WO2023098681A1 - 基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品 - Google Patents

基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品 Download PDF

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Publication number
WO2023098681A1
WO2023098681A1 PCT/CN2022/135112 CN2022135112W WO2023098681A1 WO 2023098681 A1 WO2023098681 A1 WO 2023098681A1 CN 2022135112 W CN2022135112 W CN 2022135112W WO 2023098681 A1 WO2023098681 A1 WO 2023098681A1
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WIPO (PCT)
Prior art keywords
fault
circuit breaker
branch
line
power electronic
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PCT/CN2022/135112
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English (en)
French (fr)
Inventor
董巍
庞辉
高冲
裴翔羽
袁艺嘉
陈龙龙
孔明
孙泽来
Original Assignee
国网智能电网研究院有限公司
长沙理工大学
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Publication of WO2023098681A1 publication Critical patent/WO2023098681A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]

Definitions

  • the present disclosure relates to but not limited to the fields of power system relay protection and flexible direct current transmission, and in particular relates to a method for isolating a fault line of a flexible direct current grid based on direct current circuit breaker proactive pre-action, a protection device, a system, a computer storage medium and a computer program product .
  • the flexible DC power grid is an effective solution to achieve smooth access, reliable delivery, optimized configuration and flexible consumption of large-scale renewable clean energy.
  • One of the important development directions of the grand strategy of carbon neutrality compared with the AC system, the flexible DC grid is a "low damping" system, the fault current rises rapidly, the fault spreads quickly, and the fault transient current has no natural zero-crossing point, which is prone to "local faults and the entire network outage" Phenomenon.
  • the overall protection operating time of the DC line is the sum of the fault detection time, the transmission time of the protection action command and the switching operation time of the DC circuit breaker.
  • the flexible DC grid with "low damping" characteristics a long overall protection action time of the DC line is very likely to cause the near-end converter valve to be blocked and the power electronic devices of the main equipment to be damaged.
  • the transmission time of the protection action command can be shortened by the principle of local protection, the sum of the relatively long fault detection time and the DC circuit breaker breaking operation time may also cause the near-end converter valve to be blocked, and even the power electronic devices of the main equipment may be blocked. damage.
  • the purpose of the embodiments of the present disclosure is to provide a flexible DC power grid fault line isolation method, protection device, system, computer storage medium and computer program product based on DC circuit breaker proactive pre-action, which can shorten the overall protection action time of DC lines, Realize rapid isolation of faulty lines in the flexible DC power grid.
  • an embodiment of the present disclosure provides a method for isolating a faulty line of a flexible DC grid based on DC circuit breaker proactive pre-action, including:
  • the fault area identification is used to judge whether the fault of the DC line is an internal fault
  • the fault interference identification is used to judge the Whether the fault in the above-mentioned area is a real fault or interference;
  • fault pole selection is performed, and the corresponding DC circuit breaker is controlled to perform the second commutation operation.
  • the fault identification operation and the action sequence of the breaking operation of the DC circuit breaker are processed in parallel to accelerate the coordination and cooperation of the two, and effectively reduce the overall protection action time of the DC line.
  • the first commutation operation includes: turning off the power electronic switch module on the main branch and turning on the power electronic switch module on the transfer branch, so that the fault current flows from the main branch to The transfer branch is transferred;
  • the opening operation of the fast mechanical switch includes: performing the opening operation of the fast mechanical switch when the fault current is completely transferred from the main branch to the transfer branch;
  • the second commutation operation includes: turning off the power electronic module on the transfer branch, so that the fault current flows to the power electronic switch module on the transfer branch through a diode full bridge The capacitor inside is charged;
  • the energy consumption branch of the DC circuit breaker is turned on, and the Fault current is diverted from the transfer branch to the energy-consuming branch.
  • the first commutation reset operation includes: performing a fast mechanical switch closing operation; turning on the power electronic switch module located on the main branch, and turning off all the power electronic modules located on the transfer branch , so that the line current is transferred from the transfer branch to the main branch; wherein, when the line current is all transferred from the transfer branch to the main branch, the DC circuit breaker resumes normal operation.
  • an embodiment of the present disclosure provides a protection device, the protection device is connected with a DC circuit breaker and a measurement device, and the measurement device collects line data before and after the protection start time and transmits it to the protection device in real time.
  • the protection device includes: an acquisition part, a fault identification part and a DC circuit breaker breaking operation control part;
  • the acquisition part is configured to acquire line data before and after the start time of the DC line protection system when the DC line protection system is started;
  • the fault identification part is configured to identify a fault area according to the line data; the fault area identification is used to determine whether an internal fault occurs on the DC line; if an internal fault occurs on the DC line, perform fault Interference identification; the fault interference identification is used to judge whether the fault in the area is a real fault or interference; when the fault in the area is a real fault, perform fault pole selection;
  • the DC circuit breaker breaking operation control part is configured to control the corresponding DC circuit breaker to perform the first commutation operation and the fast mechanical switch opening operation in sequence in the case of an internal fault on the DC line; If the fault in the zone is the interference, control the corresponding DC circuit breaker to perform the first commutation reset operation; if the fault in the zone is a real fault, control the corresponding DC circuit breaker to perform the second commutation reset operation stream operations.
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to turn off the power electronic switch module on the main branch and turn on the power electronic switch module on the transfer branch, so that The fault current is transferred from the main branch to the transfer branch; and the corresponding DC circuit breaker is controlled to perform the opening operation of the fast mechanical switch when the fault current is completely transferred from the main branch to the transfer branch.
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to switch off the power electronic module located on the transfer branch, so that the fault current flows through the diode full bridge to the The capacitor in the power electronic switch module on the transfer branch is charged
  • the energy consumption branch of the DC circuit breaker is turned on, The fault current is diverted from the transfer branch to the energy consumption branch.
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to perform a fast mechanical switch closing operation; control the corresponding DC circuit breaker to turn on the power electronic switch module located on the main branch , and turn off all power electronic modules located on the transfer branch, so that the line current is transferred from the transfer branch to the main branch; wherein, in the case where the line current is all transferred from the transfer branch to the main branch , the DC circuit breaker resumes normal operation.
