Voltage monitoring device for solar photovoltaic panel string

Abstract

The utility model belongs to the field of voltage monitoring, particularly relates to a voltage monitoring device for a solar photovoltaic panel group string, and aims to solve the problems in the prior art that the number of devices is large, wiring and device maintenance are complex and the cost is high because electronic monitoring devices with the same number are required to be provided according to the number of photovoltaic panels. The device is applied to a plurality of photovoltaic panels connected in series, the anode and the cathode of each photovoltaic panel are respectively connected with the input end of a relay, the output end of each relay connected with the anode and the cathode of the photovoltaic panel is connected with the same voltage dividing unit, and the voltage dividing unit is used for reducing the voltage difference between the two ends of the photovoltaic panel. The voltage dividing unit is connected with the data reading unit, and the data reading unit is used for reading the voltage values of the positive electrode and the negative electrode of the photovoltaic panel. According to the utility model, the number and difficulty of wiring are reduced, the overall electrical wiring layout is simplified, and the installation time and cost caused by a large amount of wiring are reduced.

Description

Technical Field

[0001] The utility model belongs to the field of voltage monitoring, and in particular relates to a voltage monitoring device for a solar photovoltaic panel string. Background Art

[0002] During the operation of photovoltaic power stations, the output power of individual components has seriously dropped due to factors such as foreign objects, bird droppings, and sunlight blocking. Since photovoltaic panels are connected in series and parallel to form a square array, the output power drop of individual components will be amplified, causing the power generation of the entire square array to drop, even to less than half of the nominal power. Maintenance personnel cannot determine which position of the component output power has dropped seriously through monitoring or naked eyes, so maintenance personnel need to arrive at the site and test the output power of each component. Operation and maintenance is time-consuming and labor-intensive, and the cost is very high, and full-time electrical engineers must be hired for operation and maintenance.

[0003] In order to monitor the operating status of each photovoltaic panel in the photovoltaic panel array in real time, the existing technology develops electronic monitoring equipment with communication functions to remotely monitor the instantaneous voltage of each photovoltaic panel, and can locate photovoltaic panels with severe output voltage drops. However, for the case of photovoltaic panels connected in series, that is, multiple photovoltaic panels are connected in sequence to form a photovoltaic panel string, the positive and negative poles of each panel are connected, and the voltage is superimposed step by step, which increases the voltage of the system. In this way, although the voltage at both ends of each photovoltaic panel is tens of volts, since each group of photovoltaic panels in series has a potential connection between the positive and negative poles, only one end of the first photovoltaic panel is grounded, and the voltage of the first photovoltaic panel to the ground is tens of volts, but the absolute voltage of other photovoltaic panels to the ground is successively increased step by step, and the voltage of the entire group is very high, reaching more than hundreds of volts.

[0004] The existing technology monitors the voltage of each group of solar photovoltaic panels connected in series, and then infers the overall status of a group of photovoltaic panel components based on a certain algorithm. In order to measure the voltage at both ends of each photovoltaic panel with high precision, the existing technology requires an electronic monitoring device for each photovoltaic panel, and then uploads the monitored voltage data through the communication function. Each electronic monitoring device is independent in terms of electricity, which reduces the impact of the photovoltaic panels connected in series on the potential connection. However, the disadvantage of this technology is that it requires the same number of electronic monitoring devices to be provided for the number of photovoltaic panels, which results in a large number of devices, complex wiring and equipment maintenance, and high costs.

[0005] Based on this, the utility model proposes a voltage monitoring device for a solar photovoltaic panel string. Utility Model Content

[0006] In order to solve the above-mentioned problem in the prior art, that is, the prior art needs to provide an equal amount of electronic monitoring equipment corresponding to the number of photovoltaic panels, which results in a huge number of equipment, complicated wiring and equipment maintenance, and high cost. The utility model provides a voltage monitoring device for a solar photovoltaic panel string, which is applied to a plurality of photovoltaic panels connected in series, wherein the positive and negative poles of each photovoltaic panel are respectively connected to the input end of a relay, and the output end of each relay connected to the positive and negative poles of the photovoltaic panel is connected to the same voltage divider unit, and the voltage divider unit is used to reduce the voltage difference between the two ends of the photovoltaic panel, and the voltage divider unit is connected to a data reading unit, and the data reading unit is used to read the voltage values ​​of the positive and negative poles of the photovoltaic panel.

[0007] In some preferred embodiments, the voltage dividing unit includes a first resistor, a second resistor, a third resistor and a fourth resistor;

[0008] The output end of the relay corresponding to the positive pole of the photovoltaic panel is connected to the first end of the first resistor, and the output end of the relay corresponding to the negative pole of the photovoltaic panel is connected to the first end of the second resistor;

[0009] The third resistor and the fourth resistor are connected between the second end of the first resistor and the second end of the second resistor, and the third resistor and the fourth resistor are grounded.

