Distributed photovoltaic system and method based on Internet of Things technology and intelligent switch measurement and control

Abstract

The invention discloses a distributed photovoltaic system and method based on the Internet of Things technology and intelligent switch measurement and control, and the system comprises an intelligent metering and control module which is used for measuring the network access electrical parameters of all access rooms in real time, and achieves the off-network and grid connection of the distributed photovoltaic access rooms; the alternating current and direct current measurement and grouping control module is used for cutting off the photovoltaic power singly / grouping and directly adjusting the network access power of the photovoltaic power through communication between an intelligent switch and a photovoltaic inverter; power direction monitoring can be used for off-grid / grid-connected switching; communication between remote communication and a central control system is included, and real-time issuing of instructions and uploading of data are ensured; and the Internet of Things electric energy quality measurement and control module is used for monitoring the electric energy quality in real time, providing parameters for distribution operation and monitoring the influence of photovoltaic access on the electric energy quality of the power grid. According to the invention, through the intelligent measurement, metering and control module and the communication and grouping control module, the distributed photovoltaic access is effectively controlled, the voltage fluctuation and harmonic pollution of the power grid are avoided, and the stable operation is ensured.

Description

Technical Field

[0001] The present invention relates to the field of intelligent switch technology of Internet of Things technology, and in particular to a distributed photovoltaic system and method based on Internet of Things technology and intelligent switch measurement and control. Background Art

[0002] Regarding the research and application of distributed photovoltaic control technology, the current focus of work is to continuously deepen the research and development of observability, measurability, adjustability and controllability (referred to as the "four cans") of distributed photovoltaic technology, and to start a pilot project for the refined regulation of distributed photovoltaic areas.

[0003] The shortcoming of existing technologies is that distributed photovoltaic systems often present disorderly access and are difficult to regulate, which not only limits the effective support potential of distributed photovoltaic power generation to the power grid, but also leads to absorption problems and contradictions when the low-voltage side of the substation is connected to the grid. In order to meet these challenges, we are actively exploring direct collection and direct control methods for low-voltage distributed photovoltaics, aiming to develop a set of direct collection and direct control solutions for low-voltage distributed photovoltaics that are both "replicable" and "promotable", and carry out relevant precision regulation pilot projects.

[0004] In this process, we comprehensively considered the pressures faced by photovoltaic grid connection and grid regulation, and combined with the power quality factors of the terminal grid, striving to achieve the orderliness, adjustability and controllability of full-caliber distributed photovoltaics to the greatest extent. However, existing technologies still need further breakthroughs to more effectively solve the problems of distributed photovoltaic access and regulation, ensure the stable operation of the grid and the efficient use of distributed photovoltaic resources. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art. To achieve the above purpose, a distributed photovoltaic system and method based on Internet of Things technology and intelligent switch measurement and control are adopted to solve the problems raised in the above background technology.

[0006] A distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control, the system includes an intelligent metering and control module, an AC and DC measurement and grouping control module, a communication module, and an Internet of Things power quality measurement and control module;

[0007] The intelligent metering and control module is used to measure the grid voltage of each access household in real time, and control the opening / closing of the switch according to the control strategy to achieve off-grid and grid-connected access of distributed photovoltaic households;

[0008] The AC / DC measurement and grouping control module is used to remove photovoltaic panels in groups and directly adjust the grid-connected power through the metering switch;

[0009] The communication module is used to realize the communication between the intelligent metering and control module, the AC and DC measurement and grouping control module and the central control system to ensure the real-time issuance of instructions and the uploading of data;

[0010] The Internet of Things power quality measurement and control module is used to monitor the power quality of the terminal in the substation in real time, including 1st to 25th harmonics, provide parameters for operation management, and monitor the impact of photovoltaic access on the power quality of the power grid.

[0011] As a further solution of the present invention: the intelligent metering and control module includes a collection submodule for real-time measurement of the grid-connected electrical parameters of each access household, and a control instruction receiving and execution submodule for receiving control instructions from the central control system and controlling the opening / closing of switches according to the instructions, thereby realizing off-grid and grid-connected control of distributed photovoltaic access households.

[0012] As a further solution of the present invention: the AC / DC measurement and group control module includes a collection submodule for real-time measurement of parameters such as output voltage and current of photovoltaic panels, and a group control submodule for grouping photovoltaic panels through metering switches according to a control strategy.

[0013] As a further solution of the present invention: the communication module includes a communication submodule for realizing real-time communication between the intelligent metering and control module, the AC / DC measurement and grouping control module and the central control system to ensure timely issuance of instructions and accurate uploading of data, and a local storage and instruction execution submodule for storing issued instructions when communication is interrupted and automatically executing them after communication is restored.

