Solar photovoltaic panel fault detection system

Abstract

The invention discloses a solar photovoltaic panel fault detection system which comprises a voltage signal acquisition module, a fault detection module, a battery pack fault indication module and a power supply circuit module. Wherein the voltage signal acquisition module is used for acquiring voltage signals of positive electrodes of n groups of solar cells, processing the voltage signals of the positive electrodes of the n groups of solar cells and then sending the processed voltage signals to the fault detection module, n is greater than or equal to 2, and n is a positive integer; the fault detection module is used for judging whether at least one group of fault solar cells exist in the (n-1) groups of solar cells according to the processed voltage signals of the positive electrodes of the n groups of solar cells; the power supply circuit module is connected in parallel with the anodes of the n groups of solar cells and is used for reducing the voltage output by the solar cells and then supplying power to the fault detection module and the battery pack fault indication module; the battery pack fault indication module is used for sending out a first indication signal when the fault detection module judges that at least one group of fault solar cells exist in the (n-1) groups of solar cells.

Description

Technical Field

[0001] The present invention relates to the technical field of solar energy fault detection, and in particular to a solar photovoltaic panel fault detection system. Background Art

[0002] The smallest component of a solar photovoltaic power station is a solar photovoltaic panel. Each solar photovoltaic panel is composed of three or more groups of solar cells connected in series. Multiple solar photovoltaic panels are connected in series to achieve the required high voltage for subsequent grid-connected power generation, so each solar photovoltaic power station is generally composed of thousands or tens of thousands of solar photovoltaic panels.

[0003] Currently, when a solar cell in a solar photovoltaic panel fails, the unidirectional conduction principle of a diode can be used to isolate the faulty solar cell from the solar photovoltaic panel system, but it is impossible to discover and find the solar photovoltaic panel with the faulty solar cell among many solar photovoltaic panels.

[0004] Solar photovoltaic power stations are built in the suburbs, with harsh natural environments and a huge number of solar panels. It takes a lot of manpower, material resources and time to find the solar photovoltaic panels with faulty solar cells. Therefore, the current management method of solar photovoltaic power stations is to ignore the problem of solar photovoltaic panels with faulty solar cells. Only when the number of faulty solar cells reaches a certain number and affects the power generation efficiency of the power station, will the location of the faulty photovoltaic panels be roughly estimated and replaced. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a solar photovoltaic panel fault detection system, which can monitor the working status of each group of solar cells and accurately indicate and mark the faulty solar panels and their locations.

[0006] A solar photovoltaic panel fault detection system includes a voltage signal acquisition module, a fault detection module, a battery pack fault indication module and a power supply circuit module; wherein:

[0007] The voltage signal acquisition module is used to collect voltage signals of the positive electrodes of n groups of solar cells, and process the voltage signals of the positive electrodes of n groups of solar cells and send them to the fault detection module, where n≥2, and n is a positive integer;

[0008] The fault detection module is used to determine whether at least one group of faulty solar cells exists in the n-1 groups of solar cells according to the processed voltage signals of the positive electrodes of the n groups of solar cells;

[0009] The power circuit module is connected in parallel with the positive electrodes of the n groups of solar cells, and is used to step down the voltage output by the solar cells and then supply power to the fault detection module and the battery group fault indication module;

[0010] The battery group fault indication module is used to send a first indication signal when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

[0011] Further, the system also includes a wireless communication module;

[0012] The wireless communication module is used to send corresponding fault status information to the monitoring system when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

[0013] Furthermore, the wireless communication module includes a Lora module.

[0014] Furthermore, the battery pack fault indication module includes a first light emitting diode.

[0015] Further, the system also includes a power status indication module;

[0016] The power status indication module is used to send out a second indication signal when at least one group of solar cells is normal, and to send out a third indication signal when all n groups of solar cells are faulty.

[0017] Furthermore, the power status indication module includes a second light emitting diode.

[0018] Further, the system also includes a sleep trigger module;

[0019] The sleep trigger module is connected to the fault detection module by signal, and the sleep trigger module is used to send a sleep trigger signal to the fault detection module when the sunlight intensity is lower than a set threshold;

[0020] The fault detection module enters a sleep state after receiving the sleep trigger signal.

