CN108663088A - Intelligent photovoltaic power station distribution cloud monitors system - Google Patents

Abstract

The invention relates to a distributed cloud monitoring system for an intelligent photovoltaic power station, which includes a data collection and monitoring module, a data transmission module, and a cloud platform module. The data collection and monitoring module collects operating data between two adjacent photovoltaic modules in a photovoltaic power station and Packing the operating data to form a data packet and sending it to the cloud platform module through the data transmission module, the cloud platform module receives the data packet and parses the data packet, and displays and stores the parsed data ; Wherein, the data transmission module includes a wireless serial port server. The data acquisition and monitoring module of the present invention can monitor the operation information of two adjacent photovoltaic modules in the power station, and use the wireless serial port server to upload the data packets to the cloud for analysis; maintenance personnel can realize intelligent on-duty through the cloud platform module monitoring system , Big data analysis and fault pre-diagnosis and other functions can effectively increase the utilization rate of on-site equipment and make operation and maintenance more accurate and convenient.

Description

Distributed Cloud Monitoring System for Smart Photovoltaic Power Stations

technical field

The invention relates to a distributed cloud monitoring system for an intelligent photovoltaic power station.

Background technique

Due to the depletion of traditional energy and the improvement of power quality in today's society, solar photovoltaic power generation technology is more and more widely used. However, at present, solar photovoltaic power stations are mainly used in areas with no electricity or little electricity and some special places far away from the public grid, and the distribution of photovoltaic power stations in the same area is uneven. Therefore, how to centralize dispatch and manage these decentralized energy systems to achieve effective For the purpose of use, remote monitoring of photovoltaic power plants is becoming more and more important.

Early monitoring of photovoltaic power plant systems is generally established under short-range conditions, that is, close-range monitoring. The operating parameters and environmental parameters of various power stations are displayed on the liquid crystal, and the maintenance personnel are on site to check the values displayed by the monitoring equipment and make corresponding processing. However, with the expansion of the scale of the photovoltaic power station and the harsh natural environment in the area where the power station is located, the labor intensity of the maintenance personnel of this scheme is high, the management level is not high, and it needs a lot of manpower, material and financial resources, and with the expansion of the power station scale, It has become more and more unable to adapt to the development of modern economy. Later, with the rapid development of IT technology and communication technology, remote monitoring technology is widely used in photovoltaic power plants. Existing monitoring systems for small and medium-sized photovoltaic power plants generally use sensors combined with Bluetooth, Ethernet, radio frequency communication, etc. to form a local area network to monitor the operating parameters of photovoltaic power plants. However, for photovoltaic power plants with a large number of monitoring and a wide range, these technologies will have some problems. Bluetooth has a low communication rate, and its maximum transmission distance is 100m, which has certain security problems. It is obviously not comprehensive for large-scale photovoltaic power plants; while Ethernet needs to pass through wired media including coaxial cables, twisted-pair wires and optical fibers. For large-scale photovoltaic power station wiring, it needs to consume a lot of manpower and material resources, which obviously increases the operating cost of the photovoltaic power station. GSM wireless communication is the connection between the tracking system controller and the monitoring computer, and the monitoring computer communicates with the mobile phone through the communication module and the communication base station. The administrator of the tracking power station sends an instruction message to the GSM communication module through the mobile phone, and the monitoring software in the monitoring computer reads the message, analyzes the content of the message, and then sends the corresponding instruction to the tracking system controller through the 485 bus, and the tracking system controller receives it. Receive the instruction, execute the instruction, and give feedback to the monitoring software. After receiving the feedback, the monitoring software sends the feedback information to the administrator's mobile phone through the communication module. However, its stability is poor, its power consumption is high, and its networking capability is low, so it is not suitable for transmitting accurate and important operating parameters.

Contents of the invention

The purpose of the present invention is to provide a distributed cloud monitoring system for intelligent photovoltaic power plants that can monitor the operation information of two adjacent photovoltaic modules in the power plant, and use GPRS-DTU to stably upload data packets to the cloud for analysis.