[0014] As a further solution of the present invention: the Internet of Things power quality measurement and control module includes a monitoring submodule for real-time monitoring of electrical parameters and 1-25 harmonics, providing parameters for operation management, and a data analysis and alarm submodule for analyzing the monitored power quality data, triggering an alarm and uploading it to the central control system when the data exceeds a set threshold.

[0015] A technical solution on the other hand: A control method for a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control as described in any one of the above, comprising the following steps:

[0016] Step S1: System deployment and equipment installation:

[0017] Install smart metering and control modules, AC and DC measurement and grouping control modules, communication modules, and IoT power quality measurement and control modules in selected pilot areas;

[0018] Ensure that all modules are properly connected to the communication module and can upload data and receive instructions in real time;

[0019] Step S2: Data collection and monitoring:

[0020] Start the intelligent metering and control module and the IoT power quality measurement and control module to collect the grid voltage of each access household and the power quality data of the terminal in the substation in real time; upload the collected data to the central control system for real-time monitoring and analysis;

[0021] Step S3: Control strategy formulation and implementation:

[0022] According to the control strategy, formulate a specific implementation plan; send control instructions to the intelligent metering and control module through the central control system to control the opening / closing of the AC contactor to achieve off-grid and grid-connected access for distributed photovoltaic households;

[0023] Adopting AC / DC measurement and group control module, photovoltaic panels are removed in groups according to the control strategy to adjust the grid power;

[0024] Step S4: System debugging, monitoring, evaluation and maintenance:

[0025] Comprehensively debug the system to ensure that all modules work properly, data is accurate, and control strategies are effective;

[0026] Continuously monitor the power quality at the end of the substation area and evaluate the improvement effect of the distributed photovoltaic direct procurement and direct control system on the power quality of the power grid;

[0027] Collect user feedback, evaluate the impact of the system on distributed photovoltaic access households, and ensure that the system is replicable and scalable;

[0028] Maintain and inspect the system regularly to ensure the normal operation of the equipment, and upgrade and improve the system according to technological developments.

[0029] Compared with the prior art, the present invention has the following technical effects:

[0030] The above technical solution is adopted, and mainly includes intelligent metering and control modules, AC and DC measurement and grouping control modules, communication modules, and IoT power quality measurement and control modules. The system can effectively control and manage photovoltaic access households by real-time monitoring of the operating status of distributed photovoltaic power stations, while monitoring power quality. Automated management and remote control technology can reduce manual intervention and operating costs and improve operational efficiency. At the same time, by optimizing the project financing structure and selecting appropriate financing methods, the financing cost can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings:

[0032] Figure 1 A schematic diagram of the structure of a distributed photovoltaic system according to an embodiment disclosed in this application;

[0033] Figure 2 A schematic diagram of the steps of a control method for a distributed photovoltaic system according to an embodiment disclosed in the present application;

[0034] Figure 3 This is a schematic diagram of the equipment wiring of a distributed photovoltaic system according to an embodiment disclosed in the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Please refer to Figure 1 ,In an embodiment of the present invention, a distributed photovoltaic system based on the Internet of Things technology and intelligent switch measurement and control, the system includes an intelligent metering and control module, an AC and DC measurement and grouping control module, a communication module, and an Internet of Things power quality measurement and control module;

[0037] Intelligent metering and control module, used to measure the grid voltage of each access household in real time, and control the opening / closing of the switch according to the control strategy, so as to realize the off-grid and grid-connection of distributed photovoltaic access households;

[0038] AC / DC measurement and group control module, used to remove photovoltaic panels in groups, and to adjust the grid power through communication between DC metering switches and inverters;

[0039] Communication module, used to realize the communication between the intelligent metering and control module, AC and DC measurement and grouping control module and the central control system, ensuring the real-time issuance of instructions and uploading of data;

[0040] The IoT power quality measurement and control module is used to monitor the power quality at the end of the substation in real time, including voltage and 1-25 harmonics, provide parameters for operation management, and monitor the impact of photovoltaic access on the power quality of the grid.

[0041] Specifically, the main problems with photovoltaic access in the existing technology are: the power entering the grid varies greatly, and because it cannot be consumed locally, it causes large fluctuations in household voltage and high terminal voltage; there may be problems with household power quality, and real-time monitoring is required to obtain monitoring data and obtain first-hand information on the impact of photovoltaic power generation in the substation on the power quality of the terminal power grid.

[0042] In this embodiment, the intelligent metering and control module includes a collection submodule for real-time measurement of the grid-connected electrical parameters of each access household, and a control instruction receiving and execution submodule for receiving control instructions from the central control system and controlling the opening / closing of switches according to the instructions, thereby realizing off-grid and grid-connected control of distributed photovoltaic access households.

