Regional protection control method applied to converter and synchronous machine power supply project

Abstract

A regional protection control method applied to a converter + synchronous machine power supply project comprises the steps that (1) an equipment layer comprises IED equipment of a regional power grid transformer substation, a synchronous machine power plant and a converter plant station, and the IED equipment comprises a protection device, a stability device, a PCS / inverter control device and an information conversion device; (2) a station domain layer: the station domain layer comprises station domain layer hosts arranged in a transformer substation, a new energy station and a power plant, and the station domain layer hosts receive electrical quantity and logic quantity information of the whole station in a centralized manner; and (3) a region layer: a region control master station is arranged, the region control master station is in communication connection with the station domain layer, and the region layer is responsible for concentration and analysis of important node information of the whole region. According to the invention, the capability of the protection device for judging the specific fault component of the converter power electronic equipment is enhanced, the response capability of the protection device to the fault is improved, and after the fault is removed, the occurrence and development of the interlocking fault are effectively inhibited through rapid adjustment and cooperation of the power electronic equipment.

Description

Technical Field

[0001] The invention relates to a regional protection control method applied to a converter+synchronous machine power supply project. Background Art

[0002] With the development of new power systems, energy sources and users tend to be diversified. Compared with traditional regional power grids, the types of energy have increased from thermal power to thermal power + photovoltaic + wind power + energy storage. The core component model of the power supply has been updated from synchronous machine to "synchronous machine + converter". Due to the addition of energy storage and electric vehicle charging and discharging V2G models, the load has also changed from a single load characteristic to a bidirectional characteristic. The topological structure and power supply characteristics of the entire regional power grid are in a state of changing with time and space. Due to the uncertainty of system characteristics, the protection control method based on set rules and fixed values ​​for action control is not adaptable enough when facing complex power networks and fault conditions. Summary of the invention

[0003] The technical problem to be solved by the invention is: how to solve the problem of insufficient adaptability in complex power networks and fault conditions, and to provide a regional protection control method applied to converter + synchronous machine power supply projects.

[0004] The technical solution of the present invention is specifically as follows: A regional protection control method applied to a converter + synchronous machine power supply project adopts a regional protection control device system architecture, which includes three layers: regional layer, station layer, and device layer: (1) Equipment layer: including IED equipment of regional power grid substations, synchronous electromechanical plants and converter plants. The IED equipment includes protection devices, stability devices, PCS / inverter control devices and information conversion devices. These IED equipment provide physical signal interfaces, communication interfaces and execution terminals, and collect electrical quantity and status quantity information from transformers, busbars, converters and various outgoing lines, and transmit the collected information to the station domain layer. (2) Station domain layer: including station domain layer hosts set up in substations, new energy stations, and power plants. The station domain layer hosts centrally receive the electrical and logical information of the entire station. The hosts of each plant and station form a distributed system to achieve information fusion and fault location, isolation, operation status reversal, and IED operation value calculation within the station domain; and send key information in the distributed blockchain to the regional layer, accept the master station command, and issue execution information; (3) Regional layer: A regional control master station is set up, which is connected to the station domain layer. The regional layer is responsible for the centralization and analysis of important node information in the entire region. The regional control master station collects information processed and integrated by the station domain layer host of each plant and station in the station domain layer, mines deeper information of the power grid, and completes various control functions that require centralized decision-making.

[0005] In the station domain layer, a) the station domain host in each station communicates with the station domain host of other plants and stations. The plant and the adjacent plant exchange information in a distributed peer-to-peer manner through blockchain technology data to achieve fast and accurate control and protection functions; b) The station domain layer host and equipment layer in each station communicate with each other, collect the electrical quantities and control system logic quantities in the station, collect the comprehensive information of the entire station, realize the integration of the protection and control information of the plant station, and issue operation commands to realize the removal of faults within the plant station.

[0006] The plant-level equipment in the blockchain collects the electrical quantity and switch quantity information collected by each IED device in the station, and publishes the information to the blockchain network; at the same time, each block node stores different types of historical fault information and equipment action information related to the node, and publishes it in the blockchain as an experience module to prepare for the system to conduct deep learning through large-scale data training in the future, build efficient modules and store them in the strategy library to quickly resolve complex chain failures.

[0007] The information in the blockchain mainly includes: (3.1) Block electrical quantities: sudden changes in current, voltage, and frequency on each side of the busbar / line / main transformer / unit within each block; sudden changes in power, direction, and impedance of lines within the block; power angle of block nodes; (3.2) Block switch quantity: location information of relevant circuit breakers in each block, protection switching information; unit switching information; (3.3) Block IED information: operating models, parameters and current operating values ​​of all IEDs in each block; (3.4) Equipment association: logical association information between equipment and lines; (3.5) Fault information: fault type, electrical quantity characteristics at the time of fault, and primary and secondary equipment operation information.

