire load.
Claim 9
Dependent Claim
47 words
A power conditioner as recited in claim 7 , wherein the boost converter permits control of the battery power so that the power drawn from the fuel cell can be gradually increased as the ability of the fuel cell to produce the required load power gradually increases.
Claim 10
Dependent Claim
38 words
A power conditioner as recited in claim 8 , wherein, when very large positive load step changes occur, the battery feeds power to the dc bus through a diode (D 1 ) rather than through the boost converter.
Claim 11
Dependent Claim
39 words
A power conditioner as recited in claim 9 , wherein, when the fuel cell has enough reserve power to both charge the battery and supply all of the load power, the buck converter provides charging current to the battery.
Claim 12
Dependent Claim
29 words
A power conditioner as recited in claim 10 , wherein the buck converter converts a variable voltage on the dc bus to a float charging voltage of the battery.
Claim 13
Dependent Claim
25 words
A power conditioner as recited in claim 11 , wherein the buck converter further supplies power for auxiliary equipment when available from the fuel cell.
Claim 14
Dependent Claim
76 words
A power conditioner as recited in claim 12 , wherein a low side of the buck converter is coupled to the battery and a high side of the buck converter is coupled to the dc bus; wherein a low side of the boost converter is coupled to the battery and a high side of the boost converter is coupled to the dc bus; and wherein the diode is coupled between the battery and the dc bus.
Claim 15
Dependent Claim
84 words
A power conditioner for conditioning electrical power provided to a load, comprising: a dc-to-ac inverter having an output providing ac output power for the load; a low voltage, variable dc bus coupled to a power generation device and the dc-to-ac inverter; a low voltage energy storage medium operatively coupled to the dc bus; a buck converter coupled between the low voltage energy storage medium and the dc bus; and a boost converter coupled between the low voltage energy storage medium and the dc bus.
Claim 16
Dependent Claim
84 words
A power conditioner for conditioning electrical power provided to a load, comprising: a dc-to-ac inverter having an output providing ac output power for the load; a low voltage, variable dc bus coupled to a power generation device and the dc-to-ac inverter; a low voltage energy storage medium operatively coupled to the dc bus; a buck converter coupled between the low voltage energy storage medium and the dc bus; and a boost converter coupled between the low voltage energy storage medium and the dc bus.
Claim 17
Dependent Claim
31 words
A power conditioner as recited in claim 14 , wherein the energy storage medium is a member of a group consisting of a battery, electrolytic capacitor, super capacitor, and flywheel system.
Claim 18
Dependent Claim
25 words
A power conditioner as recited in claim 15 , further comprising one or more energy storage media that are paralleled with the power generation device.
Claim 19
Dependent Claim
22 words
A power conditioner as recited in claim 16 , wherein the energy storage media are directly paralleled and have identical voltage output.
Claim 20
Dependent Claim
38 words
A power conditioner as recited in claim 16 , wherein the energy storage media are indirectly paralleled by coupling their respective output to a bus via an accompanying buck and boost converter to tie into the dc bus.
Claim 21
Dependent Claim
51 words
A power conditioner as recited in claim 18 , wherein a fuel cell is coupled in parallel with one of an electrolytic capacitor and a flywheel system, and the fuel cell has a maximum operating voltage that is less than a minimum operating voltage of the electrolytic capacitor and flywheel system.
Claim 22
Dependent Claim
21 words
A power conditioner as recited in claim 14 , wherein the buck and boost converters are combined into a bidirectional converter.
Claim 23
Dependent Claim
18 words
A power conditioner as recited in claim 14 , wherein the low voltage power supply comprises a battery.
Claim 24
Dependent Claim
33 words
A power conditioner as recited in claim 14 , wherein the boost converter includes an air-core switching inductor, wherein the air-core inductor is able to pass high over-currents for short periods of time.
Claim 25
Dependent Claim
21 words
A power conditioner as recited in claim 1 , wherein the buck and boost converters are combined into a bi-directional converter.
Claim 26
Dependent Claim
40 words
A power conditioner as recited in claim 1 , wherein the fuel cell is coupled in parallel with an energy storage medium and has a maximum operating voltage that is less than a minimum operating voltage of the storage medium.
Claim 27
Dependent Claim
33 words
A power conditioner as recited in claim 1 , wherein the boost converter includes an air-core switching inductor, wherein the air-core inductor is able to pass high over-currents for short periods of time.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-04-08 | 2005-10-08 | 2006-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-04-08 | 2009-10-08 | 2010-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-04-08 | 2013-10-08 | 2014-04-09 | $7700.00 | Window Closed / Lapsed |