[0010] In some preferred embodiments, the data reading unit includes an analog-to-digital converter;

[0011] The second end of the first resistor and the second end of the second resistor are respectively connected to the analog-to-digital converter;

[0012] The analog-to-digital converter is used to collect the voltages of the positive and negative electrodes of the photovoltaic panel after voltage division.

[0013] In some preferred embodiments, the control end of each relay is connected to a relay conduction selection controller, and the relay conduction selection controller controls only two relays corresponding to the positive and negative poles of a photovoltaic panel to conduct at each moment based on a timing sequence.

[0014] In some preferred implementations, the analog-to-digital converter is connected to a central processing unit, and the central processing unit is used to convert the collected divided voltage into voltage data.

[0015] In some preferred embodiments, the central processor is connected to a communication unit, and the communication unit is used to output the voltage data to a terminal for storage and analysis.

[0016] In some preferred embodiments, among a plurality of photovoltaic panels connected in series, the first photovoltaic panel is connected to the power output terminal, and the last photovoltaic panel is connected to the ground line.

[0017] In some preferred embodiments, the number of the voltage dividing units is consistent with the number of the photovoltaic panels.

[0018] In some preferred embodiments, the number of the relays is twice the number of the photovoltaic panels.

[0019] Beneficial effects of the utility model:

[0020] (1) The voltage divider composed of high-precision resistors is used to effectively reduce the large voltage difference generated by the photovoltaic panel to a safe range suitable for measurement by the analog-to-digital converter, which not only ensures the safety of the equipment, but also ensures that the voltage signal is collected without distortion.

[0021] (2) By configuring multiple relays and using a relay conduction selection controller, independent monitoring of each photovoltaic panel in series is achieved, which can accurately capture the voltage condition of each photovoltaic panel in the working state without causing mutual interference due to the simultaneous connection of multiple panels, thereby improving the accuracy of data analysis and the refinement of fault location.

[0022] (3) The voltage signal processed by the voltage divider unit is converted into a digital signal through an analog-to-digital converter, which is convenient for the central processing unit to perform further data processing and storage. It can also be transmitted to an external computer or other monitoring platform in real time through the communication unit, facilitating remote monitoring and data analysis, and providing strong data support for optimizing energy management, fault warning and performance evaluation.

[0023] (4) The central processor cooperates with the time series control mechanism of the relay to read the voltage of only one photovoltaic panel at the same time, thereby realizing a fast, continuous and conflict-free data acquisition process, greatly improving the monitoring efficiency of the system.

[0024] (5) The present application controls the access sequence of each photovoltaic panel through relays to achieve independent monitoring of each panel in the series-connected photovoltaic panel string, avoiding the complexity of laying out monitoring lines for all photovoltaic panels in parallel under the traditional method, reducing the amount and difficulty of wiring, thereby simplifying the overall electrical wiring layout and reducing the installation time and cost caused by a large amount of wiring.

[0025] (6) The voltage of each photovoltaic panel is processed by the same voltage divider unit and analog-to-digital converter, which realizes the sharing of hardware resources. Compared with equipping each photovoltaic panel with an independent measurement device, it greatly reduces the equipment cost and subsequent maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 The utility model is a schematic diagram of the structural connection of a voltage monitoring device for a solar photovoltaic panel string. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] like Figure 1 As shown, the utility model provides a voltage monitoring device for a solar photovoltaic panel string, which is applied to multiple photovoltaic panels 1 connected in series, wherein the positive and negative poles of each photovoltaic panel 1 are respectively connected to the input end of a relay 2, and the output end of each relay 2 connected to the positive and negative poles of the photovoltaic panel 1 is connected to the same voltage dividing unit 3, and the voltage dividing unit 3 is used to reduce the voltage difference between the two ends of the photovoltaic panel 1, and the voltage dividing unit 3 is connected to a data reading unit, and the data reading unit is used to read the voltage values ​​of the positive and negative poles of the photovoltaic panel 1.

[0031] For further explanation of the present utility model, the voltage dividing unit 3 includes a first resistor 31, a second resistor 32, a third resistor 33 and a fourth resistor 34;

[0032] The output end of the relay 2 corresponding to the positive pole of the photovoltaic panel 1 is connected to the first end of the first resistor 31, and the output end of the relay 2 corresponding to the negative pole of the photovoltaic panel 1 is connected to the first end of the second resistor 32;

[0033] The third resistor 33 and the fourth resistor 34 are connected between the second end of the first resistor 31 and the second end of the second resistor 32 , and the third resistor 33 and the fourth resistor 34 are grounded.

[0034] Among them, each voltage dividing unit 3 of the present application is composed of 4 high-precision resistors, which proportionally reduce the voltage difference between the two ends of the photovoltaic panel 1 into a measurable range.

