Rapid fault isolation method and device for power network powered by power electronic power supply

Abstract

The invention discloses a rapid fault isolation method and device for a power network powered by a power electronic power supply, and the method comprises the steps: respectively obtaining the grid-connected point voltage values of a plurality of pieces of power electronic power supply equipment at the same preset time when the grid-connected point voltage is abnormal, and sorting the grid-connected point voltage values from small to large; based on the topological structure of the power network, determining the bus corresponding to the minimum voltage value of the grid-connected point as the first bus closest to the fault point of the power network in combination with the sorting result; and locking a power electronic power supply equipment trigger pulse corresponding to the first bus, determining an opposite-end bus connected with the first bus as a second bus according to the grid-connected point voltage value variation before and after locking, and isolating a fault line between the first bus and the second bus. By adopting a multi-point voltage amplitude sorting comparison criterion, the requirements on data synchronization and data precision are relatively low; rapid isolation of internal faults of a renewable energy local power grid or a regional energy autonomous power grid is realized, and a guarantee is provided for continuous power supply of a non-fault region.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid fault detection, and in particular to a method and device for quickly isolating faults in a power network powered by a power electronic power supply. Background Art

[0002] In places where electricity supply is needed, such as islands, pastoral areas, remote mountainous areas, and even highway service areas, agricultural vegetable greenhouses, and livestock breeding bases, there are problems with the extension construction cost of the power grid and the high cost of electricity supply, which can be solved by building a renewable energy local power grid. The renewable energy local area network is an isolated network that can operate independently, reliably, and autonomously, and mostly uses power electronic power supply equipment as a stable power supply. The power network powered by 100% power electronic power supply equipment will gradually become the choice direction of renewable energy local power grids because of its simple and convenient construction and operation management, and its strong favorable characteristics of low carbon and environmental protection. Regional energy autonomous power grids that use weak connections between energy-intensive industrial parks and large power grids will also be developed due to the advantages of low electricity costs and low carbon and environmental protection. However, the power network that is 100% powered by power electronic power sources has adaptability differences with the existing distribution network fault isolation methods supported by traditional power sources that use automation devices. In addition, the differential coordination method or the recloser method has the problem of too long fault isolation time. Centralized feeder automation also has the problems of high cost and long time. These have increased the downtime of power electronic power equipment, increased the power network outage time and the workload of operation and maintenance personnel, and reduced power supply reliability. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a method and device for rapid fault isolation of an electric power network powered by a power electronic power supply. By adopting a multi-point voltage amplitude sorting and comparison criterion, the requirements for data synchronization and data accuracy are relatively low, which can effectively reduce costs; it realizes the rapid isolation of internal faults of a renewable energy local power grid or a regional energy autonomous power grid, and provides a guarantee for continued power supply to non-fault areas, thereby effectively reducing power outage time and reducing the workload of operation and maintenance personnel.

[0004] To solve the above technical problems, a first aspect of an embodiment of the present invention provides a method for rapid fault isolation of a power network powered by a power electronic power supply, wherein the power network includes a plurality of distributed power electronic power supply devices, and the method includes the following steps:

[0005] When the grid connection point voltage is abnormal, respectively obtaining grid connection point voltage values ​​of a plurality of the power electronic power supply devices at the same preset time, and sorting the plurality of grid connection point voltage values ​​from small to large;

[0006] Based on the topological structure of the power network, combined with the sorting result, determine that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network;

[0007] The trigger pulse of the power electronic power supply device corresponding to the first bus is locked, and the opposite bus connected to the first bus is determined to be the second bus according to the voltage value change of the grid connection point before and after locking, and the fault line between the first bus and the second bus is isolated.

[0008] Furthermore, the obtaining of grid-connected point voltage values ​​of a plurality of the power electronic power supply devices at the same time and sorting the plurality of grid-connected point voltage values ​​from small to large includes:

[0009] Acquire a plurality of grid connection point voltage values ​​of each of the power electronic power supply devices within a preset time period;

[0010] Calculating the per unit value of the average value of the grid connection point voltage of each of the power electronic power supply devices during the preset time period;

[0011] The per-unit values ​​of the power electronic power supply devices are sorted from small to large.

