System and Method for Flash Bypass

• US 20120217973A1
• Filed: 11/01/2011
• Published: 08/30/2012
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Tigo Energy, Inc
• Inventors: Avrutsky, Mordechay
• Granted Patent: US 8,841,916 B2
• Time in Patent Office: Days
• US Class Current: 324/501
• 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 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A solar photovoltaic panel is disclosed that includes a photovoltaic cell, a local management unit connected between the cell and a string bus, and a bypass device connected to the cell that is operable to bypass the local management unit when conducting a flash test. The panel preferably further includes a transient detector connected to the cell that is operable to sense an output from the cell having a predetermined transient rise time. The transient detector and the bypass device may be contained within a junction box integrated into the panel and may include the local management unit within the junction box. The transient detector may include a switch connected to a circuit that electrically bypasses the local management unit when the switch is turned on as a result of an output transient rise time less than the predetermined time, thus facilitating a flash test of the photovoltaic panel.

Claims

1. A solar photovoltaic panel comprising:

a photovoltaic cell;

a local management unit connected between the cell and a string bus; and

a bypass device connected to the cell operable to bypass the local management unit when conducting a flash test.

2. The panel according to claim 1 further comprising a transient detector connected to the cell operable to sense an output from the cell having a transient rise time less than 500 milliseconds.

3. The panel according to claim 1 wherein the device is a mechanical switch.

4. The panel according to claim 1 wherein the device is a transistor switch.

5. The panel according to claim 2 wherein the transient detector and the bypass device are contained within a junction box integrated into the panel.

6. The panel according to claim 5 wherein the local management unit is also contained within the junction box integrated into the panel.

7. The panel according to claim 2 wherein the transient detector includes a transistor switch connected to the bypass device.

8. The panel according to claim 7 wherein the bypass device is a transistor circuit that electrically bypasses the local management unit when the transistor switch is turned on.

9. The box according to claim 1 wherein the bypass device is a manual switch located in the panel.

10. A smart junction box for connecting a solar photovoltaic cell to an electrical string bus, the junction box comprising:

a local management unit connected to one or more cells; and

a bypass device for electrically bypassing the local management unit and connecting the cell directly to an electrical string bus during a flash test.

11. The box according to claim 10 wherein the bypass device comprises an electronic circuit including a transistor switch and a transient detector operably connected to the switch.

12. The box according to claim 11 wherein the transient detector is operably connected between the cell and the transistor switch to actuate the switch upon sensing a cell output rise time of less than about 100 milliseconds indicative of a light flash.

13. The box according to claim 10 wherein the bypass device is a reed switch.

14. The box according to claim 10 wherein the bypass device is a transistor circuit having a switch that electrically bypasses the local management unit when the transistor switch is turned on.

15. The box according to claim 14 further comprising a transient detector operably connected between the cell and the circuit to automatically actuate the switch upon sensing a cell output rise time of less than about 500 milliseconds indicative of a light flash.

16. A method of performing a flash test on a solar photovoltaic panel having a local management unit connected between the cell and a string bus, the method comprising:

providing a light flash source facing the panel;

providing a bypass device around the local management unit;

bypassing the local management unit;

applying a light flash to the panel; and

measuring the output of the cell during the light flash.

17. The method of claim 16 wherein the bypass device and the local management unit are integral with the panel.

18. The method of claim 16 wherein bypassing comprises:

detecting a cell output signal indicative of a light flash;

activating a bypass switch in response to the signal to complete an electrical path from the cell around the local management unit; and

receiving the cell output signal.

19. The method of claim 18 further comprising automatically activating the bypass switch upon detection of an output signal rise time from the cell to a predetermined level in less than 100 milliseconds.

20. The method of claim 19 wherein the rise time is less than about 10 milliseconds.