Electric power low-frequency load shedding system

Abstract

The invention relates to an electric power low-frequency load shedding system in the field of electric power systems, which comprises a terminal system and a plurality of partition systems, the terminal system comprises a data processing module, a low-frequency load shedding module, a monitoring module, a data storage module, a user management module and a data transmission module, and the data processing module is used for calculating a total load shedding amount, selecting a load shedding strategy and processing and recovering a load. The low-frequency load shedding module identifies a line and executes a load shedding strategy; the monitoring module monitors power grid frequency and user side load information; the data storage module stores historical data, user information and plans; the user management module manages user priorities; and the load regulation and control executes a load shedding and recovery instruction, calls a load shedding device for load shedding, acquires monitoring data of a user side through an information acquisition module, and is connected with an intelligent electric meter, so that low-frequency load shedding and intelligent partition power utilization management technologies are combined, and accurate monitoring and quick response of the power grid frequency are realized.

Description

Technical Field

[0001] The present invention relates to an electric power low-frequency load reduction system, and in particular to an electric power low-frequency load reduction system applied in the field of electric power systems. Background Art

[0002] The power underfrequency load shedding system is a protection measure for the stability of the power system. Its main purpose is to automatically cut off some non-critical loads when the power system frequency drops to a certain level to prevent the system frequency from further dropping, thereby avoiding large-scale power outages and equipment damage. The underfrequency load shedding system plays a vital role in the power system, especially when there is an imbalance between power generation and load.

[0003] In order to solve the problem of low-frequency load reduction system of electric power, a low-frequency load reduction system in the market adopts the design of low-frequency relay and has a certain market share.

[0004] The specification of Chinese invention patent CN106684891B discloses a method and system for high-frequency cutting of power systems, the method comprising calculating the upper limit of the cutting amount of each round of high-frequency cutting of the power system, and determining the cutting amount of each round of high-frequency cutting according to the upper limit of the cutting amount. Compared with the prior art, the method and system for high-frequency cutting of power systems provided by the present invention can prevent the system frequency from dropping too much due to cutting off too many generators, thereby causing the low-frequency load shedding device of the power system to malfunction and cause load loss The existing power low-frequency load shedding system mostly performs batch recovery when the load is restored after load shedding. When a large number of loads are restored quickly, the system may experience power shortage again because the power generation capacity cannot keep up in time, causing the system frequency to drop again. In addition, the existing power low-frequency load shedding system is not easy to perform effective load recovery management according to the importance of different users when the load is restored in a complex manner after load shedding. When the idle load is insufficient, it is not easy to give priority to the load recovery of important users. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that when the existing low-frequency load shedding system restores the load after load shedding, it is mostly a batch recovery. When a large number of loads are quickly recovered, the system may have a power shortage again because the power generation capacity cannot keep up in time, causing the system frequency to drop again. In addition, when the existing low-frequency load shedding system recovers in a complex manner after load shedding, it is not easy to effectively manage the load recovery according to the importance of different users. When the idle load is insufficient, it is not easy to give priority to the load recovery of important users.

[0006] In order to solve the above problems, the present invention provides a power low-frequency load reduction system, including a terminal system and multiple partition systems, wherein multiple user terminals are arranged in the partition system, and the terminal system includes: A data processing module is used to calculate the total load shedding amount according to the collected data, select a load shedding strategy according to the total load shedding amount, and process a load restoration request; The low-frequency load shedding module identifies the line properties and executes the preset load shedding strategy; the load shedding strategy includes the regional priority load shedding strategy and the user priority load shedding strategy; The monitoring module is used to monitor the grid frequency and the load information of each user end. The load information includes: real-time load status, load shedding after action and idle load; Data storage module, used to store historical monitoring data, user information and load shedding strategy plan information; The user management module is used to manage user priorities. Users are divided into different priority users from low to high; A data transmission module is used to transmit the monitoring data of each partition system to the terminal system. The monitoring data includes: user requests and instruction sending. The data transmission module is provided with a request channel and a data transmission channel; The partition system includes: A load regulation module is used to execute load reduction instructions and load recovery instructions. A load reduction device is connected to the load regulation module. When the load regulation module executes the load reduction instruction, the load reduction device is called to reduce the load of each device group at the user end in turn. The information collection module is used to collect monitoring data of each user terminal in the partition, and the information collection module is connected to a smart meter.