[0012] Further, after determining that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the power network fault point in combination with the sorting result, the method includes:

[0013] Acquire a plurality of opposite-end busbars connected to the first busbar;

[0014] Determine whether the average grid connection point voltage of each of the opposite-end busbars and the corresponding busbars connected thereto increases in sequence;

[0015] If yes, determining that the first bus is the bus closest to the fault point of the power network;

[0016] If not, the step of obtaining the grid-connected point voltage values ​​of the plurality of power electronic power supply devices at the same time is performed again.

[0017] Further, the determining that the opposite end busbar connected to the first busbar is the second busbar according to the change in the grid connection point voltage value before and after the blocking includes:

[0018] Respectively obtaining the average voltage of the grid connection point of a plurality of opposite-end buses connected to the first bus after blocking in the preset time period;

[0019] Calculate the average value change of the grid connection point voltage of each of the opposite-end buses before and after blocking;

[0020] The opposite bus with the smallest average voltage change at the grid connection point is selected as the second bus.

[0021] Furthermore, before respectively obtaining the grid connection point voltage values ​​of the plurality of power electronic power supply devices at the same preset time and sorting the plurality of grid connection point voltage values ​​from small to large, it also includes:

[0022] If there is no power electronic power supply equipment on a busbar of the power network, a voltage sampling component is provided on the busbar;

[0023] The grid connection point voltage value of the voltage of the voltage sampling component at the same preset time is obtained.

[0024] Furthermore, each of the power electronic power supply devices and the centralized control system of the power network perform data transmission via GOOSE messages.

[0025] Furthermore, before respectively obtaining the grid connection point voltage values ​​of the plurality of power electronic power supply devices at the same time, the method further includes:

[0026] The centralized control system of the power network and the plurality of power electronic power supply devices are synchronized by IEEE 1588 synchronization, B code synchronization, GOOSE message synchronization, pulse-per-second synchronization or network SNTP synchronization.

[0027] Furthermore, the power network includes: a renewable energy local power grid or a regional energy autonomous power grid.

[0028] Accordingly, a second aspect of an embodiment of the present invention provides a fast fault isolation device for a power network powered by a power electronic power supply, wherein the power network includes a plurality of distributed power electronic power supply devices, and the device includes:

[0029] A voltage detection module, which is used to obtain the grid connection point voltage values ​​of several power electronic power supply devices at the same preset time respectively when the grid connection point voltage is abnormal, and sort the several grid connection point voltage values ​​from small to large;

[0030] A first fault detection module, which is used to determine, based on the topological structure of the power network and in combination with the sorting result, that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network;

[0031] The second fault detection module is used to lock the trigger pulse of the power electronic power supply device corresponding to the first bus, determine that the opposite bus connected to the first bus is the second bus according to the change in the voltage value of the grid connection point before and after locking, and isolate the fault line between the first bus and the second bus.

[0032] Correspondingly, the third aspect of an embodiment of the present invention also provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the above-mentioned smart substation multi-compartment system-level protection function detection method.

[0033] In addition, the fourth aspect of the embodiment of the present invention further provides a computer-readable storage medium on which computer instructions are stored, and when the instructions are executed by a processor, the above-mentioned smart substation multi-bay system-level protection function detection method is implemented.

[0034] The above technical solution of the embodiment of the present invention has the following beneficial technical effects:

[0035] 1. By obtaining and sorting the voltage values ​​of the grid connection points, and combining the network topology structure, the first busbar closest to the fault point can be accurately found, providing key positioning information for subsequent fault isolation, and improving the accuracy and efficiency of fault location. ;

[0036] 2. The second busbar connected to the first busbar is determined based on the change in the voltage value of the grid connection point after the first busbar is locked, which can accurately identify the opposite busbar closely related to the fault, thereby comprehensively determining the part that needs to be isolated, which helps to perform fault isolation operations more accurately;

[0037] 3. From obtaining voltage values ​​to determining the busbar and then to isolation, the fault area in the power network can be quickly and effectively isolated, reducing the impact of the fault on the entire power network and ensuring the stable operation of the power network and power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of a method for rapid fault isolation of a power network powered by a power electronic power supply provided by an embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of power network data interaction provided by an embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of the electrical structure of a power network provided by an embodiment of the present invention;

[0041] Figure 4 It is a schematic diagram of power network fault isolation logic provided by an embodiment of the present invention;

[0042] Figure 5 It is a block diagram of a module of a power network rapid fault isolation device powered by a power electronic power supply provided by an embodiment of the present invention.