[0008] Each block node has complete information in the area in real time, and the blockchain station domain protects the data flow in the following steps: (4.1) Extract highly relevant data from the information, such as the impedance of upstream and downstream lines, the main connection of adjacent substations, and the operation mode of the main transformer; (4.2) Analyze and process the data, infer the relevant power link topology, and obtain the characteristic values ​​related to the node; (4.3) Match the topology diagram with the operation mode in the runtime library; (4.4) Compare and match the characteristic value with the IED operation model in the IED model library to determine the IED operation value under a specific operation mode; (4.5) Sending corresponding IED operation values ​​and update instructions to each IED device in the block node; (4.6) According to the electrical quantity and switch quantity information, match the strategy library to achieve accurate detection and location of the fault type, and issue action instructions to the IED device in the block node; (4.7) Accept the power flow control command from the regional system protection master station, execute emergency power / load regulation, or reverse the operating status, and return the execution results to the blockchain.

[0009] The beneficial effects of the present invention are as follows: the present invention enhances the protection device's ability to judge fault components unique to converter power electronic equipment, improves the protection device's ability to respond to faults, and effectively suppresses the occurrence and development of interlocking faults through rapid adjustment and coordinated cooperation of power electronic equipment after the fault is removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the schematic diagram of regional protection control; Figure 2 This is the equipment architecture diagram of the regional protection control system; Figure 3 It is a data structure diagram of the blockchain area protection station domain layer; Figure 4 Protect data flow for blockchain domains; Figure 5 It is the networking mode of the device nodes at the station domain layer. DETAILED DESCRIPTION

[0011] 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.

[0012] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0013] like Figure 1 As shown in the figure, a regional protection control method applied to converter + synchronous machine power supply projects combines spatial scale and time scale, adopts a hierarchical distributed structure, and performs precise control of multi-dimensional objectives such as fault location, fault isolation, power flow optimization, and power supply restoration through vertical and horizontal system coordination.

[0014] The regional protection control equipment architecture adopted by the present invention is as follows: Figure 1 As shown in the figure, the regional power grid panoramic data information is used, and the multi-principle fault identification method is used to integrate the spatial scale and time scale power grid operation information, and based on the blockchain data structure, the coordination of protection devices is achieved. At the spatial scale level, the entire system contains three layers: regional layer, station layer, and equipment layer.

[0015] (1) Equipment layer: including IED equipment of regional power grid substations, synchronous electromechanical plants and converter plants, including protection devices, stability devices, PCS / inverter control devices, information conversion devices, etc. These IED equipment provide physical signal interfaces, communication interfaces and execution terminals, and collect electrical quantity and status quantity information from transformers, busbars, converters and various outgoing lines, and transmit the collected information to the station domain layer to realize data sharing.

[0016] (2) Station domain layer: includes station domain layer hosts installed in substations, new energy stations, and power plants. The station domain layer hosts are station-domain centralized and inter-station distributed protection control systems. The station domain layer hosts centrally receive the electrical and logical quantity information of the entire station. The hosts of each plant and station constitute a distributed system, and exchange logical quantities, electrical quantities and other information between stations. Realize information fusion and control such as fault location, isolation, operating status reversal, and IED operating value within the station domain; and send key information in the distributed blockchain to the regional layer, accept the master station command, and issue execution information; a) Protection information collection within the plant and station utilizes digital network communication technology and is based on unified protocols to achieve information exchange.

[0017] b) The station domain layer host in each station can communicate with the station domain layer hosts of other plants and stations. The plant and the adjacent plant stations exchange information in a distributed and peer-to-peer manner through blockchain technology data to achieve fast and accurate control and protection functions.

[0018] c) The station domain layer host in each station can communicate with the equipment layer, collect electrical quantities and control system logic quantities in the station, collect comprehensive information of the entire station, realize the integration of protection and control information of the plant station, and issue operation commands when necessary to eliminate faults within the plant station.

[0019] (3) Regional layer: There is a regional control master station, which is connected to the station layer. The regional layer is responsible for the centralization and analysis of important node information in the entire region. The regional control master station faces the regional power grid of synchronous machines + converters, collects information processed and integrated by the station layer host of each plant in the station layer, mines deeper information of the power grid, completes various control functions that require centralized decision-making, and focuses on safety, stability and coordinated control. The specific work is as follows: a) Realize fault judgment and isolation between stations to minimize the scope of accidents: collect fault information such as fault time, type, and location from relay protection of each plant and station, realize the integration and coordination of relay protection devices and safe and stable control systems, and when the regional control master station completes the decision on machine cutting and load shedding control in the region, it can complete rapid power adjustment and accurate machine cutting and load shedding control through coordination with the control of the station domain distributed host. After the fault is isolated, power supply is restored according to the principle of user priority to reduce power outage time and enhance customer satisfaction. Realize regional standby automatic switching and regional reclosing functions to solve the interactive coordination problem of reclosing and standby automatic switching in multi-energy regional power grids.