[0007] In the above-mentioned power low-frequency load reduction system, low-frequency load reduction and intelligent zoning power management technology are combined to achieve accurate monitoring and rapid response of the power grid frequency.

[0008] As a further improvement of the present application, the request channel includes a priority channel and a normal channel; The priority channel sorts requests according to user priority. The ordinary channel includes the sequential channel and the leaky bucket channel. The request channel sets the admission level of different channels according to the recovery load strategy.

[0009] As a further improvement of the present application, when the user end sends a user load recovery request, it sends device group recovery requests in sequence, and sends a new request after the previous device group is recovered.

[0010] As a further improvement of the present application, after the user end sends a load recovery request, the information collection module counts the total recovery load demand of users at all levels and sends it to the terminal system. The data processing module chooses to open a priority channel or a normal channel based on the total recovery load demand of users at all levels.

[0011] As another improvement of the present application, a region division module is provided in the system terminal, and the region division module is used to divide the priority of each partition.

[0012] As another improved supplement to the present application, the regional priority load reduction strategy specifically includes: selecting the load reduction area according to the required load reduction amount, and giving priority to low-priority areas for load reduction; after selecting the load reduction area, selecting the user end in turn according to the user priority in the area to cut load.

[0013] As another improved supplement of the present application, the user priority load shedding strategy specifically includes: grouping and sorting users of different priorities in each partition; when shedding load, selecting user terminals in each priority group in turn for load shedding.

[0014] As another improvement of the present application, when executing the load reduction strategy, when selecting multiple user terminals of the same priority for load shedding, a suitable optimal user terminal is selected for load shedding according to a load optimal shedding algorithm.

[0015] To sum up, this solution realizes the zoning and layered load shedding mode, and supports flexible zoning and layered load shedding modes. When load shedding demand occurs, the system first analyzes the zoning situation and divides the power grid into several management areas. In the zoning load shedding mode, the partitions that perform non-essential tasks are given priority for unified management, and the load is gradually reduced according to the user classification strategy. The layered load shedding is further refined to the equipment level to ensure that the load shedding operation is more accurate, and the accurate monitoring and rapid response of the power grid frequency are realized. Through the zoning and layered load shedding strategy, the accuracy, flexibility and safety of operations during load shedding and load recovery are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a system block diagram of the first and second implementation modes of this application; Figure 2 This is the load shedding working logic diagram of the first and second implementation modes of this application; Figure 3 This is a logic diagram for executing the load shedding strategy in the first and second implementation modes of this application; Figure 4 This is a schematic diagram of the load recovery steps of the second implementation mode of the present application. DETAILED DESCRIPTION

[0017] The following describes two implementation modes of the present application in detail with reference to the accompanying drawings.

[0018] The first implementation method: Figure 1-3 It is shown that a power low-frequency load reduction system includes a terminal system and multiple partition systems, wherein multiple user terminals are arranged in the partition system, and the terminal system includes: A data processing module is used to calculate the total load shedding amount according to the collected data, select a load shedding strategy according to the total load shedding amount, and process a load restoration request; The low-frequency load shedding module identifies the nature of the line and executes the preset load shedding strategy; the load shedding strategy includes the regional priority load shedding strategy and the user priority load shedding strategy; the user priority load shedding strategy specifically includes: grouping and sorting users of different priorities in each partition; when shedding load, the user terminals in each priority group are selected in turn for load shedding.

[0019] The monitoring module is used to monitor the grid frequency and the load information of each user end. The load information includes: real-time load status, load shedding after action and idle load; Data storage module, used to store historical monitoring data, user information and load shedding strategy plan information; The user management module is used to manage user priorities. Users are divided into different priority users from low to high.

[0020] This terminal system uses a high-precision detection module to monitor the grid frequency in real time. Once the frequency is lower than the preset threshold and lasts for more than the set time, the system will automatically start the load reduction process. Through the preset algorithm and model, the required load reduction is calculated according to the degree and speed of frequency reduction, and then the load reduction work is carried out according to the preset load reduction strategy.

[0021] A data transmission module is used to transmit the monitoring data of each partition system to the terminal system. The monitoring data includes: user requests and instruction sending. The data transmission module is provided with a request channel and a data transmission channel; The request channel includes a priority channel and a normal channel; the priority channel sorts requests according to user priority, the normal channel includes a sequential channel and a leaky bucket channel, and the request channel sets the admission level of different channels according to the recovery load strategy.