[0043] In this embodiment, the AC / DC measurement and group control module includes a collection submodule for measuring the output parameters of the photovoltaic panels in real time, and a group control submodule for removing the photovoltaic panels in groups through metering switches according to a control strategy.

[0044] In this embodiment, the communication module includes a communication submodule for realizing real-time communication between the intelligent metering and control module, the AC / DC measurement and grouping control module and the central control system to ensure timely issuance of instructions and accurate uploading of data, and a local storage and instruction execution submodule for storing issued instructions when communication is interrupted and automatically executing them after communication is restored.

[0045] In this embodiment, the Internet of Things power quality measurement and control module includes a voltage and harmonic monitoring submodule for real-time monitoring of the terminal voltage and 1-25 harmonics of the substation area, providing parameters for operation management, and a data analysis and alarm submodule for analyzing the monitored power quality data. When the data exceeds the set threshold, an alarm is triggered and uploaded to the central control system.

[0046] A technical solution on the other hand: A control method for a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control including any of the above items, comprising the following steps:

[0047] like Figure 2 As shown, the figure is a schematic diagram of the steps of the control method of the distributed photovoltaic system;

[0048] Step S1: System deployment and equipment installation:

[0049] Install smart metering and control modules, AC and DC measurement and grouping control modules, communication modules, and IoT power quality measurement and control modules in selected pilot areas;

[0050] Ensure that all modules are properly connected to the communication module and can upload data and receive instructions in real time;

[0051] Step S2: Data collection and monitoring:

[0052] Start the intelligent metering and control module and the IoT power quality measurement and control module to collect the grid voltage of each access household and the power quality data of the terminal in the substation in real time; upload the collected data to the central control system for real-time monitoring and analysis;

[0053] Step S3: Control strategy formulation and implementation:

[0054] According to the control strategy, formulate a specific implementation plan; send control instructions to the intelligent metering and control module through the central control system to control the opening / closing of the switch to achieve off-grid and grid-connected access for distributed photovoltaic households;

[0055] Adopting AC / DC measurement and group control module, photovoltaic panels are removed in groups according to the control strategy to adjust the grid power;

[0056] Step S4: System debugging, monitoring, evaluation and maintenance:

[0057] Comprehensively debug the system to ensure that all modules work properly, data is accurate, and control strategies are effective;

[0058] Continuously monitor the power quality at the end of the substation area and evaluate the improvement effect of the distributed photovoltaic direct procurement and direct control system on the power quality of the power grid;

[0059] Collect user feedback, evaluate the impact of the system on distributed photovoltaic access households, and ensure that the system is replicable and scalable;

[0060] Maintain and inspect the system regularly to ensure the normal operation of the equipment, and upgrade and improve the system according to technological developments.

[0061] In this embodiment, according to the above steps, the refined control scheme for photovoltaic access in the substation area includes a direct purchase and control scheme by household, a control scheme by photovoltaic panel grouping, and an online monitoring scheme for household power quality;

[0062] like Figure 3 As shown, the diagram is a scheme equipment wiring diagram of a distributed photovoltaic system;

[0063] In the figure, four DC switches are used, each controlling a different photovoltaic panel. For the grid-connection and off-grid control of the inverter, an AC switch is used. In addition, a dotted line is planned to be drawn to represent the 485 communication line, which is used to adjust the output power of the inverter.

[0064] Specifically, when each household uses an AC IoT smart metering switch, direct collection and control of each household in the area is carried out. The grid voltage of each household is collected in real time, and according to the control strategy (when the voltage exceeds the limit value, A limits the highest voltage household to connect to the grid in turn. B connects to the grid in turns on a daily basis or in batches). Through the opening / closing of the smart metering switch, the distributed photovoltaic access households can be disconnected and connected to the grid.

[0065] There are many communication methods: 4G, 5G public network, WIFI, NB, etc. The switch itself can also store the issued instructions and run automatically.

[0066] Advantages: The distributed photovoltaic direct procurement and direct control technology solution has the advantages of fast data collection, easy installation and debugging, low cost, and less construction and operation and maintenance workload.

[0067] Disadvantages: It is regulated by households, which tests the acceptance capacity of households connected to photovoltaic power plants.

[0068] Specifically, when each household uses an AC IoT smart metering switch to measure the network access parameters of each household in real time, the metering switch is used to cut in groups of photovoltaic panels connected to the grid according to the control strategy to adjust the network access power.

[0069] There are many communication methods: 4G, 5G public network, WIFI, NB, etc. The switch itself can also store the issued instructions and run automatically.