[0021] Furthermore, the sleep trigger module includes a phototransistor.

[0022] Furthermore, the voltage signal acquisition module includes a voltage dividing unit and a proportional voltage reducing unit;

[0023] The voltage dividing unit is used to divide the voltage signal of the positive electrode of the solar cell and input the voltage signal into the proportional voltage reducing unit for voltage reducing processing;

[0024] The output of the proportional voltage reduction unit is connected to the fault detection module.

[0025] Furthermore, the fault detection module is a single chip microcomputer.

[0026] The beneficial effects of the present invention are embodied in:

[0027] The solar photovoltaic panel fault detection system of the present invention can indicate fault signals of solar photovoltaic panels with faulty solar cells. Maintenance personnel can accurately and quickly find faulty solar photovoltaic panels among a large number of solar photovoltaic panels with the naked eye and replace the faulty solar photovoltaic panels in time, thus providing a guarantee for the power generation efficiency of the photovoltaic power station.

[0028] The system can also be connected to a wireless communication module to form a wireless network of various detection systems, and the network is connected to the monitoring system. The detected fault information is aggregated in the monitoring system, and the staff can quickly find the solar photovoltaic panel with faulty solar cells.

[0029] In addition, the system can be integrated on a very small circuit board, and the circuit board can be embedded in the output wiring slot of the solar photovoltaic panel. It has low cost, strong practicality, and is suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0031] Figure 1 A schematic diagram of solar cell connection in a solar photovoltaic panel comprising three groups of solar cells connected in series provided by an embodiment of the present invention;

[0032] Figure 2 A structural block diagram of a solar photovoltaic panel fault detection system provided by an embodiment of the present invention;

[0033] Figure 3 This is a circuit diagram of a solar photovoltaic panel fault detection system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0035] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the invention belongs.

[0036] A solar photovoltaic panel consists of n groups of solar cells connected in series, n ≥ 2, n is a positive integer. Since n groups of solar cells are arranged in series in the solar photovoltaic panel, the voltage of each group of solar cells is equal, so after the battery groups are connected in series, the voltage of each group of solar cells increases by 2 times the voltage of the first group of cells. For example, Figure 1 As shown, taking a solar photovoltaic panel containing three groups of solar cells connected in series as an example, the first group of solar cells is 12V, the second group of solar cells is 24V, and the third group of solar cells is 36V. Even in the case of insufficient sunlight, the voltage between solar cells is still multiplied. The connection schematic diagram of the solar cells in each solar panel is as follows Figure 1 When one or more solar cell groups fail, the voltage between the groups may appear as shown in Table 1.

[0037] Table 1 Comparison table of solar cell faults and test voltages

[0038]

[0039] It can be found from Table 1 that when any one or two groups of solar cells are faulty and isolated by diodes, the voltages at the three solar cell voltage test points will show the conditions shown in Table 1. Therefore, by analyzing the voltage signal of the positive electrode of each group of solar cells, it can be determined whether each group of solar cells in the solar photovoltaic panel is faulty.

[0040] Based on the above principle analysis, Figure 2 As shown, an embodiment of the present invention provides a solar photovoltaic panel fault detection system, which includes a voltage signal acquisition module, a fault detection module, a battery group fault indication module and a power circuit module. The voltage signal acquisition module is used to collect voltage signals of the positive poles of n groups of solar cells, and process the voltage signals of the positive poles of n groups of solar cells and send them to the fault detection module. The fault detection module is used to determine whether at least one group of faulty solar cells appears in the n-1 groups of solar cells according to the processed voltage signals of the positive poles of n groups of solar cells.

[0041] The power circuit module is connected in parallel with the positive electrodes of n groups of solar cells, and is used to step down the voltage output by the solar cells to supply power to the fault detection module and the battery group fault indication module.

