Photovoltaic roof grid-connected photovoltaic power station distributed data acquisition monitoring system, method and device

Abstract

The application discloses a kind of photovoltaic roof grid-connected photovoltaic power station distributed data acquisition monitoring system, method, device and storage medium, including S7-1500PLC as core controller, PROFINET I / O distributed module acquires photovoltaic power station operating parameter, using decentralized control, centralized management mode;PROFINET I / O distributed module acquires photovoltaic power station operating parameter;Before inverter accesses power grid, voltage harmonic table and current harmonic table and three-phase comprehensive electric meter collect the voltage and current harmonic of each phase, voltage and current value, calculate the data of three-phase, including total power, power factor, cumulative kilowatt-hour, convert analog signal into PROFINET network digital signal at power generation site, by PROFINET bus into central controller S7-1500PLC, central controller S7-1500PLC is used for centralized management.

Description

Technical Field

[0001] This invention relates to the field of data acquisition and monitoring, and in particular to a distributed data acquisition and monitoring system, method and apparatus for a rooftop grid-connected photovoltaic power station. Background Technology

[0002] In recent years, many countries have launched or planned rooftop photovoltaic (PV) grid-connected power generation projects, and the annual installed capacity of PV grid-connected power generation has been increasing year by year. PV grid-connected power generation systems have become a booming high-tech industry. Sunlight shines on the surface of rooftop PV panels, which, after passing through an inverter, generate alternating current (AC). A portion of this electricity is used by AC loads, while the excess is fed back to the grid, thus achieving rooftop grid-connected power generation. The entry of rooftop grid-connected PV power generation into the electricity market will promote the development of green and low-carbon energy in my country.

[0003] Due to the diverse and dispersed nature of the parameters collected by rooftop photovoltaic power stations, the monitoring system for rooftop grid-connected photovoltaic power stations adopts a distributed data acquisition system. It utilizes distributed PROFINET I / O modules and smart meters to collect field data. The monitoring system transmits the collected data to the central controller S7-1500 PLC in the control room via industrial Ethernet for processing, and then transmits it to the monitoring computer for centralized display and monitoring.

[0004] The distributed data acquisition and monitoring system for grid-connected rooftop photovoltaic power plants can not only collect and store multiple power parameters of the photovoltaic power plant operation, but also monitor the operating parameters of photovoltaic modules, as well as environmental parameters such as solar irradiance, atmospheric wind speed, and indoor and outdoor temperatures of the photovoltaic power plant. Summary of the Invention

[0005] 1. Purpose of this invention

[0006] This invention adopts the design concept of centralized monitoring and management and decentralized acquisition and control, and proposes a distributed PROFINET I / O fieldbus network data acquisition and monitoring system for rooftop grid-connected photovoltaic power plants.

[0007] 2. The technical solution adopted in this invention

[0008] This invention proposes a distributed data acquisition and monitoring system for a rooftop grid-connected photovoltaic power station. It includes a human-machine interface monitoring software development platform using WinCC configuration software, an S7-1500 PLC as the core controller, and PROFINET I / O distributed modules to collect photovoltaic power station operating parameters. The system employs a distributed control and centralized management approach. The PROFINET I / O distributed modules, used for distributed control, collect photovoltaic power station operating parameters. Before the inverter connects to the grid, voltage and current harmonic meters, as well as a three-phase integrated power meter, collect voltage and current harmonics and voltage and current values ​​for each phase. The system calculates three-phase data including total power, power factor, and cumulative electricity consumption. At the power generation site, the analog signals are converted into PROFINET network digital signals and sent to the central controller S7-1500 PLC via the PROFINET bus. The central controller S7-1500 PLC is used for centralized management.

[0009] Preferably, the operating parameters of the photovoltaic power station at the power generation site include the DC input voltage and current values, the AC output voltage, current, frequency, power factor, and other values, as well as the ambient temperature, the temperature of different photovoltaic modules, solar irradiance, and wind speed.

[0010] Preferably, a three-tiered hierarchical structure is adopted, including a direct control level, a process management level, and a production management level;

[0011] The direct control layer is connected to various field devices, monitors and controls the connected devices, and connects to the central controller S7-1500 PLC to receive management information from the upper level and transmit the characteristic data of the devices and the real-time data collected.

[0012] At the process management level, optimization and monitoring are performed on computers, operator stations, and engineer stations. This involves comprehensively monitoring all information from each station in the process, centrally displaying operations, controlling loop configurations and parameter modifications, and optimizing process processing. At the process management level, the primary task is to handle overall optimization within the unit and generate precise commands for its subordinate levels.