[0020] b) After the regional layer master station makes a centralized decision, it communicates with the corresponding station layer equipment, and the station layer equipment issues actual operation commands.

[0021] c) Adjust the working status of various power sources and optimize the uniform distribution of electric energy in the area.

[0022] At the time scale level, the entire system takes advantage of the decision-making advantages of each level, and through the coordination of the timelines of each device, it realizes accurate fault control and optimization of execution rounds, improving the sensitivity and reliability of IED equipment. First, the system shares information between the devices at the station domain layer according to the changes in the system operation mode, calculates the impedance changes of related system nodes, and realizes the mutual coordination of the operating time values ​​of IED equipment; secondly, the regional layer decides the action sequence of each station domain layer after the fault according to the operation information of key nodes, and adjusts the operation status of each power node when optimizing the power flow.

[0023] In the station domain layer, the present invention combines the decentralized data structure of blockchain to construct a distributed control architecture, which can realize regional protection information interaction and real-time sharing, control protection coordination, and judge the consistency of multi-logic quantity information on the basis of information fusion. It uses the electrical quantity of the whole process to identify fault characteristics, solve the accuracy of the backup protection judgment of the protection device, improve the reliability of the protection device, and realize emergency control under power imbalance at the sending and receiving ends of the system and emergency control of system energy imbalance when the power grid suffers serious faults.

[0024] The distributed control architecture of the station domain layer adopts a decentralized blockchain. In the blockchain network structure, each node is equal, without a master-slave distinction, and each node stores all the data in the network. By utilizing the immutability, transparency, and distributed characteristics of the blockchain, while maximizing the information sharing of each node, information security is ensured, so that the entire system can publish information in real time when the topology changes.

[0025] The present invention is based on the distributed consensus mechanism of blockchain, constructs the station-field plant-station layer subsystem strategy of the distributed regional system protection system, uses the plant-field layer station-field protection equipment in a certain range of regional power grids as blockchain nodes, and each block plant-station node forms a blockchain network distributed system according to the regional network topology structure. This system does not rely on the central control system, has high robustness and reliability, and can effectively deal with malicious attacks and system failures. Each node in the blockchain of the present invention automatically adapts to the changing state of power supply and load characteristics, uses a large amount of all-round relevant data, performs intelligent analysis and strategy selection, accurately locates, reduces the risk of false operation and refusal to operate, thereby quickly and correctly realizing fault isolation, and improving the reliability and accuracy of the entire system.

[0026] The plant-level equipment in the blockchain collects the electrical quantity and switch quantity information collected by each IED device in the station, and publishes the information to the blockchain network, so that the information can be shared transparently; at the same time, each block node stores different types of historical fault information and equipment action information related to the node, and publishes it in the blockchain as an experience module to prepare for the system to conduct deep learning through large-scale data training in the future, build efficient modules and store them in the strategy library to quickly resolve complex chain failures.

[0027] The blockchain regional protection station domain layer data structure is shown in Figure 3 , the information in the blockchain mainly includes: (3.1) Block electrical quantities: Sudden changes in current, voltage and frequency on each side of the busbar / line / main transformer / unit in each block; sudden changes in power, direction and impedance of the lines in the block; power angle of the block nodes.

[0028] (3.2) Block switch quantity: relevant circuit breaker position information and protection switching information in each block; unit switching information.

[0029] (3.3) Block IED information: operating models, parameters and current operating values ​​of all IEDs in each block, such as control words, set values, etc.

[0030] (3.4) Equipment association: logical association information between devices and lines.

[0031] (3.5) Fault information: fault type, electrical quantity characteristics at the time of fault, and primary and secondary equipment operation information.

[0032] Each block node has real-time access to complete information in the region. The blockchain station domain protection data flow diagram is shown in Figure 4 , including the following steps: (4.1) Extract highly relevant data from the information, such as the impedance of upstream and downstream lines, the main connection of adjacent substations, and the operation mode of the main transformer; (4.2) Analyze and process the data, infer the relevant power link topology, and obtain the characteristic values ​​related to the node; (4.3) Match the topology diagram with the operation mode in the runtime library; (4.4) Compare and match the characteristic value with the IED operation model in the IED model library to determine the IED operation value under a specific operation mode; (4.5) Sending corresponding IED operation values ​​and update instructions to each IED device in the block node; (4.6) According to the electrical quantity and switch quantity information, match the strategy library to achieve accurate detection and location of the fault type, and issue action instructions to the IED device in the block node; (4.7) Receive power flow control commands from the regional system protection master station. Execute emergency power / load regulation or reverse operation status. Return the execution results to the blockchain.