In order to achieve the above object, the present invention provides the following technical solutions: a distributed cloud monitoring system for smart photovoltaic power plants, the distributed cloud monitoring system for smart photovoltaic power plants includes a data collection and monitoring module, a data transmission module, and a cloud platform module. The data acquisition and monitoring module collects the operating data between two adjacent photovoltaic modules in the photovoltaic power station and packs the operating data to form a data packet and sends it to the cloud platform module through the data transmission module, and the cloud platform module receives The data packet is analyzed, and the analyzed data is displayed and stored; wherein, the data transmission module includes a wireless serial port server.

Further, the wireless serial port server is GPRS-DTU.

Further, the data transmission module also includes a communication base station and an RS485 bus connected to the communication base station and the wireless serial port server.

Further, the data acquisition and monitoring module includes a power supply circuit, a light intensity and temperature measurement circuit, a differential amplifier and an analog-to-digital conversion circuit, and a microprocessor, wherein:

Power supply circuit: provide power supply for the light intensity and temperature measurement circuit and A/D conversion circuit;

Light intensity and temperature measurement circuit: monitor the solar radiation and temperature data, and simultaneously collect the voltage and current data of the photovoltaic module during operation and transmit them to the differential amplifier and analog-to-digital conversion circuit;

Differential amplifier and analog-to-digital conversion circuit: amplify and monitor the voltage and current data of the photovoltaic module and transmit it to the microprocessor;

Microprocessor: receiving voltage and current data and transmitting to the cloud platform module.

Further, the power supply circuit includes a first-stage step-down circuit, a second-stage step-down circuit, and a third-stage step-down circuit; the first-stage step-down circuit processes voltage to output a first voltage value to the The second-stage step-down circuit and the third-stage step-down circuit, the second-stage step-down circuit outputs a second voltage value to the single-chip microcomputer, and the third-stage step-down circuit outputs a third voltage value to the Differential amplifier and analog-to-digital conversion circuit.

Further, the first-stage step-down circuit adopts the LM2596 chip, and the second-stage step-down circuit and the third-stage step-down circuit use the SPX3819 chip.

Further, the first voltage value is 5.5V, the second voltage value is 3.3V, and the third voltage value is 5V.

Further, the light intensity and temperature measurement circuit includes a BH1750FVI chip for measuring light intensity and a temperature sensor DS18B20 for measuring temperature.

Further, the differential amplifier and analog-to-digital conversion circuit includes a differential amplifier circuit that uses the AD620 chip to amplify the small signal voltage, and an analog-to-digital conversion circuit that uses the MCP3421 chip to perform A/D conversion of the output signal.

Further, the microprocessor is an ATmega128A single-chip microcomputer.

The beneficial effect of the present invention is that: the data acquisition and monitoring module of the present invention can monitor the operation information of two adjacent photovoltaic modules in the power station, and use the wireless serial port server to upload the data packets to the cloud for analysis; maintenance personnel can use the cloud platform to The module monitoring system realizes functions such as intelligent on-duty monitoring, big data analysis and fault pre-diagnosis, effectively increasing the utilization rate of on-site equipment, and making operation and maintenance more accurate and convenient.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention and accompanying drawings are described in detail below.

Description of drawings

Fig. 1 is a schematic structural diagram of a distributed cloud monitoring system for a smart photovoltaic power plant according to the present invention.

FIG. 2 is a schematic diagram of the principle of the data acquisition and monitoring module in FIG. 1 .

FIG. 3 is a schematic diagram of the first-stage step-down circuit in FIG. 2 .

FIG. 4 is a schematic diagram of the second-stage and third-stage step-down circuits in FIG. 2 .

Figure 5 is a schematic diagram of the light measurement circuit.

Figure 6 is a schematic diagram of the temperature measurement circuit.

