New energy off-network quantity real-time calculation method and system based on alternating current and direct current faults

Abstract

The invention discloses a new energy off-network quantity real-time calculation method and system based on alternating current and direct current faults, and the method comprises the steps: obtaining the operation states of direct current and important alternating current lines in a new energy plant station or a new energy power generation region, and carrying out the discrimination of the alternating current and direct current faults; when it is judged that the alternating current and direct current fault occurs, the sum of outgoing line section power before the fault and the sum of current outgoing line section power are obtained respectively; and obtaining a new energy off-network quantity according to a difference value between the sum of the outgoing line section power before the fault and the sum of the current outgoing line section power. By monitoring the power change of the outgoing line section of the new energy plant station or the sending section of the new energy power generation area, the new energy off-network quantity is quickly and accurately calculated, reliable data support is provided for power grid dispatching decision, fault processing and power supply recovery, the safety stability and the power supply reliability of a power grid are improved, and the power supply efficiency is improved. And meanwhile, the impact of new energy offline on the power grid is reduced through alarm and control functions.

Description

Technical Field

[0001] This invention belongs to the field of power system automation, specifically relating to a method and system for real-time calculation of the amount of new energy disconnected from the grid based on AC / DC faults. Background Technology

[0002] With the large-scale integration of new energy sources such as wind power and photovoltaics into the power grid, the impact of new energy disconnection incidents on the safe and stable operation of the power grid is becoming increasingly prominent. Accurately and quickly calculating the amount of new energy disconnection is crucial for power grid dispatching decisions, fault handling, and power restoration. Currently, existing methods for calculating disconnection mainly rely on post-event statistics, which cannot reflect changes in new energy power generation during a fault in real time, thus failing to meet the needs of rapid decision-making by the power grid. Therefore, there is an urgent need for a method that can accurately calculate the amount of new energy disconnection in real time, leading to this research. Summary of the Invention

[0003] The purpose of this invention is to provide a real-time calculation method and system for renewable energy grid disconnection based on AC / DC faults. By monitoring the power changes at the outgoing lines of renewable energy plants or the transmission lines of renewable energy power generation areas, the invention enables rapid and accurate calculation of renewable energy grid disconnection, providing reliable data support for grid dispatching decisions, fault handling, and power restoration, thereby improving grid security and stability and power supply reliability. At the same time, the invention reduces the impact of renewable energy grid disconnection on the grid through alarm and control functions.

[0004] To achieve the above objectives, the solution of the present invention is:

[0005] A real-time calculation method for renewable energy grid disconnection based on AC / DC faults, comprising:

[0006] Obtain the operating status of DC and important AC lines in new energy power plants or new energy power generation areas, and identify AC and DC faults;

[0007] When determining that an AC or DC fault has occurred, the power of the outgoing line section before the fault and the power of the current outgoing line section are obtained respectively.

[0008] The amount of new energy source disconnected from the grid is obtained by comparing the sum of the outgoing line power before the fault with the sum of the current outgoing line power.

[0009] This includes acquiring the operating status of DC and important AC lines in new energy power plants or areas, and identifying AC / DC faults, including...

[0010] Identify the DC and important AC lines in new energy power plants or new energy power generation areas; among them, AC lines that are directly connected to the near end of new energy sources in new energy power plants or new energy power generation areas or have a significant impact on the voltage of the area are designated as important AC lines.

[0011] The voltage and current data of the DC and important AC lines are collected in real time, and the AC / DC fault is determined based on the voltage and current data.

[0012] Among them, obtaining the outgoing line cross-sectional power includes,

[0013] Determine the transmission section of the new energy plant or new energy power generation area;

[0014] Real-time acquisition of three-phase voltage and current data for each return transmission line at the sending section;

[0015] Based on the three-phase voltage and current data, the power of each transmission line is obtained;

[0016] Based on the power of each transmission line, the outgoing line cross-sectional power is obtained.

[0017] The transmission section consists of all AC lines for power transmission from new energy power plants or all AC lines for power transmission from new energy power generation areas.