  • an embodiment of the present disclosure provides a protection device, including a processor and a memory, and the memory stores a computer program that is invoked to implement the above-mentioned flexible DC power grid fault line based on the proactive pre-operation of the DC circuit breaker The operation corresponding to the isolation method.
  • an embodiment of the present disclosure provides a protection system, the protection system includes a measurement device, the above-mentioned protection device and a DC circuit breaker, based on the principle of in-situ protection, the protection device and the measurement device, DC circuit breaker The circuit breaker is directly connected.
  • the number of the protection devices and the DC circuit breakers are equal, and there is a one-to-one correspondence.
  • a DC circuit breaker is equipped on both sides of the DC line, and each DC circuit breaker has a corresponding protection device and measuring device.
  • the protection device corresponds to the DC circuit breaker one by one, and the local protection action command directly acts on the local DC circuit breaker. At the same time, as a backup protection action command, it acts on the DC circuit breaker on the other side of the DC line.
  • the DC circuit breaker is a hybrid DC circuit breaker
  • an embodiment of the present disclosure provides a computer storage medium, the storage medium stores a computer program, and the computer program is invoked by a processor to perform the above-mentioned flexible DC power grid fault line isolation based on the proactive pre-operation of the DC circuit breaker The operation corresponding to the method.
  • an embodiment of the present disclosure provides a computer program product, the computer program product includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes the above-mentioned DC-based Corresponding operation of circuit breaker proactive fault line isolation method for flexible direct current grid.
  • the fault identification operation and the breaking operation of the DC circuit breaker are processed in parallel, specifically: after receiving the fault area identification exit instruction, the corresponding DC circuit breaker Execute break operation.
  • the embodiment of the present disclosure performs parallel accelerated coordination and cooperation between the protection exit and the action of the DC circuit breaker, which practicably reduces the overall protection action time of the DC line .
  • the method proposed in the embodiment of the present disclosure can realize the rapid isolation of the faulty line of the flexible DC grid, reduce the risk of the near-end converter valve blocking and the damage of the power electronic device of the main equipment, and can guarantee the system to the greatest extent. sound and continuous reliable operation. It can be seen from this that the method for fast isolation of faulty lines in flexible DC grids based on the proactive pre-action of DC circuit breakers proposed in the embodiments of the present disclosure meets the requirements for relay protection of flexible DC grid lines and provides a powerful solution to the problem of fast isolation of faulty lines in flexible DC grids. support.
  • Fig. 1 is a configuration diagram of a DC line fast protection device and a DC circuit breaker provided in an embodiment of the present disclosure in a flexible DC grid;
  • FIG. 2 is a topological structure diagram of a hybrid DC circuit breaker provided by an embodiment of the present disclosure
  • Fig. 3 is a sequence diagram of faulty line isolation based on proactive pre-action of a circuit breaker provided by an embodiment of the present disclosure
  • Figure 4 is a sequence diagram of fault line isolation of traditional serial "protection first, then circuit breaker action"
  • Fig. 5 is a schematic diagram of the breaking operation process of the hybrid DC circuit breaker provided by the embodiment of the present disclosure
  • Fig. 6 is a schematic diagram of a ⁇ 500kV flexible direct current grid provided by an embodiment of the present disclosure
  • Fig. 7a is a schematic diagram of the change of the upper bridge arm current of the converter station S 3 A phase in the method proposed in the embodiment of the present disclosure and the traditional serial method;
  • Fig. 7b is a schematic diagram of the change of fault line current between the method proposed in the embodiment of the present disclosure and the traditional serial method;
  • Fig. 7c is a schematic diagram of the variation of the branch current of the DC circuit breaker in the method proposed in the embodiment of the present disclosure and the traditional serial method.
  • a method for isolating a faulty line of a flexible DC power grid based on the proactive pre-action of a DC circuit breaker includes the following steps:
  • Step 1 After the DC line protection system is started, collect the positive and negative voltage and current data before and after the protection start time, and construct a "data window" for faulty line identification.
  • the identification of the fault line is to use the positive and negative pole voltage and current data before and after the protection start time.
  • other situations or types of line data can be selected, and mature technical means can be used to realize the fault Line identification.
  • Step 2 Using the positive and negative pole voltage and current data to perform fault identification operations and parallel processing DC circuit breaker breaking operations;
  • the fault identification operation includes three aspects, namely: fault area identification, fault interference identification and fault pole selection.
  • the fault area identification refers to the determination of whether an internal fault or an external fault occurs on the DC line.
  • the fault area identification exit command is output, and the DC circuit breaker performs the breaking operation after receiving the fault area identification exit command as the boundary point;
  • the fault area identification exit command will be blocked, that is, the DC circuit breaker will not perform breaking operation.
  • Fault interference identification refers to judging whether a real fault or interference occurs on the DC line in the area.
  • Fault pole selection refers to the determination of whether a positive ground fault, a negative ground fault or a double-pole short-circuit fault occurs on the DC line in the area. According to the logic of fault identification, the fault identification in the embodiments of the present disclosure first performs fault area identification, and then performs fault interference identification. If the fault interference identification is determined to be a fault, then perform fault pole selection.
  • the embodiments of the present disclosure perform parallel processing on the breaking operation of the DC circuit breaker while the fault identification operation is being performed. Specifically:
  • the corresponding DC circuit breaker After receiving the fault area identification exit command, the corresponding DC circuit breaker performs the first commutation operation, turns off the power electronic switch module on the main branch and turns on the power electronic switch module on the transfer branch at the same time, The fault current is quickly transferred from the main branch to the transfer branch. After the fault current is completely transferred from the main branch to the transfer branch, the fast mechanical switch performs the opening operation.
  • the fault identification is divided into three time points: the exit time of the start command, the exit time of the fault area identification command, and the exit time of the fault pole selection action command. If the start command is used as the first commutation action command of the DC circuit breaker, the DC circuit breaker Misoperation is prone to occur; in the embodiment of the present disclosure, the fault area identification command with high reliability is used as the first commutation action command of the DC circuit breaker, and the DC circuit breaker performs proactive pre-operation to quickly isolate the faulty line.
  • the fault interference identification is carried out synchronously. If the fault interference is identified as interference, the corresponding DC circuit breaker performs the first commutation and reset operation, that is, the fast mechanical switch closing operation is performed first, and then the switch on the main circuit breaker is turned on.
