Power grid frequency modulation system and method based on RedCap terminal

Abstract

The invention discloses a power grid frequency modulation system and method based on a RedCap terminal, and the system comprises a photovoltaic array, a photovoltaic inverter, a concentrator, a photovoltaic cloud platform and a power distribution device, and completes the grid connection process of a photovoltaic system through the above assemblies. Wherein the concentrator is a concentrator based on a RedCap module and is used for communication in a local RS485 mode; when secondary frequency modulation needs to be carried out on the power grid, the AGC system of the photovoltaic cloud platform calculates the power amount needing to be adjusted and issues the power amount to the concentrator through a 5G network; the concentrator controls the photovoltaic inverter to adjust the active power output by the photovoltaic inverter through local RS485 communication, so that the frequency of a power grid is adjusted, the safety of secondary frequency modulation resource scheduling and the data transmission efficiency of a photovoltaic system are ensured, the power consumption and the cost of a terminal are reduced, and the power consumption of the terminal is reduced. Good communication and cooperation between a photovoltaic system and an operation control center of a power system are ensured, and effectiveness and collaboration of secondary frequency modulation control of a power grid are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of power grid frequency modulation, and in particular relates to a power grid frequency modulation system and method based on a RedCap terminal. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Secondary frequency regulation of the power grid, also known as automatic generation control (AGC), means that the generator set provides sufficient adjustable capacity and a certain regulation rate, and tracks the frequency in real time under the allowable regulation deviation to meet the requirements of system frequency stability. Secondary frequency regulation can achieve zero-difference frequency regulation and monitor and adjust the power of the tie line. There are two ways to implement secondary frequency regulation:

[0004] 1. Grid frequency regulation: The dispatcher of the central dispatching office issues load adjustment orders to each plant based on the load flow and grid frequency, and each power generation unit makes adjustments to achieve secondary frequency regulation of the entire network.

[0005] 2. Automatic Control System (AGC): Computers (computer dispatchers) remotely control the units of each plant to realize the entire frequency modulation process. Each unit participating in the system must have several coordinated control systems.

[0006] The inventors found that 4G or 5G R15 terminals are mostly used in current distributed photovoltaic systems to schedule resources for secondary frequency modulation of photovoltaic systems. However, 4G is not as good as 5G in terms of security and data transmission efficiency. 5G R15 terminals have considerable power consumption and cost, and the photovoltaic system needs to maintain good communication and coordination with the operation control center of the power system to ensure the effectiveness and coordination of frequency modulation control. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a power grid frequency regulation system and method based on RedCap terminal, which reduces the power consumption and cost of the terminal while ensuring the security of secondary frequency regulation resource scheduling of the photovoltaic system and the data transmission efficiency, and ensures good communication and coordination between the photovoltaic system and the operation control center of the power system, thereby ensuring the effectiveness and coordination of the secondary frequency regulation control of the power grid.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0009] On the one hand, the technical solution of the present invention provides a grid frequency modulation system based on RedCap terminal, including: photovoltaic array, photovoltaic inverter, concentrator, photovoltaic cloud platform and power distribution device, and the grid connection process of photovoltaic system is completed through the above components;

[0010] Among them, the concentrator is a concentrator based on the RedCap module and communicates through local RS485; when the power grid needs to be frequency-regulated for the second time, the AGC system of the photovoltaic cloud platform calculates the amount of power that needs to be adjusted and sends this power to the concentrator through the 5G network; the concentrator controls the photovoltaic inverter through local RS485 communication to adjust its output active power, thereby realizing the adjustment of the power grid frequency.

[0011] In at least one embodiment, the concentrator mainly includes a concentrator terminal and a lightweight 5G communication unit; the lightweight 5G communication unit is mounted on the concentrator terminal as a module.

[0012] In at least one embodiment, the lightweight 5G communication unit includes an antenna, a power RedCap module and a positioning module.

[0013] In at least one embodiment, the electric power RedCap module is embedded with an eSIM chip, and the electric power RedCap module is connected to the network through AT dialing.

[0014] In at least one embodiment, the power RedCap module is connected to the concentrator terminal via a USB interface to receive power data sent by the photovoltaic cloud platform.

[0015] In at least one embodiment, the power RedCap module supports a USIM card; the power RedCap module is connected to an antenna with a lightweight design using a 1T2R antenna method.

[0016] In at least one embodiment, the power RedCap communication unit is equipped with a GPS / Beidou module for positioning and timing.

[0017] In at least one embodiment, the photovoltaic array is a solar panel and its accessories.