[0018] The amount of new energy source disconnected from the grid is obtained by comparing the sum of the outgoing line cross-section power before the fault with the sum of the current outgoing line cross-section power, including:

[0019] Get the outgoing line cross-sectional power at a certain point before the fault, and get the current real-time outgoing line cross-sectional power.

[0020] The difference between the sum of the outgoing line section power and the sum of the outgoing line section power in the current real-time period before the fault is the amount of new energy disconnected from the grid.

[0021] The above methods also include,

[0022] When an AC / DC fault is detected, the power or current change information flag of the AC / DC fault is changed from 0 to 1, and the widening and holding time of the flag is determined.

[0023] During the duration of the widening and holding of the flag bit, obtain the total offline capacity;

[0024] The total disconnection capacity is compared with a set margin. When the total disconnection capacity exceeds the set margin, an alarm for exceeding the disconnection limit is issued or control measures are taken to reduce the impact on the power grid.

[0025] The total off-grid capacity mentioned above is the sum of the off-grid amounts of all new energy power plants or the off-grid amounts of the transmission sections of new energy power generation areas.

[0026] A real-time calculation system for renewable energy grid disconnection based on AC / DC faults includes,

[0027] The AC / DC fault detection module is configured to acquire the operating status of DC and important AC lines in new energy power plants or new energy power generation areas, and to detect AC / DC faults.

[0028] The line power acquisition module is configured to, upon determining that an AC / DC fault has occurred, acquire the power of the outgoing line section before the fault and the sum of the power of the current outgoing line section; and,

[0029] The real-time grid disconnection calculation module is configured to obtain the amount of new energy disconnected from the grid based on the difference between the sum of the outgoing line section power before the fault and the sum of the current outgoing line section power.

[0030] When the AC / DC fault detection module determines that an AC / DC fault has occurred, it changes the power or current change information flag of the AC / DC fault from 0 to 1 and determines the widening and holding time of the flag.

[0031] The real-time calculation module for the amount of data removed from the network obtains the total amount of data removed from the network during the time the flag is stretched and held.

[0032] It also includes,

[0033] The output and alarm module is configured to display the total offline capacity and to issue an alarm message when the offline capacity exceeds a set margin.

[0034] By adopting the above scheme, this invention, through real-time acquisition of AC / DC line fault information and renewable energy transmission section power information, can quickly and accurately calculate the amount of renewable energy disconnected from the grid after a fault occurs. Compared with traditional post-event statistical methods, this greatly improves the real-time performance and accuracy of disconnection calculation. In terms of grid dispatching decisions, real-time and accurate disconnection data provides a reliable basis for dispatchers to formulate reasonable dispatching strategies, helping to quickly adjust grid operation modes and ensure the safe and stable operation of the grid. During fault handling and power restoration, it enables maintenance personnel to promptly grasp the renewable energy disconnection situation, accelerate fault investigation and handling, shorten power outage time, and improve power supply reliability. Furthermore, the system's alarm and control functions can effectively reduce the impact of renewable energy disconnection on the grid, enhancing the grid's resilience. Attached Figure Description

[0035] Figure 1 This is a flowchart of an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the software architecture of the present invention;

[0037] Figure 3 This is a schematic diagram of the architecture of a real-time calculation system for new energy grid disconnection based on AC / DC faults provided in an embodiment of the present invention. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below, with example architectural diagrams of these embodiments shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a method for real-time calculation of renewable energy grid disconnection based on AC / DC faults, including the following steps:

[0040] Step 1: First, based on the transmission line layout of the new energy plant or new energy power generation area, determine the transmission section. Install data acquisition devices at the relevant substations of the transmission section of the new energy plant or new energy power generation area to collect the three-phase voltage and current of each transmission line in real time and calculate the power of the transmission line. Summarize the power of the transmission section. The relevant data acquisition devices have the ability to communicate with remote equipment and can send the power information to the remote plant through the communication processing module.

[0041] Step 2: Identify the DC and important AC lines within the area. Deploy fault acquisition devices in the areas where the DC and important AC lines are located to monitor the operating status of the DC or important AC lines in real time. Specifically, the devices can collect the voltage and current of the DC and important AC lines, detect sudden changes in power and current of the AC and DC lines, and identify faults. When a fault occurs, the devices can correctly identify the fault and generate corresponding fault flag bits, and generate relevant fault information or current or power change start information. The acquisition devices have the ability to communicate with remote substations and can send relevant fault information or change start information to remote substations through the communication processing module.