  • the power electronic switch module on the branch circuit simultaneously turns off the power electronic switch module located on the transfer branch circuit, and quickly transfers the line current from the transfer branch circuit to the main branch circuit until the DC circuit breaker resumes normal operation.
  • the DC line protection system performs fault pole selection; after receiving the protection exit action command (fault pole selection action command), the DC circuit breaker at the fault pole performs the second commutation operation, At the same time, the DC circuit breaker in the non-fault pole performs the first commutation recovery operation.
  • the second commutation operation of the DC circuit breaker at the fault pole is to turn off the power electronic module on the transfer branch, and the fault current charges the capacitance in the multi-stage power electronic switch module on the branch through the diode full bridge.
  • the energy-consuming branch of the DC circuit breaker When the capacitor voltage in the power electronic module of the transfer branch is greater than the start-up threshold voltage of the Metal Oxide Varisters (MOV) in the energy-consuming branch, the energy-consuming branch of the DC circuit breaker is turned on, and the fault current rapidly changes from The transfer branch is transferred to the energy consumption branch, and the DC circuit breaker completes the breaking operation.
  • MOV Metal Oxide Varisters
  • the preferred DC circuit breaker is a hybrid DC circuit breaker, which consists of three parts: a main branch, a transfer branch and an energy consumption branch. Among them, the period from when the DC circuit breaker receives the action command to when the DC line current begins to drop is the breaking operation time of the DC circuit breaker. As shown in Figure 4, during the breaking operation time, the DC circuit breaker mainly completes the following three processes:
  • the hybrid DC circuit breaker quickly turns off the power electronic switch module on the main branch and simultaneously turns on the power electronic switch module on the transfer branch.
  • the DC line current is quickly transferred from the main branch to the transfer branch, and the commutation process takes about 0.6ms;
  • the DC line current flowing through the main branch drops to zero, that is, after the DC line current is completely transferred from the main branch to the transfer branch, the fast mechanical switch performs an arc-free opening operation, and the opening process takes about 2ms;
  • the power electronic switch module located on the transfer branch is turned off, and the DC line current charges the capacitance in the multi-level power electronic switch module on the branch through the diode full bridge.
  • the capacitor voltage in the power electronic module of the transfer branch is greater than the start-up threshold voltage of the MOV protection of the energy consumption branch, the energy consumption branch is turned on, and the DC line current is quickly transferred from the transfer branch to the energy consumption branch.
  • the process takes about 0.1ms;
  • the breaking operation time of the hybrid DC circuit breaker is about 2.7ms.
  • the breaking operation process of the DC circuit breaker is shown in the figure.
  • t 0 The DC line is faulty, and the fault current begins to increase;
  • t 1 The DC circuit breaker receives the protection action command;
  • t 1 -t 2 The control system delays, about 0.3ms;
  • t 2 The DC circuit breaker executes the first Secondary commutation, the fault current is transferred from the main branch to the transfer branch, about 0.6ms;
  • t 2 -t 3 After the first commutation, the DC circuit breaker performs fast mechanical switch opening, which takes about 2ms;
  • t 3 The DC circuit breaker performs the second commutation to transfer the fault current from the transfer branch to the energy consumption branch, about 0.1ms.
  • t 4 The DC circuit breaker completes the breaking operation, and the terminal voltage of the DC circuit breaker is equal to the rated voltage
  • Figure 4 is a timing diagram based on the traditional serial fault line isolation method of "protecting the outlet first, then operating the circuit breaker".
  • the fast and reliable identification of the fault line and the action of the circuit breaker are in the serial working mode, that is, after the fast and reliable identification device of the fault line completes the protection startup and fault identification within 3ms, the DC circuit breaker performs corresponding operations according to the protection action instruction.
  • the fault identification in Fig. 4 includes fault distinction recognition, fault interference recognition and fault pole selection.
  • the overall protection action time of the DC line is the sum of the fast and reliable identification time of the faulty line and the breaking operation time of the DC circuit breaker, that is, 6ms.
  • the hybrid direct current circuit breaker after receiving the fault area identification exit command, performs the first commutation and fast mechanical switch opening operation.
  • the DC circuit breaker located on the faulty line After receiving the protection exit action instruction (fault pole selection), the DC circuit breaker located on the faulty line performs the second commutation operation, which is compared with the traditional serial fault line isolation method of "protecting the exit first, and then operating the circuit breaker". Compared, the overall protection action time of the DC line can be reduced to (3+ ⁇ t 1 + ⁇ 1 )ms.
  • this embodiment provides a protection device that is connected to a high-speed measurement device and a DC circuit breaker.
  • the high-speed measurement device collects the positive and negative DC line voltage and current data before and after the protection start time and transmits them to the protection device in real time.
  • the protection device uses the positive and negative DC line voltage and current data to carry out fault identification operation and parallel processing control of DC circuit breaker breaking operation.
  • the protection device includes: an acquisition part, a fault identification part and a DC circuit breaker breaking operation control part. in:
  • the acquisition part is configured to acquire line data before and after the start time of the DC line protection system when the DC line protection system is started;
  • the fault identification part is configured to identify a fault area according to the line data; the fault area identification is used to determine whether an internal fault occurs on the DC line; if an internal fault occurs on the DC line, perform fault Interference identification; the fault interference identification is used to judge whether the fault in the area is a real fault or interference; when the fault in the area is a real fault, perform fault pole selection;
  • the DC circuit breaker breaking operation control part is configured to control the corresponding DC circuit breaker to perform the first commutation operation and the fast mechanical switch opening operation in sequence in the case of an internal fault on the DC line; If the fault in the zone is the interference, control the corresponding DC circuit breaker to perform the first commutation reset operation; if the fault in the zone is a real fault, control the corresponding DC circuit breaker to perform the second commutation reset operation stream operations.
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to turn off the power electronic switch module on the main branch and turn on the power electronic switch module on the transfer branch, so that The fault current is transferred from the main branch to the transfer branch; and the corresponding DC circuit breaker is controlled to perform the opening operation of the fast mechanical switch when the fault current is completely transferred from the main branch to the transfer branch.
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to switch off the power electronic module located on the transfer branch, so that the fault current flows through the diode full bridge to the The capacitor in the power electronic switch module on the transfer branch is charged;
  • the capacitor voltage in the power electronic module on the transfer branch is greater than the starting threshold voltage of the metal oxide variable resistor MOV of the energy consumption branch, the energy consumption branch of the DC circuit breaker is turned on, The fault current is diverted from the transfer branch to the energy consumption branch. .
