Photovoltaic array data acquisition device

Abstract

The utility model relates to the technical field of photovoltaic equipment, in particular to a photovoltaic array data acquisition device, which comprises a photovoltaic array composed of a plurality of photovoltaic assemblies, an environment signal acquisition module, a voltage and current acquisition isolation module, an upper computer module and a variable resistance module, and the positive electrode and the negative electrode of the photovoltaic array are respectively connected with the positive electrode and the negative electrode of the variable resistance module. The voltage and current acquisition and isolation module is connected in parallel with the photovoltaic array; the output end of the environment signal acquisition module is connected with the upper computer module, and the output end of the voltage and current acquisition isolation module is connected with the upper computer module. According to the device, photovoltaic array environment signals and electrical signals can be collected in real time, and the sampling frequency and the resolution ratio can be flexibly adjusted; the system has a good data acquisition effect, the acquisition process is rapid and safe, the operation and maintenance cost of the photovoltaic array is reduced, and the operation and maintenance efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic equipment, in particular to a photovoltaic array data acquisition device. Background Art

[0002] With the continuous growth of global energy demand and the increasing attention to environmental protection, solar photovoltaic power generation, as a clean and renewable energy source, has been rapidly developed and widely used in my country. As the core part of the photovoltaic power generation system, the performance of the photovoltaic array directly affects the power generation efficiency of the entire system. In order to improve the operational stability and power generation efficiency of the photovoltaic power generation system, it is particularly important to collect the data generated by the photovoltaic array in real time and accurately. Among them, the IV characteristics (current-voltage characteristics) of the photovoltaic array are key parameters for evaluating its performance and efficiency. IV data detection mainly involves measuring the current and voltage of the photovoltaic array under different irradiance and temperature conditions to obtain important parameters such as its maximum power point, fill factor, short-circuit current and open-circuit voltage.

[0003] Traditional IV curve scanning methods require a long time to complete a full test, making them unsuitable for rapid diagnosis and monitoring of large-scale photovoltaic arrays. Existing testing equipment can be affected by significant environmental fluctuations, resulting in inaccurate data. Furthermore, a certain degree of isolation exists between environmental signal acquisition and voltage and current data collection, hindering unified data processing and analysis. Furthermore, high-end IV test equipment is expensive, increasing the operational and maintenance costs of photovoltaic power generation systems. Some testing equipment is bulky, making it inconvenient for on-site testing in outdoor photovoltaic power plants. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a photovoltaic array data acquisition device.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A photovoltaic array data acquisition device includes a photovoltaic array 1 composed of multiple photovoltaic modules, an environmental signal acquisition module 2, a voltage and current acquisition isolation module 3, a host computer module 4 and a variable resistor module 5;

[0007] The environmental signal acquisition module 2 is used to collect real-time data of irradiance and temperature of the photovoltaic power station, convert the analog quantity into 4-20mA and connect it to the data acquisition card;

[0008] The voltage and current acquisition isolation module 3 is used to collect the real-time output voltage and current of the photovoltaic array, and convert the output voltage and current analog quantities into 4-20mA and connect them to the data acquisition card;

[0009] The host computer module 4 is used to collect each analog signal and upload it to the PC for analysis;

[0010] The variable resistor module 5 is used to change the resistance value of the two sides of the photovoltaic array, so as to obtain the output voltage and current of the photovoltaic array under different resistance values;

[0011] The positive and negative electrodes of the photovoltaic array 1 are respectively connected to the positive and negative electrodes of the variable resistor module 5, and the voltage and current acquisition isolation module 3 is connected in parallel with the photovoltaic array 1;

[0012] The output end of the environmental signal acquisition module 2 is connected to the host computer module 4 , and the output end of the voltage and current acquisition isolation module 3 is connected to the host computer module 4 .

[0013] Furthermore, the environmental signal acquisition module 2 includes a solar radiation sensor and a thermal resistor temperature probe. Preferably, the solar radiation sensor has a range of 0-2000W / m 2 , resolution is 1W / m 2 The temperature measurement range of the adhesive thermal resistor is -50℃-150℃.

[0014] The range of the global solar radiation sensor of the environmental signal acquisition module is 0-2000W / m 2 , meeting the requirements of daily irradiance collection in most areas; the resolution is 1W / m 2 , meeting the accuracy requirements of environmental signal acquisition; the temperature measurement range of the adhesive thermal resistor is -50℃-150℃, which meets the test requirements of the photovoltaic power generation system under normal circumstances.

[0015] Furthermore, the voltage and current acquisition isolation module 3 adopts a voltage and current transmitter with a rated voltage of DC0-1000V, a rated current of DC0-100A, a rated output of DC4-20mA, a response time of less than 200ms, and an accuracy of 0.2%.