[0043] Reference numerals:

[0044] 1. Voltage detection module, 2. First fault detection module, 3. Second fault detection module. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0046] The local power grid of renewable energy or the regional energy autonomous power grid has no connection or weak connection with the large power grid, and the internal power supply of these two power grids is mainly power electronic power supply equipment. Because power electronic power supply equipment has the advantages of easy construction, simple operation and maintenance, low carbon and environmental protection, the local power grid of renewable energy or the regional energy autonomous power grid powered by 100% power electronic power supply equipment has gradually been applied. Both power grids directly serve the power loads of power users, are close to distributed clean power sources and power loads, have a small power supply range, and the power grid adopts an architecture suitable for load and distributed power access. Busbars at all levels are generally connected to loads and distributed power electronic power equipment.

[0047] Please refer to Figure 1 A first aspect of an embodiment of the present invention provides a method for rapid fault isolation of a power network powered by a power electronic power supply, wherein the power network includes a plurality of distributed power electronic power supply devices, and the method includes the following steps:

[0048] Step S200, when the grid connection point voltage is abnormal, respectively obtain the grid connection point voltage values ​​of a plurality of power electronic power supply devices at the same preset time, and sort the plurality of grid connection point voltage values ​​from small to large.

[0049] The grid connection point voltage abnormality means that the grid connection point voltage is lower than a certain limit range of the rated voltage, for example, lower than 80% of the rated voltage, which is only used to illustrate the situation of grid connection point voltage abnormality, and can also be 70%, and the present invention is not limited to this.

[0050] Optionally, the power network includes: a renewable energy local grid or a regional energy autonomous grid.

[0051] Step S300: Based on the topological structure of the power network and in combination with the sorting result, determine that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network.

[0052] Step S400, blocking the trigger pulse of the power electronic power supply device corresponding to the first bus, determining that the opposite bus connected to the first bus is the second bus according to the voltage value change of the grid connection point before and after blocking, and isolating the first bus from the second bus.

[0053] The renewable energy local power grid or regional energy autonomous power grid powered by power electronic power supply equipment includes power electronic power supply equipment with multiple points. The power electronic power supply equipment adopts a grid-building or grid-following control strategy. When the power grid fails, each power electronic power supply equipment with multiple points feels the voltage fluctuation. Each power electronic power supply equipment that adopts grid-following control with added voltage support or direct grid-building control will provide reactive power for voltage support and adjust the active current and reactive current according to the external voltage drop. The converter will continuously sample the grid connection point voltage in real time during operation.

[0054] Through the above-mentioned fault isolation method, the voltage collection of each busbar of the power network generally does not require additional equipment. Under the premise of ensuring that the investment cost is not greatly increased, the fault area can be identified within 100 milliseconds; the multi-point voltage amplitude sorting and comparison criterion is adopted, which has low requirements for data synchronization and data accuracy, and can effectively reduce costs; it realizes the rapid isolation of internal faults of renewable energy local power grids or regional energy autonomous power grids, and provides a guarantee for continued power supply to non-fault areas, thereby effectively reducing power outage time and reducing the workload of operation and maintenance personnel.

[0055] Furthermore, the step S200 of respectively obtaining the grid connection point voltage values ​​of a plurality of power electronic power supply devices at the same time and sorting the plurality of grid connection point voltage values ​​from small to large includes:

[0056] Step S210, obtaining a plurality of grid connection point voltage values ​​of each power electronic power supply device within a preset time period.

[0057] Step S220, calculating the per unit value of the average value of the grid connection point voltage of each power electronic power supply device in a preset time period.

[0058] Step S230: sorting the per unit values ​​of a plurality of power electronic power supply devices from small to large.