[0013] The production management level is where the management computer coordinates the parameter settings of each unit based on the characteristics of each component of the photovoltaic power station. It is used for the overall coordination and control of the photovoltaic power station and for comprehensive management of the photovoltaic power station.

[0014] Preferably, the direct control level:

[0015] The data acquisition module performs process data acquisition; that is, it quickly acquires each process quantity and status information in the controlled equipment, and obtains input information for digital control, open-loop control, equipment monitoring, and status reporting.

[0016] The process control module performs direct digital process control: it implements real-time control of process quantities based on the control configuration database and the control algorithm module.

[0017] The diagnostic testing module performs equipment monitoring and system testing and diagnosis: after extracting process variables and status information, it analyzes whether they are acceptable and whether they can be transmitted to higher levels; thereby determining whether to adjust the controlled device; and based on the status information, it judges the performance and function of the system hardware and software, and performs alarms, errors, or diagnoses.

[0018] The security and redundancy monitoring module identifies system hardware or software malfunctions and switches to backup components.

[0019] Preferred, process management level, including:

[0020] The process control optimization module is based on the mathematical model of the process and the given control object. The optimization control is only activated when the optimization execution conditions are met, and it completes the optimization of the control process under multiple strategy conditions.

[0021] The optimized control strategy module, based on the desired values ​​of process parameters, uses digital control optimization strategies. When field conditions change, the new setpoints and adjustment values ​​are obtained through calculation and processing by the process management-level computer, and the adjustment values ​​are transmitted to the direct process control layer.

[0022] The execution module is optimized, and the devices within the unit are optimized. Based on the load and energy usage within the unit, the relationships between them are coordinated according to optimization criteria.

[0023] The optimized process monitoring module acquires real-time data from the direct control layer to monitor activities within the unit, archive faults, archive historical data, report status, and provide backup.

[0024] Preferably, the production management layer is responsible for the generation, monitoring, and product reporting of electricity from grid-connected rooftop photovoltaic power plants, and for exchanging data with the upper layer.

[0025] This invention proposes a detection method, comprising:

[0026] It establishes communication connections with each data acquisition module and has an automatic reconnection function after communication interruption;

[0027] Real-time monitoring of the operation data of grid-connected photovoltaic power plants, including the electrical parameters of solar cell modules and the cumulative electrical energy parameters fed into the grid by the power plant;

[0028] Plot the voltage-current curve and power-time curve of the inverter;

[0029] This includes data management for storing historical data, exporting data, and generating daily, monthly, and annual reports;

[0030] It employs a two-level password management system, with the system administrator possessing the highest administrative authority.

[0031] Preferred methods include data acquisition, processing, storage, display, and querying;

[0032] Data acquisition includes the electrical parameters output by the solar modules, the cumulative electrical energy fed into the grid, the input and output parameters of the grid-connected inverter, total solar radiation, wind speed, and the surface temperature of different solar modules. After data processing, the collected data is displayed in real time, and all data on the operation of the photovoltaic power station is stored, with a storage period of n minutes. It records all power generation and data storage, warning and fault information, and equipment operating status in years, months, and days. It continuously stores all operating data and fault information of the photovoltaic power station for more than m years.

[0033] Enter each monitoring interface, click the function control key, and you can query all monitored data for the current day and previous days; back up system data in spreadsheet format, and display the system's operating status using bar charts;

[0034] The monitoring software has network monitoring capabilities. The human-machine interface monitoring software and the lower-level PLC controller communicate via PROFINET to achieve remote monitoring of the system.

[0035] This invention proposes a distributed data acquisition and monitoring device for a rooftop grid-connected photovoltaic power station, comprising a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps described above.

[0036] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0037] 3. Beneficial effects of the present invention

[0038] (1) The present invention adopts a distributed data acquisition and monitoring architecture. The data acquisition equipment in the system has digital transmission function. It converts analog signals into PROFINET network digital signals at the power generation site and transmits the digital signals to the monitoring computer in the central control room through the PROFINET bus. This overcomes the signal attenuation and signal interference problems of analog signals during remote transmission and improves the reliability of the monitoring system.

[0039] (2) The hierarchical distributed system of the present invention, the distributed data acquisition and monitoring system for photovoltaic rooftop grid-connected photovoltaic power stations, can realize the acquisition and processing of photovoltaic power station data. It uses a dynamic database to store real-time data transmitted from the lower layer of the system, as well as signal analysis, waveform display, feature extraction and communication.