[0016] Because the voltage and current output of a photovoltaic array are determined not only by environmental factors but also by the load connected to the system, isolated voltage and current transmitters are used as electrical data acquisition components to isolate the photovoltaic array from data acquisition systems such as microcontrollers and prevent damage to vulnerable electrical components caused by excessive voltage and current. The isolation module utilizes a specialized ASIC integrated circuit, significantly reducing the number of components and improving circuit reliability and long-term stability. With a response time of less than 200ms, it enables real-time current monitoring and conversion.

[0017] Furthermore, the host computer module 4 adopts an 8-channel standard analog input acquisition module, an input range of 4-20mA, an AD sampling rate of 1MHz, a Modbus communication update speed of 10Hz, and a data acquisition card with a communication interface RS485.

[0018] Furthermore, the variable resistor module 5 adopts an electronic load tester with a continuous scanning test function.

[0019] To obtain IV data from the PV array, the variable resistor module uses an electronic load tester. This electronic load tester provides a sweep test function, which can be used to test the output continuity of the power supply within a certain range. The sweep test allows for customizable parameters such as the sweep start and end points, step size, step delay, threshold type, and comparison type, making it easy to capture the output characteristics of the PV system under different loads. Furthermore, the sweep test can generate the IV characteristic curve of the PV system. Generally, to obtain important characteristic parameters such as the open-circuit voltage and short-circuit current of the PV array, the constant voltage mode is selected, with the starting point set to 0V and the end point set to exceed the rated open-circuit voltage of the PV array. To obtain more accurate IV data from the PV array, the step size should be minimized. To minimize the impact of environmental factors on the data, the step delay should be kept as short as possible, minimizing the cycle time for acquiring IV data from the PV array. Furthermore, the electronic load tester supports a constant resistance mode, which can be used to obtain the output characteristics of the PV array at a fixed operating point, allowing for investigation of the impact of environmental factors on its power generation characteristics.

[0020] Compared with the existing technology, the photovoltaic array data acquisition device of the present invention has the following beneficial effects:

[0021] This device can collect environmental signals and electrical signals of photovoltaic arrays in real time, and can flexibly adjust the sampling frequency and resolution; it has good data collection effect, the collection process is fast and safe, and it reduces the operation and maintenance costs of photovoltaic arrays and improves the operation and maintenance efficiency.

[0022] The entire system connection process of the data acquisition device of this utility model needs to be arranged rationally to prevent mutual interference between the various electrical components. In order to ensure that the signals collected by each physical quantity are consistent in time step, the environmental signal and the electrical signal are converted into 4-20mA analog current signals and sent to the data acquisition card. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the connection structure of the photovoltaic array data acquisition device of the present utility model.

[0024] In the figure, 1-photovoltaic array; 2-environmental signal acquisition module; 3-voltage and current acquisition isolation module; 4-host computer module; 5-variable resistor module. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to illustrate the present invention but are not used to limit the scope of the present invention.

[0026] In the description of the present invention, it should be understood that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, the utility model proposes a photovoltaic array data acquisition device, including a photovoltaic array 1 composed of multiple photovoltaic components, and also including an environmental signal acquisition module 2, a voltage and current acquisition isolation module 3, a host computer module 4 and a variable resistor module 5. The positive and negative poles of the photovoltaic array 1 are respectively connected to the positive and negative poles of the variable resistor module 5, and the voltage and current acquisition isolation module 3 is connected in parallel with the photovoltaic array 1; the output end of the environmental signal acquisition module 2 is connected to the host computer module 4, and the output end of the voltage and current acquisition isolation module 3 is connected to the host computer module 4.

[0029] The entire system connection process of the data acquisition device of this utility model needs to be arranged rationally to prevent mutual interference between the various electrical components. In order to ensure that the signals collected by each physical quantity are consistent in time step, the environmental signal and the electrical signal are converted into 4-20mA analog current signals and sent to the data acquisition card.

[0030] The environmental signal acquisition module 2 includes a solar radiation sensor and a thermal resistor temperature probe. Preferably, the solar radiation sensor has a range of 0-2000W / m 2 , meeting the requirements of daily irradiance collection in most areas; the resolution is 1W / m 2 , meeting the accuracy requirements for environmental signal acquisition; the adhesive thermal resistor has a temperature measurement range of -50°C to 150°C, meeting the testing requirements for normal photovoltaic power generation systems. Environmental signal acquisition module 2 is used to collect real-time irradiance and temperature data from the photovoltaic power station, converting the analog value into 4-20mA and connecting it to the data acquisition card.