[0018] In at least one embodiment, the power distribution device is an AC distribution box or a low-voltage grid-connected cabinet.

[0019] On the other hand, the technical solution of the present invention also provides a power grid frequency modulation method based on a RedCap terminal, comprising:

[0020] When the power dispatching center has a demand for grid frequency regulation or the grid load changes, the photovoltaic system needs to adjust the output active power. The AGC system of the photovoltaic cloud platform calculates the power that needs to be adjusted and sends instructions to adjust the grid-connected power output of the photovoltaic system to the concentrator based on the RedCap module through the 5G network;

[0021] After receiving this command, the concentrator based on the RedCap module communicates with the photovoltaic inverter through the local RS485 method and transmits the command to adjust the output power to the photovoltaic inverter;

[0022] The photovoltaic inverter adjusts the frequency of the power grid by changing the load reduction rate, PID control, and fuzzy control, completing the secondary frequency regulation process of the power grid with the participation of the photovoltaic system.

[0023] The beneficial effects of the technical solution of the present invention are as follows:

[0024] The grid frequency modulation system based on the RedCap terminal of the present invention ensures good communication and coordination between the photovoltaic system and the operation control center of the power system, ensuring the effectiveness and coordination of the secondary frequency modulation control of the grid. When performing secondary frequency modulation on the grid, a concentrator based on the RedCap module and communicating via local RS485 is used, without the need for an external processor, as well as related memory and peripheral devices, thereby reducing hardware costs; at the same time, removing the energy consumption of the external processor part not only reduces energy consumption, reduces the occupancy rate of intermediate resources, but also improves the interaction efficiency of various components between systems; moreover, data transmission through the 5G network can also ensure the security of the secondary frequency modulation resource scheduling of the photovoltaic system and the data transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a schematic diagram of a power grid frequency modulation system based on a RedCap terminal of the present invention;

[0027] Figure 2 It is a structural schematic diagram of the concentrator based on the RedCap module of the present invention.

[0028] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] Grid-connected photovoltaic system

[0031] Photovoltaic systems are mainly divided into independent systems, grid-connected systems and hybrid systems. Here we mainly introduce grid-connected photovoltaic systems. Grid-connected photovoltaic systems are mainly composed of solar cell modules (photovoltaic arrays), inverters, distribution rooms and lightning protection equipment. The biggest feature of this system is that the direct current generated by the photovoltaic array is directly connected to the mains network after being converted into alternating current that meets the requirements of the mains power grid by the grid-connected inverter. In addition to supplying the AC load, the excess power generated by the photovoltaic array in the grid-connected system is fed back to the grid. On rainy days or at night, when the photovoltaic array does not generate electricity or the electricity generated cannot meet the load requirements, it is powered by the grid. Because the electricity is directly input into the grid, it is unnecessary to configure batteries, and the process of battery energy storage and release is saved. The electricity generated by the photovoltaic array can be fully utilized, thereby reducing energy loss and reducing the cost of the system.

[0032] Grid frequency regulation

[0033] Grid frequency regulation is mainly divided into primary frequency regulation, secondary frequency regulation and tertiary frequency regulation.

[0034] Primary frequency regulation is usually defined as the function of controlling the change of the output power of the turbine by speed or power reaction when the set value of the turbine speed control system remains unchanged, so as to adapt to the change of the grid frequency. The power grid is a huge inertial system. According to the rotor motion equation, when the grid load decreases, the generator rotor accelerates and the grid frequency increases, and vice versa. Therefore, the primary frequency regulation function is one of the means to dynamically ensure the active power balance of the grid. When the grid frequency increases, the primary frequency regulation function requires the unit to reduce the grid-connected active power, and vice versa, the unit increases the grid-connected active power. The main participants in the primary frequency regulation of the grid are thermal power units and hydropower units. Some wind power, photovoltaic, and energy storage also have the ability to regulate the grid primary frequency.

[0035] Secondary frequency regulation, also known as Automatic Generation Control (AGC), means that the generator set provides sufficient adjustable capacity and a certain regulation rate, and tracks the frequency in real time under the allowable regulation deviation to meet the requirements of system frequency stability. Secondary frequency regulation can achieve zero-difference frequency regulation and monitor and adjust the tie line power.

[0036] Tertiary frequency regulation is aimed at the load that changes slowly and regularly, and coordinates the economic distribution of loads among power plants, so as to achieve economic and stable operation of the power grid. Its purpose is to reasonably utilize energy and equipment on the premise of meeting the frequency quality and safety of the power system, and to obtain the most useful electricity at the lowest power generation cost or fee.