[0059] After a fault, the closer the node is to the fault location, the lower the voltage amplitude is. By utilizing the high sampling frequency of power electronic power supply equipment, the voltage changes at the sampling points are tracked, and the nodes are sorted using the average per-unit value of the lowest voltage amplitude within a fixed time window in the same time interval. Based on the preset power grid topology, a comparative analysis is performed to determine the fault scope and isolate the fault.

[0060] The grid connection point voltage value U obtained by the power electronic power supply equipment converter PCC, according to the sampling frequency, a voltage amplitude is calculated approximately every 200 microseconds. Using a fast communication network that supports the GOOSE ring network communication architecture, the power electronic power supply equipment will U PCC Real-time upload: the centralized control system of the power network receives the data uploaded by the power electronic power supply equipment and selects a fixed time window (such as 2ms) at the same time point for U PCC Amplitude average, get U PCCav , multi-point layout of power electronic power supply equipment can obtain multi-point U PCCav , denoted as UP CCav1-1 , U PCCav2-1 , ...U PCCav2-1 , ...U PCCavn-n .

[0061] Get each point U within a fixed time interval (such as 20ms) PCCav The minimum per unit value is calculated according to the U PCCav The busbar with the smallest grid voltage amplitude is sorted by the size of the minimum per-unit value, and the busbar with the smallest grid voltage amplitude is obtained. In combination with the topological architecture and the trend of grid voltage amplitude change between nodes (the closer the node is to the fault location, the lower the voltage amplitude is), the busbar closest to the fault point is confirmed, that is, the busbar with the smallest grid voltage amplitude and the grid voltage amplitude in each direction away from the fault point is increasing in the order of node distance; the trigger pulse of the power electronic power supply equipment connected to the busbar closest to the fault point is blocked, and the opposite end busbar U of each line connected to the busbar closest to the fault point after blocking is compared and analyzed. PCCavn-n The extreme value during the change, according to U PCCavn-n Extreme value and U before locking PCCavn-n The busbar at the other end of the faulty line is judged to be the one with the smallest change, and the fault is isolated.

[0062] Further, after determining in step S300 that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the power network fault point in combination with the sorting result, the following steps are included:

[0063] Step S310, obtaining a plurality of opposite-end busbars connected to the first busbar;

[0064] Step S320, determining whether the average grid connection point voltage of each pair of end busbars and the corresponding busbars connected thereto increases in sequence;

[0065] Step S330: if yes, determine that the first bus is the bus closest to the fault point of the power network;

[0066] Step S340: If no, the step of obtaining the grid-connected point voltage values ​​of a plurality of power electronic power supply devices at the same time is re-executed.

[0067] After determining in step S300 that the bus corresponding to the minimum grid-connected point voltage value is the first bus closest to the power network fault point, the opposite-end bus judgment process is then executed. First, obtain a number of opposite-end buses connected to the first bus, and for each opposite-end bus and its respective connected bus, determine whether their average grid-connected point voltage values ​​show a trend of increasing in sequence. If this condition is met, it is determined that the first bus is indeed the bus closest to the power network fault point; if this condition is not met, then it is necessary to re-execute the initial step of obtaining the grid-connected point voltage values ​​of several power electronic power supply devices at the same time in step S200 after step S340, so as to further accurately determine the situation of the bus closest to the fault point, thereby providing a reliable basis for subsequent accurate fault isolation operations.

[0068] Further, the step S400 of determining the opposite bus connected to the first bus as the second bus according to the change in the voltage value of the grid connection point before and after the blocking includes:

[0069] Step S410, respectively obtaining the average values ​​of the grid connection point voltages of a plurality of opposite-end buses connected to the first bus after blocking in a preset time period.

[0070] After the trigger pulse of the power electronic power supply device corresponding to the first bus is locked, the average value of the grid connection point voltage of several opposite-end buses connected to the first bus within a preset time period is obtained respectively, providing basic data for subsequent calculation and judgment.

[0071] Step S420, calculating the average value change of the grid connection point voltage of each pair of end buses before and after the blocking.

[0072] For each opposite-end bus, the average change in the grid connection point voltage before and after the blocking operation is calculated. Through this calculation, the voltage change of each opposite-end bus caused by the first bus blocking operation can be clearly understood.