  • the DC circuit breaker breaking operation control part is further configured to control the corresponding DC circuit breaker to perform a fast mechanical switch closing operation; control the corresponding DC circuit breaker to turn on the power electronic switch module located on the main branch , and turn off all power electronic modules located on the transfer branch, so that the line current is transferred from the transfer branch to the main branch; wherein, in the case where the line current is all transferred from the transfer branch to the main branch , the DC circuit breaker resumes normal operation.
  • a DC circuit breaker is equipped on both sides of the DC line, and each DC circuit breaker has a corresponding protection device and measurement device.
  • the number of protection devices and DC circuit breakers are equal and corresponding to each other. That is, the exit command of the local protection device acts directly on the local DC circuit breaker as the main protection, and at the same time acts on the DC circuit breaker on the other side of the DC line as a backup protection action command.
  • fault identification module and the DC circuit breaker breaking operation control module in the protection device may be integrated in one processing unit, or physically exist separately, which is not specifically limited in the embodiments of the present disclosure.
  • An embodiment of the present disclosure provides a protection device, which includes a processor and a memory, the memory stores a computer program, and the processor invokes the computer program to execute the method corresponding to the fault line isolation method of the flexible DC power grid based on the proactive pre-action of the DC circuit breaker. operate.
  • the so-called processor may be a central processing unit (Central Processing Unit, CPU), and the processor may also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), Application Specific Integrated Circuit (ASIC), off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
  • a general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.
  • the memory which can include read only memory and random access memory, provides instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information.
  • the processor and the memory may be packaged together or disposed in the processor.
  • This embodiment provides a protection system, which is applied to a flexible DC grid, and specifically includes a measurement device, a protection device, and a DC circuit breaker. Based on the principle of in-situ protection, the protection device and the measurement device, DC circuit breaker direct connection.
  • This embodiment provides a computer storage medium, which stores a computer program, and the computer program is invoked by a processor to perform operations corresponding to the above method for isolating a fault line of a flexible DC power grid based on proactive action of a DC circuit breaker. .
  • the storage medium is a computer-readable storage medium, which may be an internal storage unit of the controller described in any of the foregoing embodiments, such as a hard disk or memory of the controller.
  • the readable storage medium can also be an external storage device of the controller, such as a plug-in hard disk equipped on the controller, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, flash card (Flash Card), etc.
  • the readable storage medium may also include both an internal storage unit of the controller and an external storage device.
  • the readable storage medium is used to store the computer program and other programs and data required by the controller.
  • the readable storage medium can also be used to temporarily store data that has been output or will be output.
  • the storage medium includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present disclosure.
  • the aforementioned readable storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disc, etc., which can store program codes. medium.
  • the electromagnetic transient simulation model of the ⁇ 500kV flexible DC power grid is built as shown in the figure.
  • the DC circuit breaker adopts the hybrid DC circuit breaker shown in Figure 2, and the DC line adopts the frequency response model;
  • the converter station S2 is the DC voltage control station, and the converter station S1 , the converter station S3 and the converter station
  • the stable operating power of station S 4 is 1250MW, 2500MW and -3000MW respectively.
  • a bipolar short-circuit fault is set at a distance of 0.5 km from the DC line DL 34 to the converter station S 3 , as shown in the simulation result.
  • Fig. 7a shows the current of the upper bridge arm of the A phase S 3 of the converter station.
  • the current of the upper bridge arm of the S 3 A phase of the converter station is significantly reduced.
  • Fig. 7b shows the fault line current, wherein, compared with the traditional serial fault line isolation method of "protecting the outlet first, then operating the circuit breaker", the fault current is significantly reduced based on the method proposed in the embodiment of the present disclosure.
  • Figure 7c shows the current of each branch of the DC circuit breaker.
  • the DC circuit breaker DB 34 diverts the branch current Significantly reduced.
  • the fault line isolation method of the flexible DC power grid provided by the embodiment of the present disclosure accelerates and coordinates the rapid and reliable identification of the fault line with the action sequence of the DC circuit breaker in parallel, and effectively reduces the overall protection action time of the DC line.
  • An embodiment of the present disclosure provides a method for isolating a faulty line of a flexible DC power grid based on proactive pre-action of a DC circuit breaker, a protection device, a system, a computer storage medium, and a computer program product.
  • the method includes: performing fault detection according to the line data Area identification; the fault area identification is used to judge whether the fault in the DC line is an internal fault; in the case of an internal fault in the DC line, carry out fault interference identification, and control the corresponding DC circuit breaker to execute the first step in sequence.
  • the fault interference identification is used to judge whether the fault in the area is a real fault or interference; when the fault in the area is the interference, control the corresponding DC
  • the circuit breaker performs the first commutation reset operation; in the case that the fault in the zone is a real fault, performs fault pole selection, and controls the corresponding DC circuit breaker to perform the second commutation operation.
  • the embodiments of the present disclosure can shorten the overall protection action time of the DC line, and realize fast isolation of the faulty line of the flexible DC power grid.