[0033] The node networking mode of the station domain layer device is as follows: The nodes in the plant-level equipment network are networked in a P2P manner, and the communication mode is optical communication, which realizes high-speed data transmission and sharing. The communication between nodes does not rely on the upper-level regional layer equipment, but realizes data exchange and resource sharing through direct communication of the network; each node has complete decision-making functions, and there is no master-slave distinction. The networking diagram is shown in Figure 5 .

[0034] The above-described embodiments are only preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several changes and improvements may be made without departing from the overall concept of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A regional protection control method applied to a converter + synchronous machine power supply project, characterized in that: The regional protection control equipment system architecture adopted includes three layers: regional layer, station layer and equipment layer: (1) Equipment layer: including IED equipment of regional power grid substations, synchronous electromechanical plants and converter plants. The IED equipment includes protection devices, stability devices, PCS / inverter control devices and information conversion devices. These IED equipment provide physical signal interfaces, communication interfaces and execution terminals, and collect electrical quantity and status quantity information from transformers, busbars, converters and various outgoing lines, and transmit the collected information to the station domain layer. (2) Station domain layer: It includes station domain layer hosts installed in substations, new energy stations, and power plants. The station domain layer hosts centrally receive the electrical and logical information of the entire station. The hosts of each plant and station form a distributed system to achieve information fusion and fault location, isolation, operation status reversal, and IED operation value calculation within the station domain; And send key information in the distributed blockchain to the regional layer, accept the main station command, and send execution information; (3) Regional layer: A regional control master station is set up, which is connected to the station domain layer. The regional layer is responsible for the centralization and analysis of important node information in the entire region. The regional control master station collects information processed and integrated by the station domain layer host of each plant and station in the station domain layer, mines deeper information of the power grid, and completes various control functions that require centralized decision-making.

2. A method for regional protection control applied to a converter + synchronous machine power supply project according to claim 1, characterized in that: At the site level, a) The station domain host in each station communicates with the station domain host of other plants and stations. The plant and the adjacent plants exchange information in a distributed peer-to-peer manner through blockchain technology data to achieve fast and accurate control and protection functions; b) The station domain layer host and equipment layer in each station communicate with each other, collect the electrical quantities and control system logic quantities in the station, collect the comprehensive information of the entire station, realize the integration of the protection and control information of the plant station, and issue operation commands to realize the removal of faults within the plant station.

3. A method for regional protection control applied to a converter + synchronous machine power supply project according to claim 2, characterized in that: The plant-level equipment in the blockchain collects the electrical quantity and switch quantity information collected by each IED device in the station, and publishes the information to the blockchain network; at the same time, each block node stores different types of historical fault information and equipment action information related to the node, and publishes it in the blockchain as an experience module to prepare for the system to conduct deep learning through large-scale data training in the future, build efficient modules and store them in the strategy library to quickly resolve complex chain failures.

4. A method for regional protection control applied to a converter + synchronous machine power supply project according to claim 3, characterized in that: The information in the blockchain mainly includes: (3.1) Block electrical quantities: sudden changes in current, voltage, and frequency on each side of the busbar / line / main transformer / unit within each block; sudden changes in power, direction, and impedance of the lines within the block; Block node power angle; (3.2) Block switch quantity: location information of relevant circuit breakers in each block, protection switching information; unit switching information; (3.3) Block IED information: operating models, parameters and current operating values ​​of all IEDs in each block; (3.4) Equipment association: logical association information between equipment and lines; (3.5) Fault information: fault type, electrical quantity characteristics at the time of fault, and primary and secondary equipment operation information.

5. The method for regional protection control applied to converter + synchronous machine power supply project according to claim 3 is characterized in that: Each block node has complete information in the area in real time, and the blockchain station domain protects the data flow in the following steps: (4.1) Extract highly relevant data from the information, such as the impedance of upstream and downstream lines, the main connection of adjacent substations, and the operation mode of the main transformer; (4.2) Analyze and process the data, infer the relevant power link topology, and obtain the characteristic values ​​related to the node; (4.3) Match the topology diagram with the operation mode in the runtime library; (4.4) Compare and match the characteristic value with the IED operation model in the IED model library to determine the IED operation value under a specific operation mode; (4.5) Sending corresponding IED operation values ​​and update instructions to each IED device in the block node; (4.6) According to the electrical quantity and switch quantity information, match the strategy library to achieve accurate detection and location of the fault type, and issue action instructions to the IED device in the block node; (4.7) Accept the power flow control command from the regional system protection master station, execute emergency power / load regulation, or reverse the operating status, and return the execution results to the blockchain.

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