[0073] Step S430, selecting the opposite-end bus with the smallest grid-connection point voltage average value change as the second bus.

[0074] The opposite bus with the smallest average voltage change at the grid connection point is selected from all the opposite busbars and determined as the second busbar. In this way, the opposite busbar closely related to the first busbar in the current fault isolation scenario is accurately found, so that the first busbar and the second busbar can be effectively isolated in the future.

[0075] Furthermore, before respectively obtaining the grid connection point voltage values ​​of a plurality of power electronic power supply devices at the same preset time in step S200 and sorting the plurality of grid connection point voltage values ​​from small to large, the method further includes:

[0076] Step S110: if there is no power electronic power supply equipment on a busbar of the power network, a voltage sampling component is set on the busbar.

[0077] When there is no power electronic power supply on a bus in the power network, a voltage sampling component needs to be set on the bus to ensure that relevant voltage information can be obtained for the bus that is not directly connected to the power electronic power supply device.

[0078] Step S120, obtaining the grid connection point voltage value of the voltage sampling component at the same preset time.

[0079] By setting up a voltage sampling component, the grid connection point voltage value at the same preset time is obtained, thereby providing a complete data basis for the subsequent step S200 to comprehensively and accurately obtain and process the grid connection point voltage values ​​of all relevant buses, so as to further carry out related operations on power network fault isolation.

[0080] For further information, please refer to Figure 2 ,Each power electronic power supply device and the centralized control system of the power network transmit data through GOOSE messages.

[0081] There are a large number of power electronic power devices in the power network and they are widely distributed. GOOSE messages can efficiently handle a large amount of data interaction and can transmit data of multiple power electronic power devices simultaneously in a network environment. Each message has a clear identification and priority setting. This enables the centralized control system of the power network to process the received data according to different priorities. For example, fault alarm information may be set to a high priority and processed first, so that the fault can be located quickly, while some parameter update information under normal operating conditions can be processed according to normal priority. This efficient data interaction method helps to optimize the operation and management of the power network.

[0082] In addition, please refer to Figure 2 , before respectively obtaining the grid connection point voltage values ​​of several power electronic power supply devices at the same time, it also includes:

[0083] The centralized control system of the power network and several power electronic power supply devices are synchronized through IEEE 1588 synchronization, B code synchronization, GOOSE message synchronization, second pulse synchronization or network SNTP synchronization.

[0084] Please refer to the following Figure 3 and Figure 4 , regional energy autonomous grid or local grid powered by 100% power electronic power supply equipment Figure 2As shown in the figure, the architecture is suitable for load and distributed power access. In general, each bus is connected to load and distributed power electronic power equipment. It includes 9 bus segments. The switch number is associated with the bus number. For example, switch No. 1 on bus No. 1 is numbered K. 11 .

[0085] Use the following steps:

[0086] Step 1: Preset the overall topology of the power network, number each switch according to the bus, sense the switch status in real time, and determine the operating network topology based on the switch position.

[0087] Step 2: The grid connection point voltage value U obtained in real time by the DG converter on the 8th bus (the DG on the 4# bus is not running) PCC , and determine whether the amplitude exceeds the limit.

[0088] Step 3: According to the U uploaded by the power electronic power supply equipment during the abnormality PCC Amplitude data (200 microseconds per point), select a fixed time window (such as 2ms) at the same time point for U PCC Amplitude average, get 8 bus segments U PCCav .

[0089] Step 4: Get the U of each of the 8 bus segments within a fixed time interval (such as 20ms). PCCav The minimum per unit value is calculated according to the U PCCav The busbars with the smallest grid-connected voltage amplitude are obtained by sorting the busbars according to the minimum per-unit values, such as busbar 6#.

[0090] Step 5: Combine the topology and the voltage amplitude change trend of each busbar (the closer the node is to the fault location, the lower the voltage amplitude is) to confirm the busbar closest to the fault point - the busbar with the smallest grid-connected voltage amplitude and the busbar with an increasing grid-connected voltage amplitude in each direction away from the fault according to the order of node distance. For example, the voltages of 2# and 8# buses are higher than those of 6# bus, and the voltages of 2# and 5# are in ascending order, and the voltages of 2#, 1#, 3#, 7#, and 9# are also in ascending order, then it is confirmed to be 6# bus.