[0042] Step 3: Set up a strategy discrimination master station in the high voltage level power plant. The master station has the ability to communicate with the acquisition equipment related to Step 1 and Step 2, receive power information sent by the acquisition equipment of the new energy power plant or the new energy power generation area power plant, calculate the power of each section, and receive DC or AC fault information and power or current change information sent by DC and important AC power plants.

[0043] Step 4: When an AC / DC fault occurs, the power or current surge information flag of the AC / DC fault changes from 0 to 1, and the system immediately starts the grid disconnection calculation program. The system retrieves the outgoing line section power and data recorded 200ms before the fault and compares it with the currently collected and calculated outgoing line section power. The difference between the two is the new energy grid disconnection amount.

[0044] Step 5: For setting the extension and holding time of DC fault information, based on actual power grid operation experience and simulation analysis conclusions, and taking into account the impact time of AC / DC faults on the power grid and the maximum time required for the low voltage ride-through process of new energy units, the extension time is generally set to 3-5 seconds to ensure that the amount of disconnection from the grid can be accurately calculated during the duration of the fault impact.

[0045] Step 6: Within the extended holding time range when the power or current surge information flag of the AC / DC fault is 1, calculate the grid disconnection amount of each new energy power plant in real time, and sum the losses of each station in the area as the total loss amount of the area. When the calculated total grid disconnection capacity exceeds the set margin, the system sends a grid disconnection limit alarm message to the power grid dispatch center or relevant operation and maintenance personnel through the communication module. At the same time, it can automatically adjust the operating parameters of relevant equipment or disconnect the generators and loads according to the preset control strategy to reduce the impact of new energy grid disconnection on the power grid.

[0046] In step 1, the transmission section consists of all AC lines that transmit power from new energy power plants, or the transmission section consists of all AC lines that transmit power from new energy power generation areas.

[0047] In step 2, the DC lines are all DC lines in the area where the grid disconnection amount needs to be calculated, and the important AC lines are AC lines that are directly connected to the new energy power plants or the near end of the new energy sources in the area, or AC lines that have a significant impact on the voltage of the area.

[0048] In step 5, the expansion time of the DC fault information is on the order of seconds.

[0049] This invention also provides a real-time calculation system for renewable energy grid disconnection based on AC / DC faults, in conjunction with... Figure 3 As shown, it includes a main station device for calculating the amount of power disconnection, a power acquisition device, and an AC / DC fault discrimination device. The AC / DC fault discrimination device includes an AC / DC fault discrimination module, the line power acquisition device includes a line power acquisition module, and the main station device for calculating the amount of power disconnection includes a real-time calculation module for the amount of power disconnection and a result output and alarm module. These will be described in detail below.

[0050] The AC / DC fault detection module uses a high-performance signal acquisition and processing chip, which is connected to voltage and current transformers deployed on DC and AC lines via optical fiber or cable. It collects voltage and current data of the lines in real time and uses the built-in fault detection algorithm to analyze the collected data in real time. Once a fault is detected, fault information is immediately generated and transmitted to the offline quantity calculation master station device.

[0051] The line power acquisition module is also connected to the monitoring equipment of each transmission line of the new energy power plant or the new energy power generation area through a dedicated communication line. It collects three-phase voltage and current data in real time according to the set sampling frequency, quickly calculates the power of each transmission line, and sends the power data to the grid disconnection calculation module in a timely manner.

[0052] The real-time grid disconnection calculation module receives AC / DC fault information from the fault information receiving module and power data from the line power acquisition module. After receiving the fault flag change signal, it quickly retrieves the power data before the fault and the current real-time power data, and calculates the new energy grid disconnection amount according to the above grid disconnection calculation method.