Figure 7 is a schematic diagram of the differential amplifier circuit.

Figure 8 is a schematic diagram of the A/D analog-to-digital conversion circuit.

Fig. 9 is a flow chart of the monitoring software of the data acquisition and measurement terminal.

Figure 10 is a topological diagram of measurement data flow.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Please refer to Fig. 1, the intelligent photovoltaic power plant distributed cloud monitoring system in a preferred embodiment of the present invention comprises data acquisition and monitoring module 1, data transmission module 2, cloud platform module 3, and described data acquisition and monitoring module 1 collects The operating data between two adjacent photovoltaic modules in the photovoltaic power station is packaged to form a data packet and sent to the cloud platform module 3 through the data transmission module 2, and the cloud platform module 3 receives the data package and analyze the data package, and display and store the analyzed data; wherein, the data transmission module 2 includes a wireless serial port server. In this embodiment, the wireless serial port server is GPRS-DTU.

Referring to Fig. 2, the data acquisition and monitoring module 1 includes a power supply circuit 11, a light intensity and temperature measurement circuit 12, a differential amplifier and an analog-to-digital conversion circuit 13, and a microprocessor 14, wherein:

Power supply circuit 11 : supplying power to the light intensity and temperature measurement circuit 12 , differential amplifier and analog-to-digital conversion circuit 13 , and microprocessor 14 . . The method of step-down step-down is adopted, that is, the power supply circuit 11 includes a first-stage step-down circuit, a second-stage step-down circuit and a third-stage step-down circuit; the first-stage step-down circuit processes the voltage to output the first stage A voltage value is sent to the second-stage step-down circuit and the third-stage step-down circuit, the second-stage step-down circuit outputs a second voltage value to the single-chip microcomputer, and the third-stage step-down circuit outputs the first Three voltage values are sent to the differential amplifier and analog-to-digital conversion circuit 13. In this embodiment, the first-stage step-down circuit uses an LM2596 chip, and the second-stage step-down circuit and the third-stage step-down circuit use an SPX3819 chip. The first voltage value is 5.5V, the second voltage value is 3.3V, and the third voltage value is 5V. Please refer to Figure 3, Figure 3 is a schematic diagram of the LM2596 chip step-down circuit. The chip LM2596 is powered by the photovoltaic module, input from pin 1, R1 and R2 are feedback resistors, used to adjust the output voltage, D2 Schottky protection circuit, the capacitors at both ends of the circuit are filter capacitors, to ensure the stability of the input and output voltage. 2 pins are output, the output voltage expression is: V _OUT =V _REF ×(1+R ₂ /R ₁ ); where: V _REF is the internal reference source, V _REF ＝1.23V.

Please refer to Figure 4, the schematic diagram of the SPX3819 chip 5V step-down circuit is shown in the figure. The 5V type SPX3819 chip is used as the third step-down circuit, which takes 5.5V voltage as input, and lowers the voltage to 5V to supply chip AD620 and analog-to-digital conversion chip to realize stable voltage input. In the figure, pin 1 of the SPX3819 chip is a power supply pin, which is supplied by a 5.5V voltage supply from the LM2596 step-down circuit, pin 2 is grounded, pin 3 is an enable terminal, and pin 4 is a low-dropout linear voltage regulator, which is used to reduce linear noise. The capacitor before the output is mainly used for filtering. Therefore, the distributed cloud monitoring system of the smart photovoltaic power station is powered by photovoltaic modules, and then the power circuit 11 in the data acquisition and monitoring module 1 steps down the voltage, which can be respectively supplied to the microprocessor 14 and other chips to achieve stable voltage input.

