Solar panel disconnect and reactivation system

• US 10,566,798 B2
• Filed: 03/31/2016
• Issued: 02/18/2020
• Est. Priority Date: 03/31/2016
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Kim, Il Han, Lu, Xiaolin
• Primary Examiner(s): Jager, Ryan
• Application Number:
  US15/087,216
• Publication Number:
  US 20170288408A1
• Time in Patent Office: 1,419 Days
• Field of Search: 307 80
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• 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 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: H02S 40/32 comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
• CPC Class Codes: H02S 40/34 comprising specially adapted electrical connection means to be structurally associated with the PV module, e.g. junction boxes
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

A photovoltaic system with an inverter, at least one solar panel for providing electrical power, and electrical wiring for coupling electrical power from the at least one solar panel to the inverter. Also included is a transmitter for transmitting a messaging protocol along the electrical wiring, where the protocol includes a multibit wireline signal. Also included is circuitry for selectively connecting the electrical power from the at least one solar panel along the electrical wiring to the inverter in response to the messaging protocol.

Claims

1. A photovoltaic system, comprising:

a power source;

circuitry arranged to selectively couple the power source to electrical wiring of a power grid;

a receiver coupled to the power grid in parallel with the circuitry and further coupled to the circuitry, wherein;

the receiver includes a counter;

the receiver is for;

listening, over the electrical wiring, for a multibit wireline signal in a frequency shift keying (FSK) modulated messaging protocol from a transmitter of an inverter, in which a mark frequency indicates a first bit value and a space frequency indicates a second bit value;

incrementing the counter in response to the multibit wireline signal; and

resetting the counter in response to a failure to receive the multibit wireline signal; and

the circuitry is for selectively coupling the power source to the electrical wiring and thereby to the inverter, in response to the counter exceeding a threshold.

2. The photovoltaic system of claim 1, wherein the circuitry comprises a maximum power point tracker associated with the power source, wherein the receiver is for communicating the multibit wireline signal to the maximum power point tracker for disconnecting the power source to the electrical wiring.

3. The photovoltaic system of claim 1:

wherein the FSK modulated messaging protocol comprises a plurality of multibit time domain messages; and

wherein the circuitry is further for disconnecting the power source from the electrical wiring in response to an absence of detecting one of the plurality of multibit time domain messages during a period of time.

4. The photovoltaic system of claim 1:

wherein the FSK modulated messaging protocol comprises a plurality of multibit time domain messages;

wherein each of the plurality of multibit time domain messages is in a respective one of a plurality of predetermined periods of time; and

wherein the circuitry is further for disconnecting the power source from the electrical wiring in response to an absence of detecting one of the plurality of multibit time domain messages during one of the plurality of predetermined periods of time.

5. The photovoltaic system of claim 4:

wherein the circuitry is further for disconnecting the power source from the electrical wiring in response to an absence of detecting one of the plurality of multibit time domain messages in a majority of the plurality of predetermined periods of time in a group of predetermined periods of time.

6. The photovoltaic system of claim 5, wherein the plurality of multibit time domain messages is in a set of pseudo-orthogonal signals.

7. The photovoltaic system of claim 5, wherein the group of predetermined periods of time is seven predetermined periods of time.

8. The photovoltaic system of claim 5, wherein the group of predetermined periods of time is nine predetermined periods of time.

9. The photovoltaic system of claim 1:

wherein the FSK modulated messaging protocol comprises a plurality of multibit time domain messages;

wherein each of the plurality of multibit time domain messages is in one of a plurality of predetermined periods of time; and

wherein the circuitry is for coupling the power source to the electrical wiring further in response to detecting one of the plurality of multibit time domain messages during the predetermined period of time.

10. The photovoltaic system of claim 9:

wherein the circuitry is further for coupling the power source to the electrical wiring further in response to detecting one of the plurality of multibit time domain messages in a majority of the plurality of predetermined periods of time in a group of predetermined periods of time.

11. The photovoltaic system of claim 1, further comprising:

the inverter coupled to the power grid; and

the transmitter coupled to the power grid in parallel with the inverter.

12. The photovoltaic system of claim 11, wherein the inverter comprises an actuator.

13. The photovoltaic system of claim 12, wherein the actuator is operated in response to detecting an electrical spike or is user operated.

14. The photovoltaic system of claim 1, further comprising:

a plurality of solar panels that includes the power source, wherein the electrical wiring of the power grid is for coupling electrical power from the plurality of solar panels to the inverter; and

a plurality of circuitry for selectively coupling electrical power from any solar panel of the plurality of solar panels along the electrical wiring, in response to the multibit wireline signal.

15. The photovoltaic system of claim 14, wherein the multibit wireline signal instructs the plurality of circuitry to couple a first subset of the plurality of solar panels to the electrical wiring, and at a same time to disconnect a second subset of the plurality of solar panels from the electrical wiring.

16. The photovoltaic system of claim 14, wherein the plurality of circuitry is operable to couple a first subset of the plurality of solar panels to the electrical wiring, in response to a first pseudo-orthogonal bit sequence in the multibit wireline signal, and at a same time to disconnect a second subset of the plurality of solar panels from the electrical wiring in response to a second pseudo-orthogonal bit sequence in the multibit wireline signal.

17. The photovoltaic system of claim 1, wherein the multibit wireline signal consists of data bits.

18. The photovoltaic system of claim 1, wherein a plurality of multibit wireline signals of the FSK modulated messaging protocol are transmitted without a time space between consecutive signals of the plurality of multibit wireline signals and with a continuous phase transition.

19. The photovoltaic system of claim 1, wherein the receiver is further for decoding the multibit wireline signal to determine whether the multibit wireline signal contains a sequence assigned to the receiver, and the circuitry is for selectively coupling the power source to the electric wiring in response to the multibit wirelines signal containing the sequence assigned to the receiver.

20. A method of operating a photovoltaic system, the method comprising:

listening, by a receiver, for a multibit wireline signal in frequency shift keying (FSK) modulated messaging protocol from a transmitter of an inverter provided over a power grid, in which a mark frequency indicates a first bit value and a space frequency indicates a second bit value;

incrementing a counter based on receiving the multibit wireline signal;

resetting the counter based on a failure to receive the multibit wireline signal; and

selectively connecting, by circuitry, electrical power from a power source to the power grid in response to the counter exceeding a threshold.

21. A photovoltaic system, comprising:

an inverter coupled to a power grid to provide an output power signal from the power grid, wherein the inverter has first and second inputs and first and second outputs; and

a transmitter coupled between the first and second inputs of the inverter, the transmitter configured to transmit a multibit wireline signal in a frequency shift keying (FSK) modulated messaging protocol, in which a mark frequency indicates a first bit value and a space frequency indicates a second bit value;

a set of coupling circuits coupled in series between the first and second inputs of the inverter and in parallel with the transmitter; and

a set of receivers coupled between the first and second inputs of the inverter such that each receiver is coupled in parallel with a respective coupling circuit of the set of coupling circuits, wherein;

each receiver of the set of receivers includes a counter;

each receiver of the set of receivers is configured to;

receive the multibit wireline signal;

increment the counter in response to receiving the multibit wireline signal; and

reset the counter in response to a failure to receive the multibit wireline signal; and

each coupling circuit of the set of coupling circuits is configured to couple a power source to the inverter in response to the counter of a respective receiver of the set of receivers exceeding a threshold.