Abstract

本公开实施例公开了一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品，本公开实施例将故障识别操作和直流断路器分断操作做并行处理；故障识别操作为：先执行故障区域识别，再进行故障干扰识别，若判定为故障，则执行故障选极；直流断路器的分断操作为：在所述直流线路发生区内故障的情况下，控制相对应的直流断路器依次执行分断操作中的第一次换流操作和快速机械开关分闸操作；在故障干扰识别后判定为干扰的情况下，控制直流断路器执行第一次换流复归操作；在故障干扰识别后判定为故障的情况下，控制直流断路器执行第二次换流操作。

Description

基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品
相关申请的交叉引用
本公开基于申请号为202111441496.2、申请日为2021年11月30日、申请名称为“一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置及其系统”的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此引入本公开作为参考。
技术领域
本公开涉及但不限于电力系统继电保护和柔性直流输电领域，尤其涉及一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品。
背景技术
柔性直流电网是实现大规模可再生清洁能源平滑接入、可靠送出、优化配置和灵活消纳的有效解决方案，是支撑我国构建清洁低碳、安全高效现代能源体系，践行“碳达峰、碳中和”宏伟战略的重要发展方向之一。然而，与交流系统相比，柔性直流电网是一个“低阻尼”系统，故障电流上升迅速，故障蔓延速度快，故障暂态电流无自然过零点，极易发生“局部故障，全网停运”现象。
基于传统串行“先保护出口，后断路器动作”故障隔离思路，直流线路的整体保护动作时间为故障检测时间、保护动作指令传输时间和直流断路器分断操作时间之和。对于具有“低阻尼”特性的柔性直流电网而言，较长的直流线路整体保护动作时间极有可能导致近端换流阀闭锁和主设备电力电子器件损坏。若最大程度地保障柔性直流电网的健全和持续可靠运行，必须切实地减小直流线路整体保护动作时间，在故障暂态电流超过系统主设备电力电子器件的故障耐受能力之前，实现故障线路的快速隔离。目前，虽然可通过就地保护原则缩短保护动作指令传输时间，但是相对较长的故障检测时间和直流断路器分断操作时间之和亦有可能导致近端换流阀闭锁，甚至主设备电力电子器件损坏。
因此，为最大程度地保障柔性直流电网健全和持续可靠运行，基于就地保护原则，在故障线路快速可靠识别和直流断路器分断操作时间均已定的情况下，如何进一步缩短直流线路整体保护动作时间，实现柔性直流电网故障线路快速隔离是亟待解决的关键性 技术问题。
发明内容
本公开实施例的目的是提供一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品，其可缩短直流线路整体保护动作时间，实现柔性直流电网故障线路快速隔离。
一方面，本公开实施例提供的一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法，包括：
在直流线路保护系统启动的情况下，获取所述直流线路保护系统启动时刻前后的线路数据；
根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生的故障是否为区内故障；
在所述直流线路发生区内故障的情况下，进行故障干扰识别，并控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；
在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；
在所述区内故障为真实故障的情况下，进行故障选极，以及控制相应的直流断路器执行第二次换流操作。
本公开实施例将故障识别操作和直流断路器分断操作的动作时序做并行处理，加速两者的协调配合，有效减小直流线路整体保护动作时间。
在一些实施例中，所述第一次换流操作，包括：关断位于主支路上的电力电子开关模块并导通位于转移支路上的电力电子开关模块，使得故障电流从所述主支路向所述转移支路转移；
对应地，所述快速机械开关分闸操作，包括：在所述故障电流从主支路全部转移到转移支路的情况下，执行所述快速机械开关分闸操作；
在一些实施例中，所述第二次换流操作，包括：关断位于所述转移支路上的电力电子模块，使得所述故障电流经二极管全桥对所述转移支路上的电力电子开关模块内的电容进行充电；
其中，在所述转移支路电力上的电子模块内的电容电压大于耗能支路金属氧化物可 变电阻MOV启动阈值电压的情况下，所述直流断路器耗能支路导通，所述故障电流从所述转移支路向所述耗能支路转移。
在一些实施例中，所述第一次换流复归操作，包括：执行快速机械开关合闸操作；导通位于主支路上的电力电子开关模块，并关断位于转移支路上的所有电力电子模块，使得线路电流从转移支路向主支路转移；其中，在所述线路电流全部从转移支路转移到所述主支路的情况下，所述直流断路器恢复正常运行。
第二方面，本公开实施例提供一种保护装置，所述保护装置与直流断路器、测量装置连接，所述测量装置采集保护启动时刻前后的线路数据并实时传输给所述保护装置，所述保护装置包括：获取部分、故障识别部分以及直流断路器分断操作控制部分；
所述获取部分，配置为在直流线路保护系统启动的情况下，获取所述直流线路保护系统启动时刻前后的线路数据；
所述故障识别部分，配置为根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生是否发生区内故障；在所述直流线路发生区内故障的情况下，进行故障干扰识别；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；在所述区内故障为真实故障的情况下，进行故障选极；
所述直流断路器分断操作控制部分，配置为在所述直流线路发生区内故障的情况下，控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；在所述区内故障为真实故障的情况下，控制相应的直流断路器执行第二次换流操作。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于主支路上的电力电子开关模块并导通位于转移支路上的电力电子开关模块，使得故障电流从所述主支路向所述转移支路转移；控制相应的直流断路器在所述故障电流从主支路全部转移到转移支路的情况下，执行所述快速机械开关分闸操作。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于所述转移支路上的电力电子模块，使得所述故障电流经二极管全桥对所述转移支路上的电力电子开关模块内的电容进行充电