Light intensity and temperature measurement circuit 12: monitor the solar radiation and temperature data, and simultaneously collect the voltage and current data of the photovoltaic module during operation and transmit them to the differential amplifier and analog-to-digital conversion circuit 13 . Factors such as solar radiation and ambient temperature affect the operation of photovoltaic power plants, among which solar radiation is the direct factor that causes the photovoltaic cell to produce the volt effect; and temperature affects the solar energy conversion efficiency, the working efficiency of the photovoltaic panel and the It is an important parameter for issues such as service life, so the monitoring of solar radiation and temperature is essential. In this embodiment, the light intensity and temperature measurement circuit 12 includes a BH1750FVI chip for measuring light intensity and a temperature sensor DS18B20 for measuring temperature.

The system uses the BH1750FVI chip to measure the intensity of the light, direct digital output, does not distinguish between ambient light sources, and has spectral characteristics close to visual sensitivity, and can perform high-precision measurement of 1 lux for a wide range of brightness. Please refer to Figure 5. In the figure, VCC is the power supply pin, 3-5V power supply, SCL is the IIC bus clock pin, SDA is the IIC bus data pin, and A/DDR is the IIC device address pin of the BH1750FVI chip.

Temperature measurement uses the sensor DS18B20 to measure the temperature. The temperature detected in the system is divided into the ambient temperature of the power station and the temperature of the battery board. Please refer to FIG. 6 , in which Vcc is a power supply pin, 5V power supply, GND is a power supply ground, and DQ is a 1-wire bus interface to realize bidirectional communication between the microprocessor 14 and DS18B20. Among them, DS18B20_1 measures the ambient temperature around the power station, and DS18B20_2 measures the temperature of the solar panel.

By measuring the intensity of sunlight, the ambient temperature around the power station and the temperature of the solar panels, it is possible to understand the factors affecting the photovoltaic power station in real time and ensure the normal and stable operation of the photovoltaic power station.

Differential amplifier and analog-to-digital conversion circuit 13: the voltage and current data of the photovoltaic module are amplified and monitored and transmitted to the microprocessor 14; the differential amplifier and analog-to-digital conversion circuit 13 includes a differential amplifier amplifier circuit and an A /D analog-to-digital conversion circuit. In this embodiment, the differential amplifier and analog-to-digital conversion circuit includes a differential amplifier amplifier circuit that uses the AD620 chip to amplify the small signal voltage, and an analog-to-digital conversion circuit that uses the MCP3421 chip to perform A/D conversion of the output signal.

The differential amplifier circuit uses the AD620 chip, and the output voltage is sent to an AD620 differential amplifier circuit through a voltage divider circuit, followed by amplification at 1:1. The output current passes through a 0.01Ω resistor, and the voltage at both ends is sent to the A/D analog-to-digital conversion circuit for analog-to-digital conversion through another AD620 differential amplifier circuit with 10 times amplification. Please refer to Figure 7, the input voltage and ground are respectively connected to AD_IN1 and AD_IN2, which can realize high-precision differential amplification. Gain amplification is achieved by adjusting the inaG1 resistor.

The A/D analog-to-digital conversion circuit uses the MCP3421 chip to perform A/D conversion of the output signal. The voltage signal obtained by the differential amplifying circuit is converted into digital and analog by the A/D conversion circuit, which is convenient for accurate measurement of two voltages. Please refer to FIG. 8 , the output voltage of the differential amplifier circuit passes through pin 1 of the MCP3421 chip, which can realize A/D conversion and output to the microprocessor 14 through the SCL and SDA ports, and measure the tiny voltage. In this embodiment, the communication protocol adopted by the A/D analog-to-digital conversion circuit is the IIC protocol.

Through the differential amplifier and analog-to-digital conversion circuit, the voltage and current of the photovoltaic module can be accurately measured to realize the measurement of the operating parameters of the photovoltaic module, so as to ensure the stable output and normal operation of the photovoltaic power station.

Microprocessor 14: receiving voltage and current data and transmitting to the cloud platform module 3. In this embodiment, the microprocessor 14 is an ATmega128A single-chip microcomputer.