[0037] As introduced in the background technology, the purpose of the present invention is to overcome the shortcomings existing in the above-mentioned prior art and to provide a power grid frequency regulation system and method based on RedCap terminal, which reduces the power consumption and cost of the terminal while ensuring the security of secondary frequency regulation resource scheduling of the photovoltaic system and the data transmission efficiency, and ensures that the photovoltaic system and the operation control center of the power system maintain good communication and coordination, thereby ensuring the effectiveness and coordination of the secondary frequency regulation control of the power grid.

[0038] Example 1

[0039] In a typical embodiment of the present invention, Figure 1 As shown, this embodiment discloses a power grid frequency regulation system based on RedCap terminal, including: a photovoltaic array, a photovoltaic inverter, a concentrator, a photovoltaic cloud platform and a distribution device, and the grid-connected process of the photovoltaic system is completed through the above components; wherein the concentrator is a concentrator based on the RedCap module and communicates through local RS485; when the power grid needs to be secondary frequency regulated, the AGC system of the photovoltaic cloud platform calculates the power amount that needs to be adjusted, and sends this power amount to the concentrator through the 5G network; the concentrator controls the photovoltaic inverter through local RS485 communication to adjust its output active power, thereby realizing the adjustment of the power grid frequency.

[0040] Photovoltaic array refers to solar panels and their accessories, and power distribution device refers to AC distribution box or low-voltage grid-connected cabinet. When the photovoltaic system is connected to the grid, the photovoltaic array transmits the generated DC power to the photovoltaic inverter, which converts the DC power into AC power and transmits it to the AC distribution box or low-voltage grid-connected cabinet. The AC distribution box or low-voltage grid-connected cabinet transmits the AC power to the grid to complete the grid connection process.

[0041] The photovoltaic cloud platform monitors the load and frequency changes of the power grid through AGC technology, automatically adjusts the output power of the generator, and ensures the balance of the power grid frequency and load. When the power dispatching center has the demand for power grid frequency regulation or the power grid load changes, that is, the power grid needs to be adjusted twice, the AGC system of the photovoltaic cloud platform will calculate the amount of power that needs to be adjusted, and send this power to the concentrator based on the RedCap module through the 5G network. The concentrator based on the RedCap module controls the photovoltaic inverter through local RS485 communication to adjust its output active power, thereby adjusting the power grid frequency.

[0042] like Figure 2As shown in the figure, the concentrator is a concentrator based on the RedCap module, which mainly includes a concentrator terminal and a lightweight 5G communication unit, and the lightweight 5G communication unit is mounted on the concentrator terminal as a module. The lightweight 5G communication unit includes an antenna, a power RedCap module and a positioning module. The RedCap module adopts the openCPU solution design, which can release chip-level computing power and run applications that originally need to be deployed on the terminal MCU through OpenCPU, thereby reducing the development difficulty of the whole machine and realizing efficient integration of 5G terminal network computing power. It does not require an external processor and related memory and peripheral devices, reducing hardware costs; at the same time, removing the energy consumption of the external processor part not only reduces energy consumption, reduces the occupancy rate of intermediate resources, but also improves the interaction efficiency of various components between systems.

[0043] In this embodiment, the power RedCap module is embedded with an eSIM chip, and the eSIM number of the eSIM chip is provided by the communication operator. The power RedCap module is connected to the network through AT dialing. The power RedCap module is connected to the concentrator terminal through a USB interface to receive power data sent by the photovoltaic cloud platform.

[0044] In this embodiment, the power RedCap module also supports USIM cards. When in use, you can choose either an embedded eSIM chip or an inserted USIM card. The USIM card is also provided by the operator, and the power RedCap module can be connected to the network through AT dialing.

[0045] In this embodiment, the power RedCap module is connected to an antenna with a lightweight design using a 1T2R antenna mode. The 1T2R antenna mode means one transmitting antenna and two receiving antennas. This configuration can use spatial diversity technology to receive signals through multiple receiving antennas, thereby improving signal stability and reliability, thereby increasing data transmission rate and enhancing signal coverage, and further ensuring that the photovoltaic system and the operation control center of the power system maintain good communication and coordination to ensure the effectiveness and coordination of frequency modulation control.