[0031] The voltage and current acquisition isolation module 3 utilizes a voltage and current transmitter with a rated voltage of 0-1000V DC, a rated current of 0-100A DC, a rated output of 4-20mA DC, a response time of less than 200ms, and an accuracy of 0.2%. This module is used to collect the real-time output voltage and current of the photovoltaic array, converting the output voltage and current analog values ​​into 4-20mA and connecting them to a data acquisition card. The data acquisition card features input polarity protection, an input impedance of 20MΩ (voltage) and 250Ω (current), single-ended input, and 12-bit resolution, achieving an accuracy better than ±0.1% (one thousandth). With an AD sampling rate of up to 1MHz and 8-channel simultaneous sampling, it can meet the requirements for collecting photovoltaic array data in a short period of time.

[0032] The host computer module 4 uses an 8-channel standard analog input acquisition module, an input range of 4-20mA, an AD sampling rate of 1MHz, a Modbus communication update rate of 10Hz, and a data acquisition card with an RS485 communication interface. The host computer module 4 is used to collect each 4-20mA analog signal and upload it to the PC for analysis via RS485 line transmission;

[0033] The variable resistor module 5 adopts an electronic load tester with a continuous scanning test function. The variable resistor module 5 is used to change the resistance value of the two sides of the photovoltaic array, thereby obtaining the output voltage and current of the photovoltaic array under different resistance values.

[0034] Because the voltage and current output of a photovoltaic array are determined not only by environmental factors but also by the load connected to the system, isolated voltage and current transmitters are used as electrical data acquisition components to isolate the photovoltaic array from data acquisition systems such as microcontrollers and prevent damage to vulnerable electrical components caused by excessive voltage and current. The isolation module utilizes a specialized ASIC integrated circuit, significantly reducing the number of components and improving circuit reliability and long-term stability. With a response time of less than 200ms, it enables real-time current monitoring and conversion.

[0035] This utility model uses a resistor divider to connect the voltage and current acquisition isolation module to the photovoltaic array. One side is connected to the positive and negative terminals of the photovoltaic array, and the other side is connected to the host computer module after circuit isolation processing. The environmental signal acquisition module is directly connected to the host computer module. After the photovoltaic array is connected to the power grid through the convergence and inversion device, the electrical energy is transmitted to the compressed air energy storage system. Using this device, it is possible to collect data generated by the photovoltaic array online, including DC voltage, DC current, irradiance, and temperature, which can avoid the impact of other electrical equipment on photovoltaic power generation data. The test results are accurate and immediate. This is of great significance for process monitoring, fault diagnosis, and predictive maintenance of photovoltaic power generation systems and compressed air energy storage systems.

[0036] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A photovoltaic array data acquisition device, comprising a photovoltaic array (1) composed of a plurality of photovoltaic modules, characterized in that: It also includes an environmental signal acquisition module (2), a voltage and current acquisition isolation module (3), a host computer module (4) and a variable resistor module (5); The environmental signal acquisition module (2) is used to collect real-time data of irradiance and temperature of the photovoltaic power station, convert the analog quantity into 4-20mA and connect it to the data acquisition card; The voltage and current acquisition isolation module (3) is used for real-time output voltage and current acquisition of the photovoltaic array, converting the output voltage and current analog quantities into 4-20 mA and connecting them to a data acquisition card; The host computer module (4) is used to collect each analog signal and upload it to the PC for analysis; The variable resistor module (5) is used to change the resistance value connected to both sides of the photovoltaic array, thereby obtaining the output voltage and current of the photovoltaic array under different resistance values; The positive and negative electrodes of the photovoltaic array (1) are respectively connected to the positive and negative electrodes of the variable resistor module (5), and the voltage and current acquisition isolation module (3) is connected in parallel with the photovoltaic array (1); The output end of the environmental signal acquisition module (2) is connected to the host computer module (4), and the output end of the voltage and current acquisition isolation module (3) is connected to the host computer module (4).

2. A photovoltaic array data acquisition device according to claim 1, characterized in that: The voltage and current acquisition isolation module (3) adopts a voltage and current transmitter with a rated voltage of DC0-1000V, a rated current of DC0-100A, a rated output of DC4-20mA, a response time of less than 200ms, and an accuracy of 0.2%.

3. The photovoltaic array data acquisition device according to claim 1, characterized in that: The host computer module (4) adopts an 8-channel standard analog input acquisition module, an input range of 4-20mA, an AD sampling rate of 1MHz, a Modbus communication update speed of 10Hz, and a data acquisition card with a communication interface RS485.

4. The photovoltaic array data acquisition device according to claim 1, characterized in that: The variable resistor module (5) adopts an electronic load tester with a continuous scanning test function.

Images