The above is the hardware design and data collection process of the data collection and monitoring module 1, and the data monitoring is shown in FIG. 9 . When the distributed photovoltaic power station monitoring terminal is working, it needs to perform control operations such as system initialization, data acquisition, analog-to-digital conversion, and D/A output. Microprocessor 14ATmega128A initializes registers such as D/A chip, A/D conversion register, timer 0 interrupt register. On the one hand, the two voltages collected are converted into digital signals that can be directly processed by the microprocessor 14ATmega128A through the A/D conversion function in the A/D conversion register. On the other hand, the light intensity and temperature sensor communicates with the AVR through IIC to read out the current light intensity and temperature of the environment. The last two voltages, temperature and light intensity are properly converted into the D/A function, and the corresponding voltage is output, and then the data transmission module 2 transparently transmits the data to the cloud platform module 3 .

The data transmission module 2 also includes a communication base station and an RS485 bus connected to the communication base station and GPRS-DTU. After the operating parameters and environmental parameters of the photovoltaic power plant are collected by the data collection and monitoring module 1, they are then transparently transmitted to the cloud platform module 3 by the GPRS-DTU through the RS485 bus. GPRS-DTU can realize the mutual transmission of data between the serial device and the network server through the GPRS network.

First configure the address and port of the cloud platform module 3, the address is cloudata.usr.cn or the address of a certain server, the port is 15000, using the TCP data protocol, and then write the device number and communication password of the transparent transmission cloud into the device After configuring the parameters of the data transmission module 2, the collected data is transmitted to the cloud server according to the corresponding protocol. The measurement data flow topology diagram is shown in Figure 10. Connect the A/D module Modbus RTU with the RS485 serial port of GPRS-DTU. After the data collected by RTU is packaged through the GPRS-DTU serial port, the data is organized through Socket A to conform to the complex TCP/IP protocol family, and then transported via TCP/IP The layer reaches the GPRS network layer of the corresponding address.

The default equipment added by the cloud platform module 3 is mainly corresponding DTU and serial port server. After the addition is completed, the system automatically distributes the ID, and writes in the equipment by software to complete the access. Then select the communication protocol Modbus, and the cloud server will analyze it according to the set protocol format, and store it in the database according to the setting of the data point, process the alarm, and push it to the front end. After adding the device, use the USB to RS485 adapter, connect A and B on the adapter to the A and B interfaces of GPRS-DTU respectively, and plug the other end into the USB of the computer to complete the setting of the GPRS transmission module.

When the LINKA light is on, it means that the data transmission module 2 is connected to the cloud platform module 3, can communicate normally, and transmits data to the cloud platform module 3. Data points will be added below to read the data of the Modbus slave registers and display them in the monitoring center. The associated device refers to the device added in the first step. The slave device id represents the Modbus slave address. When selecting the register area, it should be selected according to the register in the Modbus RTU slave where the data is located. Whether it is a holding register or an input register, the offset The quantity is the actual address of the register of the read data in the Modbus slave machine minus one. In addition, by setting a trigger, if the measured data is not within the range set by the trigger, information about abnormal data points will be sent to the user via WeChat or email, so that maintenance personnel can repair photovoltaic equipment in a timely and accurate manner.

After the cloud platform module 3 is designed, the data analyzed and transmitted by the cloud platform module 3 is displayed and stored in the monitoring center, and the user can query history and display fault information.

When testing the distributed cloud monitoring system of smart photovoltaic power plants, the operating parameters of each photovoltaic module are collected in real time. Among them, the 0x01 node is the photovoltaic module 1, and the 0x02 address node is the photovoltaic module 2. The test results are shown in Table 1 and Table 2.