[0070] Advantages: Removal of photovoltaic panels in groups reduces access power, enables detailed regulation, and reduces customer awareness.

[0071] Disadvantages: N (N groups of solar panels) smart metering switches need to be installed in front of the inverter, which is expensive and labor-intensive, and requires customer approval. (The quotation for the solution is temporarily divided into 4 groups of photovoltaic panels per household).

[0072] Specifically, it is recommended that each substation install two IoT power quality measurement and control switches on the household side to monitor the power quality (voltage, 1-25th harmonics) in real time, to provide a reference for operation management; to monitor the impact of photovoltaic access on the power quality of the grid; and to detect the degree of influence of different photovoltaic equipment on the power quality of the grid.

[0073] Advantages: The IoT power quality measurement and control switch is small in size, simple to install, and low in cost. It can conveniently realize real-time monitoring of the power quality of the photovoltaic access point grid.

[0074] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents, and all should be included within the scope of protection of the present invention.

Claims

1. A distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control, characterized in that: The system includes an intelligent metering and control module, an AC / DC measurement and grouping control module, a communication module, and an IoT power quality measurement and control module; The intelligent metering and control module is used to measure the grid access parameters of each access household in real time, and control the opening / closing according to the control strategy to achieve off-grid and grid-connected access of distributed photovoltaic households; The AC / DC measurement and grouping control module is used to remove photovoltaic panels in groups and adjust the photovoltaic grid-connected power through the metering switch and the protocol converter; The communication module is used to realize the communication between the intelligent metering and control module, the AC and DC measurement and grouping control module and the central control system to ensure the real-time issuance of instructions and the uploading of data; The Internet of Things power quality measurement and control module is used to monitor power quality in real time, including voltage and 1-25 harmonics, provide parameters for operation management, and monitor the impact of photovoltaic access on power quality of the power grid.

2. According to claim 1, a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control is characterized in that: The intelligent metering and control module includes a submodule for collecting network access parameters of each access household in real time, and a submodule for receiving control instructions from the central control system and opening / closing according to the instructions to realize off-grid and grid-connected control of distributed photovoltaic access households.

3. According to claim 1, a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control is characterized in that: The AC / DC measurement and group control module includes a collection submodule for measuring the output voltage and current of the photovoltaic panel in real time, and a group control submodule for cutting off the photovoltaic panels in groups through metering switches according to a control strategy.

4. According to claim 1, a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control is characterized in that: The communication module includes a communication submodule for realizing real-time communication between the intelligent metering and control module, the AC / DC measurement and grouping control module and the central control system to ensure timely issuance of instructions and accurate uploading of data, and a local storage and instruction execution submodule for storing issued instructions when communication is interrupted and automatically executing them after communication is restored.

5. According to claim 1, a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control is characterized in that: The Internet of Things power quality measurement and control module includes a monitoring submodule for real-time monitoring of the electrical parameters and 1-25 harmonics at the end of the substation to provide parameters for operation, and a data analysis and alarm submodule for analyzing the power quality data. When the data exceeds the set threshold, an alarm is triggered and uploaded to the central control system.

6. A control method for a distributed photovoltaic system based on Internet of Things technology and intelligent switch measurement and control as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1: System deployment and equipment installation: Install smart metering and control modules, AC and DC measurement and grouping control modules, communication modules, and IoT power quality measurement and control modules in selected pilot areas; Ensure that all modules are properly connected to the communication module and can upload data and receive instructions in real time; Step S2: Data collection and monitoring: Start the intelligent measurement and control module and the IoT power quality measurement and control module to collect the grid voltage of each access household and the power quality data of the terminal in the substation in real time; upload the collected data to the central control system for real-time monitoring and analysis; Step S3: Control strategy formulation and implementation: According to the control strategy, formulate a specific implementation plan; send control instructions to the intelligent metering and control module through the central control system to control the opening / closing of the AC contactor to achieve off-grid and grid-connected access for distributed photovoltaic households; Adopting AC / DC measurement and group control module, photovoltaic panels are removed in groups according to the control strategy to adjust the grid power; Step S4: System debugging, monitoring, evaluation and maintenance: Comprehensively debug the system to ensure that all modules work properly, data is accurate, and control strategies are effective; Continuously monitor power quality and evaluate the improvement effect of distributed photovoltaic direct procurement and control system on power quality of power grid; Collect user feedback, evaluate the impact of the system on distributed photovoltaic access households, and ensure that the system is replicable and scalable; Maintain and inspect the system regularly to ensure the normal operation of the equipment, and upgrade and improve the system according to technological developments.

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