[0040] In summary, this invention, by collecting operational data from grid-connected rooftop photovoltaic power stations, analyzes the operational performance and efficiency of these stations, providing practical application references for building larger-capacity and larger-scale grid-connected photovoltaic power stations, and promoting the application of green and environmentally friendly grid-connected photovoltaic power generation technology in my country. Attached Figure Description

[0041] Figure 1 A diagram illustrating the network structure and hardware system of a distributed data acquisition and monitoring system for a rooftop grid-connected photovoltaic power station.

[0042] Figure 2 Structure diagram of distributed data acquisition and monitoring software for rooftop grid-connected photovoltaic power stations;

[0043] Figure 3 This is a direct control level architecture diagram;

[0044] Figure 4 This is a process management level structure diagram. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0046] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0047] Example 1

[0048] This invention uses WinCC configuration software as a human-machine interactive monitoring software development platform, an S7-1500 PLC as the core controller, and PROFINET I / O distributed modules to collect photovoltaic power station operating parameters. Drawing on the concept of "distributed control and centralized management," a distributed data acquisition and monitoring system for rooftop grid-connected photovoltaic power stations is designed. The distributed data acquisition and monitoring system adopts PROFINET industrial Ethernet, leveraging the main advantages of high-speed Ethernet to overcome the transmission rate limitations of other buses. A hierarchical distributed approach is used to construct the monitoring system network structure. A key feature of this invention is the integration of PROFINET industrial Ethernet technology and distributed data acquisition technology into the grid-connected photovoltaic power station monitoring system.

[0049] I. PROFINET Network Structure for Distributed Data Acquisition and Monitoring System

[0050] This invention adopts a layered structure similar to a DCS system, using a three-level hierarchical structure consisting of a direct control level, a process management level, and a production management level. Each level performs the following functions:

[0051] 1. Direct control level

[0052] The direct control layer is the foundation of the PROFINET network architecture for distributed data acquisition and monitoring systems. It connects directly to various field devices, monitoring and controlling them. Simultaneously, it connects upwards to the controllers in the second layer, receiving management information and transmitting device characteristic data and acquired real-time data. Its main tasks include:

[0053] (1) Process data acquisition: that is, to quickly acquire each process quantity and status information in the controlled equipment so that the processes of digital control, open-loop control, equipment monitoring, status reporting, etc. can obtain the required input information.

[0054] (2) Perform direct digital process control: Implement real-time control of process quantities (such as switching quantities, analog quantities, etc.) based on the control configuration database and control algorithm module.

[0055] (3) Conduct equipment monitoring and system testing and diagnosis: After extracting process variables and status information, analyze whether they are acceptable and whether they can be transmitted to higher levels. Further determine whether to adjust the controlled device; and judge the performance and function of the system hardware and software based on the status information, and implement alarm, error or diagnostic reporting measures when necessary.

[0056] (4) Implement security and redundancy measures: Once a hardware or software malfunction is detected, immediately switch to a backup device to ensure the safe operation of the entire system.

[0057] 2. Process Management Level

[0058] At this level, process management computers mainly include monitoring computers, operator stations, and engineer stations. They comprehensively monitor all information from each station in the process, centrally display operations, configure control loops and modify parameters, and optimize process processing. The process management level primarily handles overall optimization within the unit and generates precise commands to its lower levels. Functions at this level include:

[0059] (1) Optimization process control: Based on the mathematical model of the process and the given control object, optimization control can only be achieved under the condition that the optimization execution conditions are guaranteed. Even under different strategy conditions, the optimization of the control process can still be completed.

[0060] (2) Based on the desired values ​​of process parameters, optimization strategies are implemented through digital control. When field conditions change, new setpoints and adjustment values ​​are obtained through calculation and processing by the process management-level computer, and the adjustment values ​​are transmitted to the direct process control layer.

[0061] (3) Optimize the devices within the unit to ensure close coordination. Based on the load and energy usage within the unit, coordinate the relationships between them using optimization criteria.

[0062] (4) By acquiring real-time data from the direct control layer, the unit can perform activities monitoring, fault detection and archiving, historical data archiving, status reporting and backup.

[0063] 3. Production Management Level

[0064] At this level, the management computer coordinates the parameter settings of each unit based on the characteristics of each component of the photovoltaic power station. It acts as the overall coordinator and controller of the photovoltaic power station, and its main task is to comprehensively manage the photovoltaic power station. Power generation, monitoring, and product reporting for grid-connected rooftop photovoltaic power stations are also implemented at this level, and data is exchanged and transmitted with the upper levels.

[0065] This invention is a typical hierarchical distributed system. The distributed data acquisition and monitoring system for rooftop grid-connected photovoltaic power plants can realize the acquisition and processing of photovoltaic power plant data. It uses a dynamic database to store real-time data transmitted from the lower layers of the system, as well as signal analysis, waveform display, feature extraction, and communication.