Table 1

Table 2

The measurement results show that the system can realize the voltage measurement with a resolution of 0.1V and the measurement of current, ambient temperature, solar panel temperature and light intensity. At the same node at different times, the photovoltaic module works abnormally at noon. It may be due to shadows formed on the solar cell module by dust, fallen leaves and other obstructions, which causes the current and voltage of some single cells in the solar cell module to change. At the same time, the system detects that a photovoltaic module fails at different nodes at the same time. The distributed cloud monitoring system of the intelligent photovoltaic power station can realize the analysis and comparison of the measured data, and alarm the fault information of the photovoltaic power station through WeChat or email.

To sum up: the data acquisition and monitoring module 1 of the present invention can monitor the operation information of two adjacent photovoltaic modules in the power station, and use the wireless serial port server to upload the data packets to the cloud for analysis; maintenance personnel can use the cloud platform module 3 The monitoring system realizes functions such as intelligent on-duty monitoring, big data analysis, and fault pre-diagnosis, effectively increasing the utilization rate of on-site equipment, and making operation and maintenance more accurate and convenient.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A distributed cloud monitoring system for an intelligent photovoltaic power plant, characterized in that the distributed cloud monitoring system for an intelligent photovoltaic power plant comprises a data acquisition and monitoring module, a data transmission module, and a cloud platform module, and the data acquisition and monitoring module collects The operating data between two adjacent photovoltaic modules in the photovoltaic power station is packaged to form a data packet and sent to the cloud platform module through the data transmission module, and the cloud platform module receives the data packet and The data packet is analyzed, and the analyzed data is displayed and stored; wherein, the data transmission module includes a wireless serial port server. 2. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 1, wherein the wireless serial port server is a GPRS-DTU. 3. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 1, wherein the data transmission module further includes a communication base station and an RS485 bus connected to the communication base station and the wireless serial port server. 4. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 1, wherein the data acquisition and monitoring module includes a power supply circuit, a light intensity and temperature measurement circuit, a differential amplifier and an analog-to-digital conversion circuit, a microprocessing device, of which: Power supply circuit: provide power supply for the light intensity and temperature measurement circuit and A/D conversion circuit; Light intensity and temperature measurement circuit: monitor the solar radiation and temperature data, and simultaneously collect the voltage and current data of the photovoltaic module during operation and transmit them to the differential amplifier and analog-to-digital conversion circuit; Differential amplifier and analog-to-digital conversion circuit: amplify and monitor the voltage and current data of the photovoltaic module and transmit it to the microprocessor; Microprocessor: receiving voltage and current data and transmitting to the cloud platform module. 5. The distributed cloud monitoring system for intelligent photovoltaic power plants as claimed in claim 4, wherein the power supply circuit includes a first-stage step-down circuit, a second-stage step-down circuit and a third-stage step-down circuit; The first-stage step-down circuit processes the voltage to output a first voltage value to the second-stage step-down circuit and the third-stage step-down circuit, and the second-stage step-down circuit outputs a second voltage value to the In the single chip microcomputer, the third step-down circuit outputs a third voltage value to the differential amplifier and analog-to-digital conversion circuit. 6. The distributed cloud monitoring system for smart photovoltaic power plants as claimed in claim 5, wherein the first-stage step-down circuit uses an LM2596 chip, and the second-stage step-down circuit and the third-stage step-down circuit The circuit adopts SPX3819 chip. 7. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 5, wherein the first voltage value is 5.5V, the second voltage value is 3.3V, and the third voltage value is 5V . 8. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 4, wherein the light intensity and temperature measurement circuit includes a BH1750FVI chip for measuring light intensity and a temperature sensor DS18B20 for measuring temperature. 9. The distributed cloud monitoring system for intelligent photovoltaic power plants as claimed in claim 4, wherein the differential amplifier and analog-to-digital conversion circuit includes a differential amplifier amplifier circuit that uses the AD620 chip to amplify the small signal voltage, and uses an MCP3421 chip to perform An analog-to-digital conversion circuit for A/D conversion of the output signal. 10. The distributed cloud monitoring system for smart photovoltaic power plants according to claim 4, wherein the microprocessor is an ATmega128A single-chip microcomputer.