[0053] In a preferred embodiment of the present invention, the real-time grid disconnection calculation module also calculates the total grid disconnection capacity of the new energy power plant or new energy power generation area within the fault flag extension holding time; and sets a result output and alarm module connected to the real-time grid disconnection calculation module to display the calculated total grid disconnection capacity result on the monitoring interface in the form of charts, data reports, etc., for easy viewing by operation and maintenance personnel. Simultaneously, this module has a built-in alarm threshold setting function; when the total grid disconnection capacity exceeds the set threshold, alarm information is promptly issued to relevant personnel through audible and visual alarms, SMS notifications, etc.

[0054] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0055] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0058] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0059] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for real-time calculation of renewable energy grid disconnection based on AC / DC faults, characterized in that: include, Obtain the operating status of DC and important AC lines in new energy power plants or new energy power generation areas, and identify AC and DC faults; When determining that an AC or DC fault has occurred, the power of the outgoing line section before the fault and the power of the current outgoing line section are obtained respectively. The amount of new energy source disconnected from the grid is obtained by comparing the sum of the outgoing line power before the fault with the sum of the current outgoing line power.

2. The method as described in claim 1, characterized in that: To obtain the operating status of DC and important AC lines in new energy power plants or new energy power generation areas, and to identify AC / DC faults, including... Identify the DC and important AC lines in new energy power plants or new energy power generation areas; among them, AC lines that are directly connected to the near end of new energy sources in new energy power plants or new energy power generation areas or have a significant impact on the voltage of the area are designated as important AC lines. The voltage and current data of the DC and important AC lines are collected in real time, and the AC / DC fault is determined based on the voltage and current data.

3. The method as described in claim 1, characterized in that: Obtain the power of the outgoing line section, including, Determine the transmission section of the new energy plant or new energy power generation area; Real-time acquisition of three-phase voltage and current data for each return transmission line at the sending section; Based on the three-phase voltage and current data, the power of each transmission line is obtained; Based on the power of each transmission line, the outgoing line cross-sectional power is obtained.

4. The method as described in claim 3, characterized in that: The transmission section consists of all AC lines for power transmission from new energy power plants or all AC lines for power transmission from new energy power generation areas.

5. The method as described in claim 1, characterized in that: The amount of new energy power disconnected from the grid is obtained based on the difference between the sum of the outgoing line cross-section power before the fault and the sum of the current outgoing line cross-section power, including: Get the outgoing line cross-sectional power at a certain point before the fault, and get the current real-time outgoing line cross-sectional power. The difference between the sum of the outgoing line section power and the sum of the outgoing line section power in the current real-time period before the fault is the amount of new energy disconnected from the grid.

6. The method as described in claim 1, characterized in that: It also includes, When an AC / DC fault is detected, the power or current change information flag of the AC / DC fault is changed from 0 to 1, and the widening and holding time of the flag is determined. During the duration of the widening and holding of the flag bit, obtain the total offline capacity; The total disconnection capacity is compared with a set margin. When the total disconnection capacity exceeds the set margin, an alarm for exceeding the disconnection limit is issued or control measures are taken to reduce the impact on the power grid.

7. The method as described in claim 6, characterized in that: The total off-grid capacity refers to the sum of the off-grid amounts of all new energy power plants or the off-grid amount of the transmission section of the new energy power generation area.

8. A real-time calculation system for renewable energy grid disconnection based on AC / DC faults, characterized in that: include, The AC / DC fault detection module is configured to acquire the operating status of DC and important AC lines in new energy power plants or new energy power generation areas, and to detect AC / DC faults. The line power acquisition module is configured to, upon determining that an AC / DC fault has occurred, acquire the power of the outgoing line section before the fault and the sum of the power of the current outgoing line section; and, The real-time grid disconnection calculation module is configured to obtain the amount of new energy disconnected from the grid based on the difference between the sum of the outgoing line section power before the fault and the sum of the current outgoing line section power.

9. The system as described in claim 8, characterized in that: When the AC / DC fault detection module determines that an AC / DC fault has occurred, it changes the power or current change information flag of the AC / DC fault from 0 to 1 and determines the widening and holding time of the flag. The real-time calculation module for the amount of data removed from the network obtains the total amount of data removed from the network during the time the flag is stretched and held. It also includes, The output and alarm module is configured to display the total offline capacity and to issue an alarm message when the offline capacity exceeds a set margin.

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