[0035] For further explanation of the present invention, the control end of each relay 2 is connected to the relay conduction selection controller 4, and the relay conduction selection controller 4 controls only the two relays 2 corresponding to the positive and negative poles of a photovoltaic panel 1 to conduct at each moment based on the timing.

[0036] For further explanation of the present utility model, the data reading unit includes an analog-to-digital converter 5;

[0037] The second end of the first resistor 31 and the second end of the second resistor 32 are respectively connected to the analog-to-digital converter 5;

[0038] The analog-to-digital converter 5 is used to collect the voltages of the positive and negative electrodes of the photovoltaic panel 1 after voltage division.

[0039] For further explanation of the present invention, the analog-to-digital converter 5 is connected to the central processing unit 6, and the central processing unit 6 is used to convert the collected divided voltage into voltage data.

[0040] For further explanation of the present invention, the central processor 6 is connected to the communication unit 7, and the communication unit 7 is used to output the voltage data to the terminal for storage and analysis.

[0041] For further explanation of the present invention, among a plurality of photovoltaic panels 1 connected in series, the first photovoltaic panel 1 is connected to the power output terminal, and the last photovoltaic panel 1 is connected to the ground wire.

[0042] For further explanation of the present invention, the number of the voltage dividing units 3 is consistent with the number of the photovoltaic panels 1 .

[0043] For further explanation of the present invention, the number of the relays 2 is twice the number of the photovoltaic panels 1 .

[0044] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0046] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0047] So far, the technical solution of the utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the utility model is obviously not limited to these specific embodiments. Without departing from the principle of the utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the utility model.

Claims

1. A voltage monitoring device for a solar photovoltaic panel string, applied to a plurality of photovoltaic panels (1) connected in series, characterized in that: The positive pole and negative pole of each photovoltaic panel (1) are respectively connected to the input end of a relay (2); the output end of each relay (2) connected to the positive pole and negative pole of the photovoltaic panel (1) is connected to the same voltage divider unit (3); the voltage divider unit (3) is used to reduce the voltage difference between the two ends of the photovoltaic panel (1); the voltage divider unit (3) is connected to a data reading unit; the data reading unit is used to read the voltage values ​​of the positive pole and negative pole of the photovoltaic panel (1).

2. A voltage monitoring device for a solar photovoltaic panel string according to claim 1, characterized in that: The voltage dividing unit (3) comprises a first resistor (31), a second resistor (32), a third resistor (33) and a fourth resistor (34); The output end of the relay (2) corresponding to the positive pole of the photovoltaic panel (1) is connected to the first end of the first resistor (31), and the output end of the relay (2) corresponding to the negative pole of the photovoltaic panel (1) is connected to the first end of the second resistor (32); The third resistor (33) and the fourth resistor (34) are connected between the second end of the first resistor (31) and the second end of the second resistor (32), and the third resistor (33) and the fourth resistor (34) are grounded.

3. A voltage monitoring device for a solar photovoltaic panel string according to claim 2, characterized in that: The data reading unit comprises an analog-to-digital converter (5); The second end of the first resistor (31) and the second end of the second resistor (32) are respectively connected to the analog-to-digital converter (5); The analog-to-digital converter (5) is used to collect the voltages of the positive electrode and the negative electrode of the photovoltaic panel (1) after voltage division.

4. A voltage monitoring device for a solar photovoltaic panel string according to claim 1, characterized in that: The control end of each relay (2) is connected to a relay conduction selection controller (4), and the relay conduction selection controller (4) controls only two relays (2) corresponding to the positive and negative poles of a photovoltaic panel (1) to conduct at each moment based on a timing sequence.

5. A voltage monitoring device for a solar photovoltaic panel string according to claim 3, characterized in that: The analog-to-digital converter (5) is connected to a central processing unit (6), and the central processing unit (6) is used to convert the collected divided voltage into voltage data.

6. A voltage monitoring device for a solar photovoltaic panel string according to claim 5, characterized in that: The central processor (6) is connected to a communication unit (7), and the communication unit (7) is used to output the voltage data to a terminal for storage and analysis.

7. A voltage monitoring device for a solar photovoltaic panel string according to claim 1, characterized in that: Among the multiple photovoltaic panels (1) connected in series, the first photovoltaic panel (1) is connected to the power output terminal, and the last photovoltaic panel (1) is connected to the ground wire.

8. A voltage monitoring device for a solar photovoltaic panel string according to claim 1, characterized in that: The number of the voltage dividing units (3) is consistent with the number of the photovoltaic panels (1).

9. A voltage monitoring device for a solar photovoltaic panel string according to claim 1, characterized in that: The number of the relays (2) is twice the number of the photovoltaic panels (1).

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