其中，在所述转移支路上的电力电子模块内的电容电压大于耗能支路金属氧化物可变电阻MOV启动阈值电压的情况下，所述直流断路器的所述耗能支路导通，所述故障电流从所述转移支路向所述耗能支路转移。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断 路器执行快速机械开关合闸操作；控制相应的直流断路器导通位于主支路上的电力电子开关模块，并关断位于转移支路上的所有电力电子模块，使得线路电流从转移支路向主支路转移；其中，在所述线路电流全部从所述转移支路转移到所述主支路的情况下，所述直流断路器恢复正常运行。
第三方面，本公开实施例提供一种保护装置，包括处理器和存储器，存储器存储了计算机程序，所述计算机程序被调用以实现如上述基于直流断路器前摄预动的柔性直流电网故障线路隔离方法对应的操作。
第四方面，本公开实施例提供一种保护系统，所述保护系统包括测量装置、如上述的保护装置和直流断路器，基于就地化保护原则，所述保护装置与所述测量装置、直流断路器直接连接。
在一些实施例中，所述保护装置与所述直流断路器的数量相等，且一一对应。
其中，直流线路两侧各配备一台直流断路器，每台直流断路器均有相对应的保护装置、测量装置，保护装置与直流断路器一一对应，本地保护动作指令直接作用于本地直流断路器，同时作为后备保护动作指令作用于直流线路另一侧的直流断路器。
在一些实施例中，所述直流断路器为混合式直流断路器，
第五方面，本公开实施例提供一种计算机存储介质，所述存储介质存储计算机程序，所述计算机程序被处理器调用以执行如上述基于直流断路器前摄预动的柔性直流电网故障线路隔离方法对应的操作。
第六方面，本公开实施例提供一种计算机程序产品，所述计算机程序产品包括计算机程序或指令，在所述计算机程序或指令在计算机上运行的情况下，使得所述计算机执行如上述基于直流断路器前摄预动的柔性直流电网故障线路隔离方法对应的操作。
本公开实施例提供的一种柔性直流电网故障线路隔离方法，其故障识别操作和直流断路器的分断操作是并行处理的，具体为：接收到故障区域识别出口指令后，相对应的直流断路器执行分断操作。不同于以往串行“先保护出口，后断路器动作”故障线路隔离方法，本公开实施例将保护出口和直流断路器动作做并行加速协调配合，切实可行地减小了直流线路整体保护动作时间。针对直流线路发生局部故障时，本公开实施例所提方法可实现柔性直流电网故障线路快速隔离，能减小近端换流阀闭锁和主设备电力电子器件损坏的风险，可最大程度地保障系统的健全和持续可靠运行。由此可知，本公开实施例所提基于直流断路器前摄预动的柔性直流电网故障线路快速隔离方法满足柔性直流电网线路继电保护需求，为解决柔性直流电网故障线路快速隔离难题提供了有力支撑。
附图说明
图1是本公开实施例提供的直流线路快速保护装置和直流断路器在柔性直流电网中的配置图；
图2是本公开实施例提供的混合式直流断路器拓扑结构图；
图3是本公开实施例提供的基于断路器前摄预动的故障线路隔离时序图；
图4是传统串行“先保护出后，后断路器动作”故障线路隔离时序图；
图5是本公开实施例提供的混合式直流断路器分断操作过程示意图；
图6是本公开实施例提供的±500kV柔性直流电网示意图；
图7a是本公开实施例所提方法与传统串行方法的换流站S 3A相上桥臂电流的变化示意图；
图7b是本公开实施例所提方法与传统串行方法的故障线路电流的变化示意图；
图7c是本公开实施例所提方法与传统串行方法的直流断路器各支路电流的变化示意图。
具体实施方式
下面将结合附图对本发明的技术方案进行清楚、完整地描述，显然，所描述的实施例是本公开一部分实施例，而不是全部的实施例。基于本公开中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本公开保护的范围。
如图1以及图3所示，本公开实施例提供的一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法，包括如下步骤：
步骤1：直流线路保护系统启动后，采集保护启动时刻前后的正负极电压、电流数据，并构造用于故障线路识别的“数据窗”。本实施例中，进行故障线路的识别是利用保护启动时刻前后的正负极电压、电流数据，其它可行的实施例中可以选择其他情况或类型的线路数据，并利用成熟的技术手段来实现故障线路的识别。
步骤2：利用所述正负极电压、电流数据执行故障识别操作以及并行处理的直流断路器分断操作；
其中，故障识别操作包括三个方面，分别为：故障区域识别、故障干扰识别以及故障选极。其中，故障区域识别指代判定直流线路发生区内故障还是区外故障，区内故障 时，输出故障区域识别出口指令，后续以接收到故障区域识别出口指令为界点直流断路器执行分断操作；区外故障时，闭锁故障区域识别出口指令，即直流断路器不进行分断操作。故障干扰识别指代判定区内直流线路发生真实故障还是干扰。故障选极指代判定区内直流线路发生正极接地故障、负极接地故障还是双极短路故障。根据故障识别的逻辑，本公开实施例中的所述故障识别先执行故障区域识别，再进行故障干扰识别，若故障干扰识别判定为故障，则再执行故障选极。
本公开实施例为减小直流线路整体保护动作时间，在故障识别操作进行的同时，对直流断路器的分断操作做并行处理。具体为：
1.1：待接收到故障区域识别出口指令后，相应的直流断路器进行第一次换流操作，关断位于主支路上的电力电子开关模块并同时导通位于转移支路上的电力电子开关模块，故障电流迅速从主支路向转移支路转移，待故障电流从主支路全部转移到转移支路后，快速机械开关执行分闸操作。
其中，故障识别分三个时间点：启动指令出口时刻、故障区域识别指令出口时刻和故障选极动作指令出口时刻，若以启动指令作为直流断路器第一次换流动作指令，则直流断路器容易出现误动；本公开实施例以可靠性较高的故障区域识别指令作为直流断路器第一次换流动作指令，直流断路器进行前摄预动对故障线路进行快速隔离。
1.2：此时，故障干扰识别同步进行，若故障干扰识别后判定为干扰，相对应的直流断路器执行第一次换流复归操作，即先执行快速机械开关合闸操作，再导通位于主支路上的电力电子开关模块并同时关断位于转移支路上的电力电子开关模块，将线路电流迅速从转移支路向主支路转移，直至直流断路器恢复正常运行。
1.3：若故障干扰识别后判定为故障，直流线路保护系统进行故障选极；接收到保护出口动作指令(故障选极动作指令)后，位于故障极的直流断路器执行第二次换流操作，同时位于非故障极的直流断路器执行第一次换流复归操作。其中，位于故障极的直流断路器第二次换流操作为：关断位于转移支路上的电力电子模块，故障电流经二极管全桥对该支路上的多级电力电子开关模块内的电容充电。在转移支路电力电子模块内的电容电压大于耗能支路金属氧化物可变电阻(Metal Oxide Varisters，MOV)启动阈值电压的情况下，直流断路器耗能支路导通，故障电流迅速从转移支路向耗能支路转移，直流断路器完成分断操作。
如图2所示，本实施例优选直流断路器为混合式直流断路器，其由主支路、转移支路和耗能支路等三部分组成。其中，直流断路器接收到动作指令到直流线路电流开始下 降这段时间为直流断路器分断操作时间。如图4所示，在分断操作时间内，直流断路器主要完成以下3个过程：
(1)第一次换流
混合式直流断路器迅速关断位于主支路上的电力电子开关模块并同时导通位于转移支路上的电力电子开关模块。直流线路电流迅速从主支路向转移支路转移，该换流过程耗时约为0.6ms；
(2)快速机械开关分闸