[0091] Step 6: Block the trigger pulse of the power electronic power supply equipment connected to the busbar (6# busbar) closest to the fault point, and compare and analyze the opposite busbars (2# and 8# buses) of each line connected to the busbar closest to the fault point after blocking. PCCavn-n Extreme value, according to U PCCavn-n Extreme value and U before locking PCCavn-n The bus with the smallest change is judged to be the other end of the faulty line (for example, if the voltage change of bus 2# is less than that of bus 8#, it is bus 2#).

[0092] Step 7: Issue a remote switch command to disconnect K 25and K 61 , perform fault isolation.

[0093] Accordingly, please refer to Figure 5 A second aspect of an embodiment of the present invention provides a power network rapid fault isolation device powered by a power electronic power supply, wherein the power network includes a plurality of distributed power electronic power supply devices, and the device includes:

[0094] A voltage detection module 1 is used to obtain the grid connection point voltage values ​​of several power electronic power supply devices at the same preset time when the grid connection point voltage is abnormal, and to sort the several grid connection point voltage values ​​from small to large;

[0095] A first fault detection module 2, which is used to determine, based on the topological structure of the power network and in combination with the sorting result, that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network;

[0096] The second fault detection module 3 is used to lock the trigger pulse of the power electronic power supply device corresponding to the first bus, determine that the opposite bus connected to the first bus is the second bus according to the change in the voltage value of the grid connection point before and after locking, and isolate the fault line between the first bus and the second bus.

[0097] Correspondingly, the third aspect of an embodiment of the present invention also provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the above-mentioned smart substation multi-compartment system-level protection function detection method.

[0098] In addition, the fourth aspect of the embodiment of the present invention further provides a computer-readable storage medium on which computer instructions are stored, and when the instructions are executed by a processor, the above-mentioned smart substation multi-bay system-level protection function detection method is implemented.

[0099] The embodiment of the present invention aims to protect a method for rapid fault isolation of an electric power network powered by a power electronic power supply, wherein the electric power network includes a plurality of distributed power electronic power devices, and the method includes the following steps: when the grid connection point voltage is abnormal, respectively obtain the grid connection point voltage values ​​of the plurality of power electronic power devices at the same preset time, and sort the plurality of grid connection point voltage values ​​from small to large; based on the topological structure of the electric power network, determine the bus corresponding to the minimum grid connection point voltage value as the first bus closest to the fault point of the electric power network in combination with the sorting result; lock the trigger pulse of the power electronic power device corresponding to the first bus, determine the opposite bus connected to the first bus as the second bus according to the change in the grid connection point voltage value before and after locking, and isolate the fault line between the first bus and the second bus. The above technical scheme has the following effects:

[0100] 1. By obtaining and sorting the voltage values ​​of the grid connection points, and combining the network topology structure, the first busbar closest to the fault point can be accurately found, providing key positioning information for subsequent fault isolation, and improving the accuracy and efficiency of fault location. ;

[0101] 2. The second busbar connected to the first busbar is determined based on the change in the voltage value of the grid connection point after the first busbar is locked, which can accurately identify the opposite busbar closely related to the fault, thereby comprehensively determining the part that needs to be isolated, which helps to perform fault isolation operations more accurately;

[0102] 3. From obtaining voltage values ​​to determining the busbar and then to isolation, the fault area in the power network can be quickly and effectively isolated, reducing the impact of the fault on the entire power network and ensuring the stable operation of the power network and power supply reliability.

[0103] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0104] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0105] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for rapid fault isolation of a power network powered by a power electronic power supply, characterized in that: The power network includes a plurality of distributed power electronic power supply devices, and the method includes the following steps: When the grid connection point voltage is abnormal, respectively obtaining grid connection point voltage values ​​of a plurality of the power electronic power supply devices at the same preset time, and sorting the plurality of grid connection point voltage values ​​from small to large; Based on the topological structure of the power network, combined with the sorting result, determine that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network; The trigger pulse of the power electronic power supply device corresponding to the first bus is locked, and the opposite bus connected to the first bus is determined to be the second bus according to the voltage value change of the grid connection point before and after locking, and the fault line between the first bus and the second bus is isolated.