[0046] In this embodiment, the power RedCap communication unit is equipped with a GPS / Beidou module for positioning and timing. The positioning function ensures the safety, easy monitoring and easy maintenance of the power terminal, and the timing function can ensure the synchronization between various devices during the secondary frequency modulation of the power grid, thereby improving the stability and reliability of the entire power system during the frequency modulation process.

[0047] The power grid frequency regulation system based on RedCap terminal proposed in this embodiment reduces the power consumption and cost of the terminal while ensuring the security of the secondary frequency regulation resource scheduling of the photovoltaic system and the data transmission efficiency, ensuring good communication and coordination between the photovoltaic system and the operation control center of the power system, and ensuring the effectiveness and coordination of the secondary frequency regulation control of the power grid.

[0048] Example 2

[0049] In a typical implementation of the present invention, this embodiment discloses a power grid frequency modulation method based on a RedCap terminal, comprising:

[0050] When the power dispatching center has a demand for grid frequency regulation or the grid load changes, the photovoltaic system needs to adjust the output active power. The AGC system of the photovoltaic cloud platform calculates the power that needs to be adjusted and sends instructions to adjust the grid-connected power output of the photovoltaic system to the concentrator based on the RedCap module through the 5G network;

[0051] After receiving this command, the concentrator based on the RedCap module communicates with the photovoltaic inverter through the local RS485 method and transmits the command to adjust the output power to the photovoltaic inverter;

[0052] The photovoltaic inverter adjusts the frequency of the power grid by changing the load reduction rate, PID control, and fuzzy control, completing the secondary frequency regulation process of the power grid with the participation of the photovoltaic system.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power grid frequency modulation system based on RedCap terminal, characterized in that: include: Photovoltaic arrays, photovoltaic inverters, concentrators, photovoltaic cloud platforms and power distribution devices, and the photovoltaic system grid connection process is completed through the above components; Among them, the concentrator is a concentrator based on the RedCap module and communicates through local RS485; when the power grid needs to be frequency-regulated for the second time, the AGC system of the photovoltaic cloud platform calculates the amount of power that needs to be adjusted and sends this power to the concentrator through the 5G network; the concentrator controls the photovoltaic inverter through local RS485 communication to adjust its output active power, thereby realizing the adjustment of the power grid frequency.

2. A power grid frequency modulation system based on RedCap terminal as claimed in claim 1, characterized in that: The concentrator mainly includes a concentrator terminal and a lightweight 5G communication unit; the lightweight 5G communication unit is mounted on the concentrator terminal as a module.

3. A power grid frequency modulation system based on RedCap terminal as claimed in claim 2, characterized in that: The lightweight 5G communication unit includes an antenna, a power RedCap module and a positioning module.

4. A RedCap terminal-based power grid frequency modulation system as claimed in claim 3, characterized in that: The electric power RedCap module is embedded with an eSIM chip, and the electric power RedCap module is connected to the network through AT dialing.

5. A RedCap terminal-based power grid frequency modulation system as claimed in claim 3, characterized in that: The power RedCap module is connected to the concentrator terminal via a USB interface to receive power data sent by the photovoltaic cloud platform.

6. A RedCap terminal-based power grid frequency modulation system as claimed in claim 3, characterized in that: The power RedCap module supports the USIM card; the power RedCap module is connected to an antenna with a lightweight design using a 1T2R antenna method.

7. A RedCap terminal-based power grid frequency modulation system as claimed in claim 1, characterized in that: The power RedCap communication unit is equipped with a GPS / Beidou module for positioning and timing.

8. A RedCap terminal-based power grid frequency modulation system as claimed in claim 1, characterized in that: The photovoltaic array is a solar panel and its accessories.

9. A RedCap terminal-based power grid frequency modulation system as claimed in claim 1, characterized in that: The power distribution device is an AC distribution box or a low-voltage grid-connected cabinet.

10. A method for power grid frequency modulation based on RedCap terminal, characterized in that: include: When the power dispatching center has a demand for grid frequency regulation or the grid load changes, the photovoltaic system needs to adjust the output active power. The AGC system of the photovoltaic cloud platform calculates the power that needs to be adjusted and sends instructions to adjust the grid-connected power output of the photovoltaic system to the concentrator based on the RedCap module through the 5G network; After receiving this command, the concentrator based on the RedCap module communicates with the photovoltaic inverter through the local RS485 method and transmits the command to adjust the output power to the photovoltaic inverter; The photovoltaic inverter adjusts the frequency of the power grid by changing the load reduction rate, PID control, and fuzzy control, completing the secondary frequency regulation process of the power grid with the participation of the photovoltaic system.

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