Central inverters

• US 9,300,133 B2
• Filed: 07/08/2014
• Issued: 03/29/2016
• Est. Priority Date: 08/22/2007
• Status: Active Grant

• Current Assignee: Maxout Renewables, Inc.
• Original Assignee: Maxout Renewables, Inc.
• Inventors: Cummings, Eric Bryant
• Primary Examiner(s): CAVALLARI, DANIEL J
• Application Number:
  US14/326,222
• Publication Number:
  US 20140319917A1
• Time in Patent Office: 630 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 31/02021 for solar cells electrical connection means, e.g. junction boxes, specially adapted for structural association with photovoltaic modules H02S40/34
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 1/106 for load balancing, symmetrisation, or sharing
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02M 1/0043 Converters switched with a phase shift, i.e. interleaved non-isolated DC/DC converters H02M3/1586
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Various techniques are employed alone or in combination, to reduce the levelized cost of energy imposed by a power plant system. Solar energy concentrators in the form of inflated reflectors, focus light onto photovoltaic receivers. Multiple concentrators are grouped into a series-connected cluster that shares control circuitry and support structure. Individual concentrators are maintained at their maximum power point via balance controllers that control the flow of current that shunts this series connection. DC current from clusters is transmitted moderate distances to a centralized inverter. The inductance of transmission lines is maximized using an air-spaced twisted pair, enhancing the performance of boost-type three phase inverters. Cluster outputs are separate from individual inverters in massively interleaved arrays co-located at a central location. Step-up transformers convert inverter voltages to grid voltages, and small transformers provide isolation and voltage step-up only on receiver-to-receiver imbalance currents, typically <20% of the total current.

Claims

1. A central inverter comprising:

a housing;

a plurality of individual inverters each removably coupled to a rack inside the housing, each of the plurality of individual inverters having an input and an output, the input of each individual inverter for providing electrical coupling to at least one of a plurality of photovoltaic receivers disposed remote from the housing, and the output of each individual inverter for providing an AC output;

a cooling apparatus configured to provide common cooling to each of the plurality of individual inverters, wherein the cooling apparatus is configured to cool one or more of the plurality of inverters by producing a jet of water that impinges on a cooling plate that is in thermal communication with the one or more of the plurality of individual inverters;

timing circuitry electrically coupled to each of the plurality of individual inverters, the timing circuitry configured to provide switch timing and synchronization between the plurality of individual inverters; and

a central output for combining the AC output from each of the plurality of individual inverters.

2. The central inverter of claim 1 wherein each of the plurality of individual inverters includes at least one of a removably coupled capacitor module or a removably coupled switch module.

3. The central inverter of claim 1, wherein the jet is hydrostatically pressurized.

4. The central inverter of claim 1, wherein the cooling plate is coupled to materials in thermal communication with a heat generator.

5. The central inverter of claim 1, further comprising a second housing that is coupled to the housing and houses at least one of a radiator or a fan.

6. The central inverter of claim 1, wherein the housing includes a plurality of vents at a first side of the housing and a pipe extending from a second side of the housing.

7. The central inverter of claim 1, wherein an individual inverter of the plurality of individual inverters includes a switch enabling it to provide power to one or more of the plurality of photovoltaic receivers.

8. A central inverter comprising:

a housing;

a plurality of individual inverters each removably coupled to a rack inside the housing, each of the plurality of individual inverters having an input and an output, the input of each individual inverter for providing electrical coupling to at least one of a plurality of photovoltaic receivers disposed remote from the housing, and the output of each individual inverter for providing an AC output, wherein each of the plurality of individual inverters includes a series input inductor to reduce an output ripple current of the central inverter;

a cooling apparatus configured to provide common cooling to each of the plurality of individual inverters;

timing circuitry electrically coupled to each of the plurality of individual inverters, the timing circuitry configured to provide switch timing and synchronization between the plurality of individual inverters, the switch timing coordinated using daisy-chained handshaking signal; and

a central output for combining the AC output from each of the plurality of individual inverters.

9. The central inverter of claim 8, wherein the switch timing is determined using a clock signal from a microcontroller.

10. The central inverter of claim 8, wherein the switch timing is coordinated using a handshaking signals.

11. The central inverter of claim 8, wherein each of the plurality of individual inverters includes at least one of a removably coupled capacitor module or a removably coupled switch module.

12. The central inverter of claim 8, wherein the housing includes a plurality of vents at a first side of the housing and a pipe extending from a second side of the housing.

13. The central inverter of claim 8, wherein an individual inverter of the plurality of individual inverters includes a switch enabling it to provide power to one or more of the plurality of photovoltaic receivers.

14. A central inverter comprising:

a housing;

a plurality of individual inverters each removably coupled to a rack inside the housing, each of the plurality of individual inverters having an input and an output, the input of each individual inverter for providing electrical coupling to at least one of a plurality of photovoltaic receivers disposed remote from the housing, and the output of each individual inverter for providing an AC output;

a cooling apparatus configured to provide common cooling to each of the plurality of individual inverters;

timing circuitry electrically coupled to each of the plurality of individual inverters, the timing circuitry configured to provide switch timing and synchronization between the plurality of individual inverters;

a central output for combining the AC output from each of the plurality of individual inverters; and

a robotic mechanism controllable to perform at least one of;

removing individual inverters from the rack, placing individual inverters in the rack, or actuating a switch associated with one or more of the plurality of individual inverters.

15. The central inverter of claim 14, wherein each of the plurality of individual inverters includes at least one of a removably coupled capacitor module or a removably coupled switch module.

16. The central inverter of claim 14, wherein the housing includes a plurality of vents at a first side of the housing and a pipe extending from a second side of the housing.

17. The central inverter of claim 14, wherein an individual inverter of the plurality of individual inverters includes a switch enabling it to provide power to one or more of the plurality of photovoltaic receivers.