2. The method for rapid fault isolation of a power network powered by a power electronic power supply according to claim 1, characterized in that: The step of respectively obtaining the grid connection point voltage values ​​of a plurality of the power electronic power supply devices at the same time and sorting the plurality of grid connection point voltage values ​​from small to large includes: Acquire a plurality of grid connection point voltage values ​​of each of the power electronic power supply devices within a preset time period; Calculating the per unit value of the average value of the grid connection point voltage of each of the power electronic power supply devices during the preset time period; The per-unit values ​​of the power electronic power supply devices are sorted from small to large.

3. The method for rapid fault isolation of a power network powered by a power electronic power supply according to claim 2, characterized in that: After the bus corresponding to the minimum voltage value of the grid connection point is determined to be the first bus closest to the power network fault point in combination with the sorting result, the method includes: Acquire a plurality of opposite-end busbars connected to the first busbar; Determine whether the average grid connection point voltage of each of the opposite-end busbars and the corresponding busbars connected thereto increases in sequence; If yes, determining that the first bus is the bus closest to the fault point of the power network; If not, the step of obtaining the grid-connected point voltage values ​​of the plurality of power electronic power supply devices at the same time is performed again.

4. The method for rapid fault isolation of a power network powered by a power electronic power supply according to claim 1, characterized in that: The method of determining the opposite busbar connected to the first busbar as the second busbar according to the change in the voltage value of the grid connection point before and after the blocking includes: Respectively obtaining the average voltage of the grid connection point of a plurality of opposite-end buses connected to the first bus after blocking in the preset time period; Calculate the average value change of the grid connection point voltage of each of the opposite-end buses before and after blocking; The opposite bus with the smallest average voltage change at the grid connection point is selected as the second bus.

5. The method for rapid fault isolation of a power network powered by a power electronic power supply according to claim 1, characterized in that: Before respectively obtaining the grid connection point voltage values ​​of the plurality of power electronic power supply devices at the same preset time and sorting the plurality of grid connection point voltage values ​​from small to large, the method further includes: If there is no power electronic power supply equipment on a busbar of the power network, a voltage sampling component is arranged on the busbar; The grid connection point voltage value of the voltage of the voltage sampling component at the same preset time is obtained.

6. The method for rapid fault isolation of a power network powered by a power electronic power supply according to any one of claims 1 to 5, characterized in that: Each of the power electronic power supply devices and the centralized control system of the power network perform data transmission via GOOSE messages.

7. The method for rapid fault isolation of a power network powered by a power electronic power supply according to claim 6, characterized in that: Before respectively obtaining the grid connection point voltage values ​​of the plurality of power electronic power supply devices at the same time, the method further includes: The centralized control system of the power network and the plurality of power electronic power supply devices are synchronized by IEEE 1588 synchronization, B code synchronization, GOOSE message synchronization, pulse-per-second synchronization or network SNTP synchronization.

8. The method for rapid fault isolation of a power network powered by a power electronic power supply according to any one of claims 1 to 5, characterized in that: The power network includes: a renewable energy local power grid or a regional energy autonomous power grid.

9. A power network rapid fault isolation device powered by a power electronic power supply, characterized in that: The power network includes a plurality of distributed power electronic power supply devices, and the device includes: A voltage detection module, which is used to obtain the grid connection point voltage values ​​of several power electronic power supply devices at the same preset time respectively when the grid connection point voltage is abnormal, and sort the several grid connection point voltage values ​​from small to large; A first fault detection module, which is used to determine, based on the topological structure of the power network and in combination with the sorting result, that the bus corresponding to the minimum voltage value of the grid connection point is the first bus closest to the fault point of the power network; The second fault detection module is used to lock the trigger pulse of the power electronic power supply device corresponding to the first bus, determine that the opposite bus connected to the first bus is the second bus according to the change in the voltage value of the grid connection point before and after locking, and isolate the fault line between the first bus and the second bus.

10. An electronic device, characterized in that: include: at least one processor; And a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the method for rapid fault isolation of an electric power network powered by a power electronic power supply as described in any one of claims 1-8.

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