Sensor Device for Monitoring the Operation of a PV System, and PV System with Such a Sensor Device

• US 20080030354A1
• Filed: 05/27/2005
• Published: 02/07/2008
• Est. Priority Date: 06/04/2004
• Status: Abandoned Application

• Current Assignee: Hendrik Oldenkamp
• Original Assignee: Hendrik Oldenkamp
• Inventors: Oldenkamp, Hendrik
• Application Number:
  US11/628,362
• Publication Number:
  US 20080030354A1
• Time in Patent Office: Days
• US Class Current: 340/635
• CPC Class Codes: H01L 31/0504 specially adapted for series or parallel connection of solar cells in a module
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: H02S 50/15 using optical means, e.g. using electroluminescence
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A sensor device (5) for monitoring the operation of a PV system is described. Such a PV system has at least, one PV module (1) with a plurality of PV cells (3) laminated on a support plate (2). The sensor device (5) comprises a substrate (6) with an electronic circuitry (9) adapted to be mounted on the support plate adjacent to PV cells of the PV module. The circuitry comprises two or more input terminals (7,8) for receiving an output voltage of a series connection of one or more PV cells of a PV module, and a comparator (T₁,T₂) for comparing the output voltage received on the input terminals with a first reference voltage corresponding with a first operation level of the PV module. The comparator controls a first signalling element (12) for signalling the operation of the PV module above said first operation level.

Claims

1. Sensor device (5) for monitoring the operation of a PV system, said PV system having at least one PV module (1) with a plurality of PV cells (3) laminated on a support plate (2), characterized by a substrate with an electronic circuitry (9) adapted to be mounted on the support plate adjacent to PV cells of the PV module, said circuitry comprising two or more input terminals (7,8) for receiving an output voltage of a series connection of one or more PV cells of a PV module, and a comparator (T₁,T₂;

U₂,U₃) for comparing the output voltage received on the input terminals with a first reference voltage corresponding with a first operation level of the PV module, the comparator controlling a first signalling element (12;

20,21) for signalling the operation of the PV module above said first operation level.

2. Sensor device according to claim 1, wherein said comparator (T₁,T₂;

U₂,U₃) is operable to compare the output voltage received on the input terminals with a second reference voltage corresponding with a second operation level of the PV module (1), wherein the comparator is controlling a second signalling element (13) for signalling operation of the PV module above said second operation level.

3. Sensor device according to claim 1, wherein the comparator comprises a temperature compensation element (T₁,D₁;

D₁) operable to vary the reference voltage(s) in dependence on the temperature of the PV module (1), wherein the temperature coefficient of the temperature compensation element corresponds to the temperature coefficient of the PV cells (3).

4. Sensor device according to claim 1, wherein the comparator (T₁,T₂;

U₂,U₃) comprises a solar irradiation compensation element (D₉) operable to vary the reference voltage in dependence on the solar radiation of the PV module (1), wherein the spectral response of the solar irradiation compensation element corresponds with the spectral response of the PV cells (3).

5. Sensor device according to claim 3, wherein the comparator (T₁,T₂;

U₂,U₃) comprises a semiconductor element (T₁,D₁;

D₁), preferably a semiconductor element of the same type as the PV cells (3), with a pn-junction determining the first reference voltage, wherein said pn-junction also operates as said temperature compensation element.

6. Sensor device according to claim 5, wherein the comparator comprises a light sensitive photo element (D₉), wherein the photo current of the photo element flows through the pn-junction of the semiconductor element (D₁).

7. Sensor device according to claim 6, wherein the comparator further comprises a modification arrangement (U₁, R_ph1, R_ph2) for amplifying or reducing the photo current

8. Sensor device according to claim 5, wherein the electronic circuitry comprises a first transistor (T₁), a first diode (D₁), preferably a Schottky diode, connected to the emitter of the first transistor, a first voltage divider (R₁,R₂) having its tap connected to the base of the first transistor, and a first LED (D₂) connected as first signalling element (12) to the collector of the first transistor, wherein the series connection of the first LED, the c-e section of the first transistor and the first diode, and the voltage divider are connected to the input terminals of the electronic circuitry.

9. Sensor device according to claim 8, wherein a second transistor (T₂) and a second LED (D₃) connected as second signalling element (13) to the collector of the second transistor, are connected parallel to the first LED (D₁), wherein a second voltage divider (R₃,R_4,5) is provided having its tap connected to the base of the second transistor, wherein the tap voltage of the second voltage divider (R₃,R_4,5) lies at a higher level as the tap voltage of the first voltage divider (R₁,R₂), wherein the forward voltage of the second LED is lower than the forward voltage of the first LED.

10. Sensor device according to claims 6, wherein said photo element is a photo diode (D₉) connected in series with the first diode (D₁), wherein preferably a resistor (R₁₁) simulating the shunt resistance of a series of PV cells (3) is connected parallel to the first diode, wherein the junction of the photo diode and the first diode is coupled to the emitter of the first transistor (T₁) through a transistor pair (T₃,T₄).

11. Sensor device according to claim 6, wherein said photo element is a photo diode (D₉) connected in series with the first diode (D₁), wherein preferably a resistor (R₁₁) simulating the shunt resistance of a series of PV cells (3) is connected parallel to the first diode.

12. Sensor device according to claim 1, wherein the comparator comprises a temperature compensation element (D₁) operable to vary the reference voltage(s) in dependence on the temperature of the PV module (1).

13. Sensor device according to claim 12, wherein said electronic circuitry comprises a photo diode for supplying a photo current and said electronic circuitry is arranged to supply a correction voltage.

14. Sensor device according to claim 1, comprising an infrared light-emissive signalling element (21)

15. Sensor device according to claim 1, wherein the substrate (2) of the electronic circuitry (9) is provided with extensions carrying the input terminals (7,8) adapted to be connected to the back side of adjacent cells (3).

16. Sensor according to claim 1, wherein the substrate (9) of the electronic circuitry (9) is provided with positioning parts (10) for positioning the substrate between PV cells (3).

17. PV system, comprising at least one PV module (1) with a number of series connected PV cells (3), characterized in that said at least one PV module is provided with a sensor device (5) according claim 1.

18. PV system according to claim 12, wherein the input terminals (7,8) of the electronic circuitry (9) are connected to a series connection of only a part of all PV cells (3) of the module (1), for example a series of 12-18 PV cells.