Solar photovaltaic module rapid shutdown and safety system

• US 9,941,421 B2
• Filed: 10/24/2015
• Issued: 04/10/2018
• Est. Priority Date: 10/19/2009
• Status: Active Grant

• Current Assignee: Helios Focus, LLC
• Original Assignee: Helios Focus, LLC
• Inventors: Dunton, Randy R., Sutton, Geoffrey
• Primary Examiner(s): Fleming, Fritz M
• Assistant Examiner(s): PARRIES, DRU M
• Application Number:
  US14/922,123
• Publication Number:
  US 20160126367A1
• Time in Patent Office: 899 Days
• Field of Search: 307115
• 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: 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: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 17/7955 using phototransistors
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A photovoltaic (PV) module safety shutdown system includes a module-on switch coupled with a PV module coupled with an alternating current (AC) mains panel through an inverter. A system monitor couples with the module-on switch and with the AC mains panel and generates a system-on signal. A module discharge switch couples with an inherent capacitance of the inverter and with the system monitor. The module discharge switch discharges the inherent capacitance, by coupling the inherent capacitance with a discharge element, in response to the system monitor not generating the system-on signal. In implementations a module short switch shorts the PV module in response to a passage of a predetermined amount of time after the module discharge switch is switched on. The module-on switch, module discharge switch, and module short switch may be included in a junction box of the PV module and coupled with the system monitor through multiple opto-isolators.

Claims

1. A solar photovoltaic (PV) module safety shutdown system, comprising:

a module-on switch operatively coupled with a photovoltaic (PV) module, the PV module coupled with an alternating current (AC) mains panel through an inverter;

a system monitor operatively coupled with the module-on switch and with the AC mains panel, the system monitor configured to generate a system-on signal, and;

a module discharge switch operatively coupled with an inherent capacitance of the inverter and with the system monitor;

wherein the module discharge switch discharges the inherent capacitance, by coupling the inherent capacitance with a discharge element, in response to the system monitor not generating the system-on signal.

2. The system of claim 1, further comprising a module short switch that shorts the PV module in response to a passage of a predetermined amount of time after the module discharge switch is switched on.

3. The system of claim 1, wherein the module-on switch and the module discharge switch are comprised in a junction box of the PV module.

4. The system of claim 3, wherein the junction box comprises a plurality of sockets configured to receive system-on signal cables.

5. The system of claim 1, wherein the module-on switch and module discharge switch are coupled with the system monitor through one or more opto-isolators.

6. The system of claim 1, wherein one of a timer and a light sensor is coupled with the system monitor and the system monitor is configured to, using the one of a timer and light sensor, cease generating the system-on signal during nighttime hours.

7. The system of claim 1, wherein the PV module does not comprise a direct current (DC) optimizer.

8. The system of claim 1, wherein the PV module does not comprise a microinverter.

9. A solar photovoltaic (PV) module safety shutdown system, comprising:

a photovoltaic (PV) module comprising a module-on switch, a module discharge switch, and a module short switch operatively coupled thereto, the PV module further coupled with an alternating current (AC) mains panel through an inverter, the PV module further coupled with a system monitor;

wherein the system monitor is configured to generate a system-on signal and to supply the system-on signal to the PV module;

wherein the module-on switch is configured to disable the PV module through disconnecting the PV module from an electrical circuit in response to the PV module not receiving the system-on signal;

wherein the module discharge switch discharges an inherent capacitance of the inverter by coupling the inherent capacitance with a discharge element in response to the PV module not receiving the system-on signal, and;

wherein the module short switch shorts the PV module in response to a passage of a predetermined amount of time after the PV module stops receiving the system-on signal.

10. The system of claim 9, wherein the module-on switch, the module discharge switch, and the module short switch are comprised in a junction box of the PV module.

11. The system of claim 10, wherein the junction box comprises a plurality of sockets configured to receive system-on signal cables.

12. The system of claim 9, wherein the module-on switch, the module discharge switch, and the module short switch are coupled with the system monitor through one or more opto-isolators.

13. The system of claim 9, wherein the PV module does not comprise a direct current (DC) optimizer and wherein the PV module does not comprise a microinverter.

14. A solar photovoltaic (PV) module safety shutdown system, comprising:

a first photovoltaic (PV) module comprising a first module-on switch and a first module discharge switch, the first PV module operatively coupled with an alternating current (AC) mains panel through an inverter;

a second PV module comprising a second module-on switch and a second module discharge switch, the second PV module operatively coupled with the AC mains panel through the inverter, and;

a system monitor operatively coupled with the first PV module, the second PV module, and the AC mains panel, the system monitor configured to generate a system-on signal and supply the system-on signal to the first PV module and the second PV module;

wherein, in response to the first PV module not receiving the system-on signal, the first module discharge switch discharges an inherent capacitance of the inverter by coupling the inherent capacitance with a first discharge element, and;

wherein, in response to the second PV module not receiving the system-on signal, the second module discharge switch discharges the inherent capacitance of the inverter by coupling the inherent capacitance with a second discharge element.

15. The system of claim 14, wherein the first module-on switch is configured to disable the first PV module through disconnecting the first PV module from an electrical circuit in response to the first PV module not receiving the system-on signal, and wherein the second module-on switch is configured to disable the second PV module through disconnecting the second PV module from an electrical circuit in response to the second PV module not receiving the system-on signal.

16. The system of claim 14, wherein the first PV module comprises a first module short switch that shorts the first PV module in response to a passage of a predetermined amount of time after the first module discharge switch is turned on, and wherein the second PV module comprises a second module short switch that shorts the second PV module in response to a passage of a predetermined amount of time after the second module discharge switch is turned on.

17. The system of claim 14, wherein the first module-on switch and the first module discharge switch are comprised in a first junction box of the first PV module, and wherein the second module-on switch and the second module discharge switch are comprised in a second junction box of the second PV module.

18. The system of claim 17, wherein the first junction box comprises a plurality of sockets configured to receive system-on signal cables, and wherein the second junction box comprises a plurality of sockets configured to receive system-on signal cables.

19. The system of claim 14, wherein the first module-on switch, the second module-on switch, the first module discharge switch, and the second module discharge switch are coupled with the system monitor through one or more opto-isolators.

20. The system of claim 14, wherein the system does not comprise a direct current (DC) optimizer and wherein the system does not comprise a microinverter.