流经主支路的直流线路电流降为零，即直流线路电流从主支路全部转移到转移支路后，快速机械开关进行无弧分闸操作，该分闸过程耗时约为2ms；
(3)第二次换流
快速机械开关完成分闸后，关断位于转移支路上的电力电子开关模块，直流线路电流经二极管全桥对该支路上的多级电力电子开关模块内的电容进行充电。在转移支路电力电子模块内的电容电压大于耗能支路MOV保护启动阈值电压的情况下，耗能支路导通，直流线路电流迅速从转移支路转移到耗能支路，该换流过程耗时约为0.1ms；
因此，混合式直流断路器分断操作过程，混合式直流断路器的分断操作时间约为2.7ms。直流断路器分断操作过程如图所示。t 0：直流线路发生故障，故障电流开始增大；t 1：直流断路器接收到保护动作指令；t 1-t 2:控制系统延时，约0.3ms；t 2：直流断路器执行第一次换流，将故障电流从主支路转移到转移支路，约0.6ms；t 2-t 3：完成第一次换流后，直流断路器进行快速机械开关分闸，耗时约2ms；t 3：直流断路器执行第二次换流，将故障电流从转移支路转移到耗能支路，约0.1ms。t 4：直流断路器完成分断操作，直流断路器端口电压等于系统额定电压。
如图4所示为基于传统串行“先保护出口，后断路器动作”故障线路隔离方法的时序图。其中，故障线路快速可靠识别与断路器动作处于串行工作模式，即故障线路快速可靠识别装置在3ms内完成保护启动和故障识别后，直流断路器根据保护动作指令进行相应操作。其中，图4中故障识别包含了故障区别识别、故障干扰识别以及故障选极。直流线路整体保护动作时间为故障线路快速可靠识别时间与直流断路器分断操作时间之和，即6ms。
因此，本公开实施例接收到故障区域识别出口指令后，混合式直流断路器进行第一次换流和快速机械开关分闸操作。接收到保护出口动作指令(故障选极)后，位于故障线路的直流断路器进行第二次换流操作，其相较于传统串行“先保护出口，后断路器动 作”故障线路隔离方法相比，直流线路整体保护动作时间可降至(3+Δt 1+τ 1)ms。
基于上述理论性陈述，本实施例提供一种保护装置，该保护装置与高速测量装置和直流断路器连接。其中，高速测量装置采集保护启动时刻前后的正负极直流线路电压、电流数据并实时传输给保护装置。保护装置利用正负极直流线路电压、电流数据进行故障识别操作以及直流断路器分断操作并行处理控制。
保护装置包括：获取部分、故障识别部分以及直流断路器分断操作控制部分。其中：
所述获取部分，配置为在直流线路保护系统启动的情况下，获取所述直流线路保护系统启动时刻前后的线路数据；
所述故障识别部分，配置为根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生是否发生区内故障；在所述直流线路发生区内故障的情况下，进行故障干扰识别；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；在所述区内故障为真实故障的情况下，进行故障选极；
所述直流断路器分断操作控制部分，配置为在所述直流线路发生区内故障的情况下，控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；在所述区内故障为真实故障的情况下，控制相应的直流断路器执行第二次换流操作。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于主支路上的电力电子开关模块并导通位于转移支路上的电力电子开关模块，使得故障电流从所述主支路向所述转移支路转移；控制相应的直流断路器在所述故障电流从主支路全部转移到转移支路的情况下，执行所述快速机械开关分闸操作。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于所述转移支路上的电力电子模块，使得所述故障电流经二极管全桥对所述转移支路上的电力电子开关模块内的电容进行充电；
其中，在所述转移支路上的电力电子模块内的电容电压大于耗能支路金属氧化物可变电阻MOV启动阈值电压的情况下，所述直流断路器的所述耗能支路导通，所述故障电流从所述转移支路向所述耗能支路转移。。
在一些实施例中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器执行快速机械开关合闸操作；控制相应的直流断路器导通位于主支路上的电力电子开关模块，并关断位于转移支路上的所有电力电子模块，使得线路电流从转移支路向主支路转移；其中，在所述线路电流全部从所述转移支路转移到所述主支路的情况下，所 述直流断路器恢复正常运行。
如图1所示，直流线路两侧各配备一台直流断路器，每台直流断路器均有相对应的保护装置、测量装置。保护装置与直流断路器的数量相等且一一对应。即本地保护装置出口指令作为主保护直接作用于本地直流断路器，同时作为后备保护动作指令作用于直流线路另一侧的直流断路器。
需要说明的是，保护装置中的故障识别模块和直流断路器分断操作控制模块，二者可以集中在一个处理单元，也可以是单独物理存在，本公开实施例对此不进行具体的限定。
本公开实施例提供一种保护装置，其包括处理器和存储器，存储器存储了计算机程序，处理器调用计算机程序以执行如上述基于直流断路器前摄预动的柔性直流电网故障线路隔离方法对应的操作。
应当理解，在本公开实施例中，所称处理器可以是中央处理单元(Central Processing Unit，CPU)，该处理器还可以是其他通用处理器、数字信号处理器(Digital Signal Processor，DSP)、专用集成电路(Application Specific Integrated Circuit，ASIC)、现成可编程门阵列(Field-Programmable Gate Array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。存储器可以包括只读存储器和随机存取存储器，并向处理器提供指令和数据。存储器的一部分还可以包括非易失性随机存取存储器。例如，存储器还可以存储设备类型的信息。此外，处理器和存储器可以封装于一体或者设置于处理器内。
本实施例提供一种保护系统，该保护系统应用于柔性直流电网，具体包括测量装置、保护装置和直流断路器，基于就地化保护原则，所述保护装置与所述测量装置、直流断路器直接连接。
其中，保护装置和直流断路器的具体内容可以按照前述实施例的阐述。
本实施例提供了一种计算机存储介质，其存储了计算机程序，计算机程序被处理器调用以执行如上述基于直流断路器前摄预动的柔性直流电网故障线路隔离方法对应的操作。。
所述存储介质为计算机可读存储介质，其可以是前述任一实施例所述的控制器的内部存储单元，例如控制器的硬盘或内存。所述可读存储介质也可以是所述控制器的外部存储设备，例如所述控制器上配备的插接式硬盘，智能存储卡(Smart Media Card，SMC)， 安全数字(Secure Digital，SD)卡，闪存卡(Flash Card)等。在一些实施例中，所述可读存储介质还可以既包括所述控制器的内部存储单元也包括外部存储设备。所述可读存储介质用于存储所述计算机程序以及所述控制器所需的其他程序和数据。所述可读存储介质还可以用于暂时地存储已经输出或者将要输出的数据。基于这样的理解，本公开实施例的技术方案本质上或者说对现有技术做出贡献的部分，或者该技术方案的全部或部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本公开各个实施例所述方法的全部或部分步骤。而前述的可读存储介质包括：U盘、移动硬盘、只读存储器(Read-Only Memory，ROM)、随机存取存储器(Random Access Memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