[0042] The battery group fault indication module is used to send a first indication signal when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

[0043] It is understandable that among the n groups of solar cells constituting a solar photovoltaic panel, the solar cells that fail may be group 0, group 1, group 2, ..., group n. Since the fault detection module and the battery group fault indication module need to be powered by solar cells, if all n groups of solar cells fail, the fault detection module and the battery group fault indication module lose power and will not continue to work. Therefore, for the fault detection module and the battery group fault indication module of the present application to work properly, at least one group of solar cells must be in a normal state. If all n groups of solar cells fail, the system will send a corresponding indication signal through the power status indication module.

[0044] In this embodiment, n=3 is taken as an example for specific description. The specific circuit diagram is as follows: Figure 3 shown.

[0045] In this embodiment, the fault detection module is a single chip microcomputer, and its model is STM32F030. Since the voltage of the solar cell is usually 12V, which is higher than the voltage tolerance of the IO port of the single chip microcomputer, the voltage signal acquisition module needs to convert the collected voltage signal first, and then send the processed voltage signal to the fault detection module for judgment processing.

[0046] Specifically, the voltage signal acquisition module includes a voltage dividing unit and a proportional voltage reduction unit. The voltage dividing unit is used to divide the voltage signal of the positive electrode of the solar cell and then input it into the proportional voltage reduction unit for voltage reduction processing. The output of the proportional voltage reduction unit is connected to the fault detection module.

[0047] like Figure 3 As shown, in this embodiment, the proportional step-down unit uses rail-to-rail operational amplifiers U2 and U3 to convert the voltage, and the models of the operational amplifiers U2 and U3 are LM358.

[0048] Furthermore, the system further comprises a wireless communication module. The wireless communication module is used to send corresponding fault status information to the monitoring system when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

[0049] In this embodiment, the wireless communication module includes a Lora module. The single-chip microcomputer has an SPI port, which can be connected to the Lora module. A solar photovoltaic panel fault detection system is provided in each solar photovoltaic panel. Each solar photovoltaic panel fault detection system can be networked through its own Lora module and connected to the monitoring system through the Lora module. The detected fault information is gathered in the monitoring system, and the staff can quickly find the solar photovoltaic panel with faulty solar cells.

[0050] In this embodiment, Figure 3As shown, the battery pack fault indication module includes a first light emitting diode D5. The positive electrode of the first light emitting diode D5 is connected to the power circuit module, and the negative electrode is connected to the single chip microcomputer port. When the single chip microcomputer detects that there is a solar cell fault, the port connected to the first light emitting diode D5 outputs a low potential, and the first light emitting diode D5 is turned on to emit light, and the first light emitting diode D5 is used to indicate that one or two faulty solar cells appear in the solar photovoltaic panel.

[0051] In this embodiment, Figure 3 As shown, considering that the voltage of the three groups of solar cells connected in series exceeds the operating voltage of the single-chip microcomputer, the power circuit module includes a DC / DC step-down circuit, model TD1466, which outputs 5V DC current, and then transforms and stabilizes the 5V DC current through a linear regulator to output 3.3V DC current for powering the single-chip microcomputer. With the power circuit module of this application, when any one or two of the three groups of solar cells fail, the power circuit module can still supply power normally, and will not affect the normal operation of the entire solar photovoltaic panel fault detection system.

[0052] Furthermore, the system further comprises a power status indication module. The power status indication module is used to send a second indication signal when at least one group of solar cells is normal, and send a third indication signal when all solar cells are faulty.

[0053] like Figure 3 As shown, in this embodiment, the power state indication module includes a second light emitting diode D6. Figure 3 In the example, when all three solar cells fail, the second light-emitting diode D6 will not light up due to the lack of power, so the management personnel can judge that all three solar cells fail based on the fact that the second light-emitting diode D6 does not light up. When all three solar cells fail, the entire solar photovoltaic panel fault detection system has no power supply, and the entire solar photovoltaic panel fault detection system will not work.

[0054] When at least one of the three solar cells is normal, the second light emitting diode D6 is powered normally and can emit light, indicating that at least one of the cells is not faulty. At this time, the solar photovoltaic panel fault detection system is powered normally and can work normally.

[0055] Furthermore, the system further comprises a sleep trigger module. The sleep trigger module is connected to the fault detection module by signal, and is used to send a sleep trigger signal to the fault detection module when the sunlight intensity is lower than a set threshold. The fault detection module enters a sleep state after receiving the sleep trigger signal.