[0022] The partition system includes: A load regulation module is used to execute load reduction instructions and load recovery instructions. A load reduction device is connected to the load regulation module. When the load regulation module executes the load reduction instruction, the load reduction device is called to reduce the load of each device group at the user end in turn. The information collection module is used to collect monitoring data of each user terminal in the partition, and the information collection module is connected to a smart meter.

[0023] When the user sends a user load recovery request, it sends device group recovery requests in sequence, and sends a new request after the previous device group is recovered; After the user sends a load recovery request, the information collection module counts the total recovery load demand of users at all levels and sends it to the terminal system. The data processing module chooses to open a priority channel or a common channel based on the total recovery load demand of users at all levels. When the system is working, the detection module monitors the grid frequency. When the frequency is lower than the set value and lasts for more than the set time, the load reduction amount is calculated, and the load reduction is carried out according to the preset load reduction strategy. Specifically, according to the degree and speed of the grid frequency drop, the low-frequency load reduction device calculates the load amount to be removed, which is implemented by a technician in this field, using a suitable algorithm and model in the existing technology. In this embodiment, when reducing the load, the low-frequency load reduction module executes the user priority load reduction strategy and sends a load reduction instruction to the load regulation module. When the partitioned power consumption management module reduces the load, it reduces the load of the device groups on the corresponding user end in turn according to the partition user priority. After all the load-reducible device groups on a user end are reduced, the next user end is reduced until the grid frequency returns to the normal range.

[0024] Furthermore, when shedding load, for multiple user terminals of the same priority, a suitable optimal user terminal is selected for load shedding according to the load optimal shedding algorithm; the optimal shedding algorithm in this scheme is a prior art and does not fall within the protection scope of this scheme. A person skilled in the art shall set a suitable optimal shedding algorithm in the prior art and load it into the system to ensure that the system can select the optimal user terminal for shedding load from multiple user terminals when shedding load; After the grid frequency is restored, the idle load is monitored and then the request channel is opened; the user whose load is reduced sends a request for the equipment group to restore the load according to the demand; After the user sends a load recovery request, the information collection module counts the total recovery load demand of users at all levels and sends it to the terminal system. The data processing module chooses to open a priority channel or a common channel based on the total recovery load demand of users at all levels. Specifically, the data processing module calculates whether the real-time idle load can meet the total recovery load demand of users at all levels. If it can be met, all request channels are opened; if not, only the priority channel is opened for request processing, and then the idle load can meet the total recovery load demand of several levels of users, and the corresponding access level of the priority channel is set, so that the priority channel only transmits priority user requests above the set priority level; During the load recovery process, after the user request transmitted by the request channel is processed by the data processing module, a load recovery instruction is sent, so that the load control module executes the load recovery instruction to restore the load to the corresponding user; during each recovery process, various system parameters such as voltage, current, power factor, frequency, etc. are continuously monitored to ensure that these parameters fluctuate within a safe range to determine whether the system is stable; If the parameters are abnormal, the load recovery is stopped and the recovered load is reduced. At the same time, the user is marked and the request is recorded before processing the next user request; When the recorded requests are greater than the set number, the request channel is closed, the system alarms, and the preset technicians are notified to check the master control system and marked users.

[0025] Second implementation method Figure 3-4 , wherein the components identical or corresponding to those in the first embodiment are designated by the corresponding reference numerals in the first embodiment, and for the sake of simplicity, only the differences from the first embodiment are described below. The second embodiment differs from the first embodiment in that: A region division module is provided in the system terminal, and the region division module is used to divide the priority of each partition.

[0026] The regional priority load reduction strategy specifically includes: selecting the load reduction area according to the required load reduction amount, giving priority to low-priority areas for load reduction; after selecting the load reduction area, the user end is selected in turn according to the user priority in the area to cut load.

[0027] This solution can reduce load by zoning. When load reduction is needed, the zoning is divided into groups according to the analysis of the zoning situation. When the regional priority load reduction strategy is used, the same-level zones are selected in turn and load reduction operations are performed uniformly. When load reduction is performed, the load-reducing devices of each graded user are reduced in turn according to the user classification. Optionally, when shedding load, for multiple user terminals of the same priority level, a suitable optimal user terminal is selected for load shedding according to the load optimal shedding algorithm; after all load shedding equipment groups on a user terminal are shedding load, another user terminal is selected for load shedding until the grid frequency returns to a normal range; This implementation method implements a hierarchical load reduction strategy within the partition. According to the priority setting of the partition users, low-priority users are preferentially reduced to ensure that critical loads are not affected. At the same time, the load reduction operation within the partition follows the principle of selecting the best load reduction users in turn to avoid power grid fluctuations caused by concentrated load reduction.

