DISTRIBUTED INVERTER AND INTELLIGENT GATEWAY

• US 20090000654A1
• Filed: 05/15/2008
• Published: 01/01/2009
• Est. Priority Date: 05/17/2007
• Status: Abandoned Application

• Current Assignee: Enphase Energy Incorporated
• Original Assignee: Larankelo, Inc.
• Inventors: Kapur, Rajan N., Rotzoll, Robert R., Patil, Suhas S.
• Application Number:
  US12/121,616
• Publication Number:
  US 20090000654A1
• Time in Patent Office: Days
• US Class Current: 136/244
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A system and method for converting DC from one or more sources to AC power utilizing a novel partitioning scheme are disclosed. This partitioning scheme is particularly well suited for photovoltaic (PV) microinverter applications. The primary goals are to make installation, operation and maintenance of the system safe and simple. Secondary goals are to improve reliability and lifetime of the converter in a cost effective manner. In one embodiment, the microinverters are placed in one-to-one proximity with the photovoltaic modules, each proximate microinverter incorporating a reduced number of functions and components. Remaining common functions and controls are implemented separately.

Claims

1. A system for transforming energy, comprising:

a plurality of photovoltaic modules;

a plurality of microinverters electrically coupled to the photovoltaic modules in a one-to-one relationship; and

a gateway electrically coupled to the plurality of microinverters, wherein features of the gateway are capable of being upgraded with at least one of hardware, software, and firmware.

2. The system of claim 1, wherein the gateway comprises an interface unit and control unit.

3. The system of claim 1, wherein the interface unit, comprises:

a plurality of sensors to detect dynamic utility grid conditions;

a communication unit to communicate with the plurality of microinverters and the gateway; and

an isolation unit to substantially prevent communication signals from the microinverters from appearing on the utility grid.

4. The system of claim 1, wherein the control unit provides a monitoring functions to monitor the plurality of microinverters.

5. The system of claim 1, wherein each of the plurality of microinverters, comprise:

an inversion unit to convert DC into AC;

a maximum power point tracking (MPPT) unit to optimize power output from the plurality photovoltaic modules;

a communications unit to provide communications to the gateway; and

a safety unit to provide safety functions.

6. The system of claim 1, wherein the communications unit permits communication in at least one of wireless communication, wired communication, and powerline communication.

7. The system of claim 5, wherein the safety unit is capable of disabling the microinverter upon detection of the microinverter being electrically decoupled from either the gateway or the PV module.

8. The system of claim 5, wherein the safety unit is capable of disabling the microinverter in response to a communication signal from the communication unit of the gateway.

9. The system of claim 5, wherein the safety unit is capable of disabling the microinverter upon detection of predetermined grid conditions.

10. The system of claim 9, wherein the predetermined grid conditions include at least one of a low grid voltage, a high grid voltage, a low grid frequency, a high grid frequency and a predetermined change in grid impedance.

11. A gateway for use in a system for use in an energy generating system, comprising:

an interface unit for interfacing with a plurality of microinverters and a utility grid;

a control unit electrically coupled to the interface unit for controlling at least one of safety functionality, synchronization functionality to synchronize the plurality of microinverters to the utility grid, and monitoring functionality to monitor the plurality of microinverters and the utility grid, wherein the control unit is capable of being electrically coupled to an external monitor.

12. The gateway of claim 11, wherein the interface unit, comprises:

a plurality of sensors to detect dynamic utility grid conditions;

a communication unit to communicate with the plurality of microinverters and the control unit; and

an isolation unit to substantially prevent communication signals from the plurality of microinverters from appearing on the utility grid.

13. The system of claim 12, wherein the communications unit is capable of communication in at least one of wireless communication, wired communication, and powerline communication.

14. The system of claim 12, wherein each of the plurality of microinverters includes a safety unit capable of disabling the microinverter upon detection of the microinverter being electrically decoupled from either the gateway or a power module.

15. The system of claim 12, wherein the power module is a wind turbine.

16. The system of claim 12, wherein each of the plurality of microinverters includes a safety unit capable of disabling the microinverter upon detection of predetermined utility grid conditions.

17. A photovoltaic system for transforming radiant energy into alternating current, comprising:

a plurality of photovoltaic modules;

a plurality of microinverters coupled to the photovoltaic modules in a one-to-one relationship, wherein each of the plurality of microinverters comprise;

an inversion unit to convert DC into AC;

a MPPT unit to optimize power from the plurality photovoltaic modules;

a communications unit to provide communications to the gateway; and

a safety unit to provide safety functions;

a gateway coupled to the plurality of microinverters, wherein the gateway comprises;

an interface unit for interfacing with a plurality of microinverters and a utility grid; and

a control unit coupled to the interface unit for controlling at least one of safety functionality, synchronization to synchronize the plurality of microinverters to the utility grid, and monitoring, wherein the control unit is capable of being coupled to an external monitor.

18. The system of claim 17, wherein the interface unit comprises a communications unit permitting communication in at least one of wireless communication, wired communication, and powerline communication.

19. The system of claim 17, wherein the safety unit is capable of disabling the microinverter upon detection of the microinverter being electrically decoupled from either the gateway or a photovoltaic module.

20. The system of claim 17, wherein each of the safety unit is capable of disabling the microinverter upon detection of predetermined utility grid conditions.