[0056] like Figure 3As shown, in this embodiment, the sleep trigger module includes a phototransistor Q1. The phototransistor Q1 is connected between the second in-phase input terminal of the operational amplifier U3 and ground, and the second in-phase input terminal of the operational amplifier U3 is connected to the +5V power supply in the power circuit module.

[0057] When the light intensity at night is less than the preset light threshold, the phototransistor Q1 is disconnected. At this time, the voltage of the second in-phase input terminal of the operational amplifier U3 is +5V. At this time, the second output terminal of the operational amplifier U3 outputs a high level to the microcontroller, triggering the microcontroller to enter a sleep state and not work at night.

[0058] When there is sufficient sunlight during the day, the phototransistor Q1 is turned on, and the second in-phase input terminal of the operational amplifier U3 is grounded. At this time, the second output terminal of the operational amplifier U3 outputs a low level to the microcontroller, triggering the microcontroller to enter the working state.

[0059] Finally, the solar photovoltaic panel fault detection system of the present application can be integrated on a small circuit board, the circuit board is embedded in the output wiring slot of the solar photovoltaic panel, and the light-emitting diode is led out by cables or other means so that it can be observed by the naked eye. The parts used in the system are all conventional parts that can be purchased on the market, with low cost and strong practicality, and suitable for large-scale promotion and use.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A solar photovoltaic panel fault detection system, characterized in that: It includes a voltage signal acquisition module, a fault detection module, a battery pack fault indication module and a power circuit module; wherein, The voltage signal acquisition module is used to collect voltage signals of the positive electrodes of n groups of solar cells, and process the voltage signals of the positive electrodes of n groups of solar cells and send them to the fault detection module, where n≥2, and n is a positive integer; The fault detection module is used to determine whether at least one group of faulty solar cells exists in the n-1 groups of solar cells according to the processed voltage signals of the positive electrodes of the n groups of solar cells; The power circuit module is connected in parallel with the positive electrodes of the n groups of solar cells, and is used to step down the voltage output by the solar cells and then supply power to the fault detection module and the battery group fault indication module; The battery group fault indication module is used to send a first indication signal when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

2. A solar photovoltaic panel fault detection system as claimed in claim 1, characterized in that: The system also includes a wireless communication module; The wireless communication module is used to send corresponding fault status information to the monitoring system when the fault detection module determines that at least one group of faulty solar cells exists in the n-1 groups of solar cells.

3. A solar photovoltaic panel fault detection system as claimed in claim 2, characterized in that: The wireless communication module includes a Lora module.

4. A solar photovoltaic panel fault detection system as claimed in claim 1, characterized in that: The battery pack fault indication module includes a first light emitting diode.

5. A solar photovoltaic panel fault detection system as claimed in claim 1, characterized in that: The system also includes a power status indication module; The power status indication module is used to send out a second indication signal when at least one group of solar cells is normal, and to send out a third indication signal when all n groups of solar cells are faulty.

6. A solar photovoltaic panel fault detection system as claimed in claim 5, characterized in that: The power state indication module includes a second light emitting diode.

7. A solar photovoltaic panel fault detection system as claimed in claim 1, characterized in that: The system also includes a sleep trigger module; The sleep trigger module is connected to the fault detection module by signal, and the sleep trigger module is used to send a sleep trigger signal to the fault detection module when the sunlight intensity is lower than a set threshold; The fault detection module enters a sleep state after receiving the sleep trigger signal.

8. A solar photovoltaic panel fault detection system as claimed in claim 7, characterized in that: The sleep trigger module includes a phototransistor.

9. A solar photovoltaic panel fault detection system as claimed in claim 1, characterized in that: The voltage signal acquisition module includes a voltage dividing unit and a proportional voltage reducing unit; The voltage dividing unit is used to divide the voltage signal of the positive electrode of the solar cell and input the voltage signal into the proportional voltage reducing unit for voltage reducing processing; The output of the proportional voltage reduction unit is connected to the fault detection module.

10. A solar photovoltaic panel fault detection system according to any one of claims 1 to 9, characterized in that: The fault detection module is a single chip microcomputer.

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