[0028] To sum up, this solution realizes the partition and layered load shedding mode, and supports flexible partition and layered load shedding modes. When load shedding demand occurs, the system first analyzes the partition situation and divides the power grid into several management areas. In the partition load shedding mode, the partitions that perform non-essential tasks are given priority for unified management, and the load is gradually reduced according to the user classification strategy. The layered load shedding is further refined to the equipment level to ensure that the load shedding operation is more accurate.

[0029] This solution combines low-frequency load reduction with intelligent zoning power management technology to achieve accurate monitoring and rapid response of grid frequency. Through zoning and graded load reduction strategies, it effectively improves the accuracy, flexibility and safety of load reduction and load restoration operations.

[0030] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. An electric power low-frequency load reduction system, comprising a terminal system and a plurality of partition systems, wherein a plurality of user terminals are arranged in the partition system, characterized in that: The terminal system comprises: A data processing module is used to calculate the total load shedding amount according to the collected data, select a load shedding strategy according to the total load shedding amount, and process a load restoration request; An underfrequency load shedding module identifies the line properties and executes a preset load shedding strategy; the load shedding strategy includes a regional priority load shedding strategy and a user priority load shedding strategy; A monitoring module is used to monitor the power grid frequency and the load information of each user end, wherein the load information includes: real-time load status, load shedding after action and idle load; Data storage module, used to store historical monitoring data, user information and load shedding strategy plan information; The user management module is used to manage user priorities, and users are divided into users with different priorities from low to high; The partition system comprises: A data transmission module, used to transmit the monitoring data of each partition system to the terminal system, wherein the monitoring data includes user requests and instruction sending, and the data transmission module is provided with a request channel and a data transmission channel; A load regulation module is used to execute load reduction instructions and load recovery instructions. The load regulation module is connected to a load reduction device. When the load regulation module executes the load reduction instruction, the load reduction device is called to reduce the load of each device group at the user end in turn. The information collection module is used to collect monitoring data of each user terminal in the partition, and the information collection module is connected to a smart meter.

2. The power low-frequency load reduction system according to claim 1, characterized in that: The request channel includes a priority channel and a normal channel; The priority channel sorts requests according to user priority, the common channel includes a sequential channel and a leaky bucket channel, and the request channel sets admission levels of different channels according to a recovery load strategy.

3. The power low-frequency load reduction system according to claim 1, characterized in that: When the user terminal sends a user load recovery request, it sends a load recovery request for the device group whose load is reduced from back to front in the order in which the device group is reduced, and sends a new load recovery request after the previous device group recovers the load, so as to realize unified batching of multiple user terminals.

4. The power low-frequency load reduction system according to claim 1, characterized in that: After the user terminal sends a load recovery request, the information collection module counts the total recovery load demand of users at all levels and sends it to the terminal system. The data processing module chooses to open a priority channel or a normal channel according to the total recovery load demand of users at all levels.

5. The power low-frequency load reduction system according to claim 1, characterized in that: The system terminal is provided with a region division module, and the region division module is used to divide the priority of each partition.

6. The power low-frequency load reduction system according to claim 1, characterized in that: The regional priority load shedding strategy specifically includes: selecting a load shedding area according to the required load shedding amount, and giving priority to low priority areas for load shedding; after selecting the load shedding area, selecting user terminals in turn according to the user priorities in the area to shed the load.

7. The power low-frequency load reduction system according to claim 1, characterized in that: The user priority load shedding strategy specifically includes: grouping and sorting users with different priorities in each partition; when shedding load, selecting user terminals in each priority group in turn for load shedding.

8. The power low-frequency load reduction system according to claim 6 or 7, characterized in that: When executing the load shedding strategy, when selecting load shedding for multiple user terminals of the same priority, a suitable optimal user terminal is selected for load shedding according to the load optimal shedding algorithm.

9. The power low-frequency load reduction system according to claim 1, characterized in that: When the load control module executes the load recovery instruction, it continuously monitors various parameters of the system. If the parameters are abnormal, the load recovery is stopped and the recovered load is reduced. At the same time, the user is marked and the request is recorded. The data processing module then processes the next user request. When the recorded requests are greater than the set number, the request channel is closed and the system alarm is issued.

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