[0066] II. Hardware Design of Monitoring System for Rooftop Grid-Connected Photovoltaic Power Stations

[0067] The distributed I / O module collects and transmits signals including DC input voltage and current values, AC output voltage, current, frequency, power factor, and other values, as well as environmental parameters such as ambient temperature, temperature of different photovoltaic modules, solar irradiance, and wind speed. Before the inverter is connected to the grid, voltage and current harmonic meters, current and voltage harmonics meters, and a three-phase integrated power meter collect voltage and current harmonics and voltage and current values ​​for each phase, and calculate data such as total three-phase power, power factor, and cumulative electricity consumption. This data is also sent to the central controller S7-1500 PLC via the PROFINET bus.

[0068] This invention employs a distributed data acquisition and monitoring scheme. The data acquisition equipment in the system must have digital transmission capabilities; therefore, the entire design emphasizes digitalization in its hardware. Distributed remote digital I / O modules, commonly used in industrial applications, are selected to convert analog signals into PROFINET network digital signals at the power generation site. These digital signals are then transmitted to the monitoring computer in the central control room via the PROFINET bus. This scheme overcomes the signal attenuation and interference problems associated with analog signals during long-distance transmission, improving the reliability of the monitoring system. The network structure and hardware system diagram of the distributed data acquisition and monitoring system for a rooftop grid-connected photovoltaic power station are shown below. Figure 1 As shown.

[0069] III. Software Design for Monitoring System of Rooftop Grid-Connected Photovoltaic Power Station

[0070] The main functions of the monitoring system software are data acquisition, processing, storage, display, and querying. The main parameters acquired include the electrical parameters output by the solar modules, the cumulative electrical energy fed into the grid, the input and output parameters of the grid-connected inverter, total solar radiation, wind speed, and the surface temperature of different solar modules. After data processing, the acquired data is displayed in real time, and all operational data of the photovoltaic power station is stored with a storage period of three minutes. It records all power generation and data storage, warning and fault information, and equipment operating status in years, months, and days. It can continuously store over ten years of operational data and fault information for the photovoltaic power station. Accessing each monitoring interface and clicking the function control keys provides the ability to query all monitored data for the current day and previous days. System data can be backed up using spreadsheets, and the system's operating status can be displayed using bar charts. The monitoring software also includes network monitoring functionality. The human-machine interface monitoring software and the lower-level PLC controller communicate via PROFINET to achieve remote system monitoring. The structure of the distributed data acquisition and monitoring software for a grid-connected photovoltaic rooftop photovoltaic power station is as follows: Figure 2 As shown.

[0071] The monitoring system for grid-connected rooftop photovoltaic power plants is designed with the following functions:

[0072] (1) Communication Management: The system automatically establishes communication connections with each data acquisition module and has the function of automatically reconnecting after communication interruption;

[0073] (2) Monitoring function: It can monitor the operation data of grid-connected photovoltaic power stations in real time, including the electrical parameters of solar cell modules, the cumulative electrical energy fed into the grid by the power station, and other parameters.

[0074] (3) Plotting curves: You can plot the voltage-current curve and power-time curve of the inverter;

[0075] (4) Data management: including historical data storage, data export, generation of daily reports, monthly reports and annual reports, etc.

[0076] (5) Password management: The system adopts a two-level password management system, and the system administrator has the highest management authority.

[0077] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A photovoltaic roof grid-connected photovoltaic power station distributed data acquisition monitoring system, characterized in that: an S7-1500 PLC is used as a core controller, PROFINET I / O distributed modules are used to acquire photovoltaic power station operating parameters, and a decentralized control and centralized management mode is adopted; the PROFINET I / O distributed modules for decentralized control acquire photovoltaic power station operating parameters; before the inverter is connected to the power grid, a voltage harmonic table, a current harmonic table, and a three-phase comprehensive power meter acquire the voltage and current harmonics, voltage and current values of each phase, calculate three-phase data including total power, power factor, and cumulative kilowatt-hour, convert analog signals into PROFINET network digital signals at the power generation site, and send them to the central controller S7-1500 PLC through the PROFINET bus; and the central controller S7-1500 PLC is used for centralized management; A three-level hierarchical structure is adopted, including a direct control level, a process management level, and a production management level; The direct control layer is connected with various devices in the field, monitors and controls the connected devices, is connected with the central controller S7-1500 PLC, receives management information from the upper layer, and transmits device characteristic data and collected real-time data to the upper layer; The process management level is used for optimization, monitoring computers, operation stations, and engineer stations; All information of the process stations is monitored and displayed, control loop configuration and parameter modification are controlled, and process treatment is optimized; The process management level mainly deals with overall optimization of the unit and generates accurate commands to the lower layer; The production management level coordinates parameter setting of each unit level according to characteristics of photovoltaic power station components, is used for overall coordination and control of the photovoltaic power station, and comprehensively manages the photovoltaic power station. The photovoltaic power station operating parameters at the power generation site include DC input voltage and current values, AC output voltage, current, frequency, power factor values, environmental temperature, temperature of different photovoltaic components, solar radiation intensity, and wind speed environmental parameters.

2. The photovoltaic rooftop grid-connected photovoltaic power plant distributed data acquisition monitoring system according to claim 1, characterized in that: The direct control level:

3. The photovoltaic rooftop grid-tied photovoltaic power plant distributed data acquisition monitoring system according to claim 1, characterized in that, A data acquisition module acquires process data, that is, quickly acquires each process quantity and state information in the controlled equipment, and obtains input information of digital control, open-loop control, equipment monitoring, and state reporting processes; A process control module directly controls the process: according to a control configuration database and a control algorithm module, the process quantity is controlled in real time; A diagnostic test module monitors equipment and tests and diagnoses the system: after the process variable and state information are taken out, whether they can be accepted and whether they can be allowed to be transmitted to the upper layer are analyzed, so as to determine whether the controlled device is adjusted; and the performance and function of the system hardware and software are judged according to the state information, and alarm, error, or diagnosis is performed; A safety and redundancy monitoring module identifies system hardware or software failure and switches to a spare part. The process management level includes:

4. The photovoltaic rooftop grid-tied photovoltaic power plant distributed data acquisition monitoring system according to claim 3, characterized in that, An optimized process control module optimizes control according to a process mathematical model and a given control object: optimization control is started only when optimization execution conditions are met, and optimization of the control process under multiple policy conditions is completed; ​ An optimization control strategy module, based on the process parameter desired value, through the optimization strategy of digital control; when the field conditions change, the new set value and adjustment value are obtained through the operation processing of the process management level computer, and the adjustment value is transmitted to the direct process control layer; An optimization execution module, the devices in the optimization unit coordinate with each other according to the load in the unit and the use of energy according to the optimization criteria; An optimization process detection module, through the real-time data of the direct control layer, the activity monitoring in the unit, fault detection archive, historical data archive, status report and backup are performed.

5. The photovoltaic rooftop grid-tied photovoltaic power plant distributed data acquisition monitoring system according to claim 1, characterized in that: The production management level realizes the production, monitoring and product report of the photovoltaic roof grid-connected photovoltaic power station, and interacts with the upper layer to transmit data.

6. A detection method of a monitoring system according to claim 1, characterized in that: A communication connection is established with each data acquisition module, and has the function of automatic reconnection after communication interruption; Real-time monitoring of the operation data of the grid-connected photovoltaic power station, including the electrical parameters of the solar cell module, the cumulative power parameters of the power station fed into the grid; Drawing the voltage-current curve and power-time curve of the inverter; Including data management of historical data storage, data export, generation of daily report, monthly report and annual report; Two-level password management is adopted, and the system administrator has the highest management right.

7. The detection method according to claim 6, characterized in that: Including data acquisition, processing, storage, display and query; Data acquisition includes the electrical parameters of the solar module output, the cumulative power fed into the grid, the input and output parameters of the grid-connected inverter, the total solar radiation, the wind speed and the surface temperature of different solar modules; after data processing, the real-time operation data of the site is displayed, all data of the photovoltaic power station are stored, the storage period is n minutes; all power generation and data storage, warning fault information and equipment operation state are recorded in the time unit of year, month and day; all operation data and fault information of the photovoltaic power station for more than m years are stored uninterruptedly; Entering each monitoring interface, clicking the function control key to provide the function of querying all monitored data on the same day and before; backing up system data in the form of an electronic table, and displaying the running status of the system using a column chart; The monitoring software has network monitoring function, and the man-machine interactive monitoring software and the lower computer PLC controller use PROFINET communication to realize remote monitoring of the system.

8. A photovoltaic roof grid-connected photovoltaic power station distributed data acquisition monitoring device, comprising a memory and a processor, the memory storing a computer program, characterized in that; The processor executes the computer program to realize the method steps of any one of claims 6-7.

9. A computer readable storage medium having stored thereon a computer program, characterized in that: The computer program is executed by the processor to realize the method steps of any one of claims 6-7.

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