仿真实例：
基于PSCAD/EMTDC仿真平台，搭建了如图所示的±500kV柔性直流电网电磁暂态仿真模型。其中，直流断路器采用如图2所示的混合式直流断路器，直流线路采用频率响应模型；换流站S 2为直流电压控制站，换流站S 1、换流站S 3和换流站S 4的稳定运行功率分别为1250MW、2500MW和-3000MW。假设故障线路快速可靠识别算法的启动时间和故障区域识别时间分别为Δt 1＝0.1ms和τ 1＝0.8ms，则基于本公开实施例所提柔性直流电网故障线路快速隔离方法，直流线路整体保护动作时间为3.9ms。
2s时刻，在直流线路DL 34距离换流站S 3为0.5km处设置双极短路故障，仿真结果图所示。
对本公开实施例所提基于直流断路器前摄预动的柔性直流电网故障线路快速隔离方法进行性能分析。仿真结果如图7a-图7c所示。
图7a表示换流站S 3A相上桥臂电流。其中，与传统串行“先保护出口，后断路器动作”故障线路隔离方法相比，基于本公开实施例所提方法，换流站S 3A相上桥臂电流明显减小。
图7b表示故障线路电流，其中，与传统串行“先保护出口，后断路器动作”故障线路隔离方法相比，基于本公开实施例所提方法，故障电流显著减小。
图7c表示直流断路器各支路电流，与传统串行“先保护出口，后断路器动作”故障线路隔离方法相比，基于本公开实施例所提方法，直流断路器DB 34转移支路电流显著减小。
综上所述，本公开实施例提供的柔性直流电网故障线路隔离方法将故障线路快速可 靠识别与直流断路器的动作时序进行并行加速协调配合，切实可行地减小了直流线路整体保护动作时间。
需要强调的是，本公开实施例所述的实例是说明性的，而不是限定性的，因此本公开实施例不限于具体实施方式中所述的实例，凡是由本领域技术人员根据本公开实施例的技术方案得出的其他实施方式，不脱离本公开实施例宗旨和范围的，不论是修改还是替换，同样属于本公开实施例的保护范围。
工业实用性
本公开实施例提供了一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品，所述方法包括：根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生的故障是否为区内故障；在所述直流线路发生区内故障的情况下，进行故障干扰识别，并控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；在所述区内故障为真实故障的情况下，进行故障选极，以及控制相应的直流断路器执行第二次换流操作。本公开实施例可缩短直流线路整体保护动作时间，实现柔性直流电网故障线路快速隔离。

Claims (14)

  1. 一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法，包括：
    在直流线路保护系统启动的情况下，获取所述直流线路保护系统启动时刻前后的线路数据；
    根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生的故障是否为区内故障；
    在所述直流线路发生区内故障的情况下，进行故障干扰识别，并控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；
    在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；
    在所述区内故障为真实故障的情况下，进行故障选极，以及控制相应的直流断路器执行第二次换流操作。
  2. 根据权利要求1所述的方法，其中，所述第一次换流操作，包括：
    关断位于主支路上的电力电子开关模块并导通位于转移支路上的电力电子开关模块，使得故障电流从所述主支路向所述转移支路转移；
    对应地，所述快速机械开关分闸操作，包括：
    在所述故障电流从主支路全部转移到转移支路的情况下，执行所述快速机械开关分闸操作。
  3. 根据权利要求2所述的方法，其中，所述第二次换流操作，包括：
    关断位于所述转移支路上的电力电子模块，使得所述故障电流经二极管全桥对所述转移支路上的电力电子开关模块内的电容进行充电；
    其中，在所述转移支路上的电力电子模块内的电容电压大于耗能支路金属氧化物可变电阻MOV启动阈值电压的情况下，所述直流断路器的所述耗能支路导通，所述故障电流从所述转移支路向所述耗能支路转移。
  4. 根据权利要求2所述的方法，其中，所述第一次换流复归操作，包括：
    执行快速机械开关合闸操作；
    导通位于主支路上的电力电子开关模块，并关断位于转移支路上的所有电力电子模块，使得线路电流从转移支路向主支路转移；其中，在所述线路电流全部从所述转移支路转移到所述主支路的情况下，所述直流断路器恢复正常运行。
  5. 一种保护装置，所述保护装置与直流断路器、测量装置连接，所述测量装置配置为采集保护启动时刻前后的线路数据并实时传输给所述保护装置，所述保护装置包括：获取部分、故障识别部分以及直流断路器分断操作控制部分；
    所述获取部分，配置为在直流线路保护系统启动的情况下，获取所述直流线路保护系统启动时刻前后的线路数据；
    所述故障识别部分，配置为根据所述线路数据进行故障区域识别；所述故障区域识别用于判断直流线路发生是否发生区内故障；在所述直流线路发生区内故障的情况下，进行故障干扰识别；所述故障干扰识别用于判断所述区内故障是真实故障还是干扰；在所述区内故障为真实故障的情况下，进行故障选极；
    所述直流断路器分断操作控制部分，配置为在所述直流线路发生区内故障的情况下，控制相应的直流断路器依次执行第一次换流操作和快速机械开关分闸操作；在所述区内故障为所述干扰的情况下，控制相应的直流断路器执行第一次换流复归操作；在所述区内故障为真实故障的情况下，控制相应的直流断路器执行第二次换流操作。
  6. 根据权利要求5所述的保护装置，其中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于主支路上的电力电子开关模块并导通位于转移支路上的电力电子开关模块，使得故障电流从所述主支路向所述转移支路转移；控制相应的直流断路器在所述故障电流从主支路全部转移到转移支路的情况下，执行所述快速机械开关分闸操作。
  7. 根据权利要求6所述的保护装置，其中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器关断位于所述转移支路上的电力电子模块，使得所述故障电流经二极管全桥对所述转移支路上的电力电子开关模块内的电容进行充电；
    其中，在所述转移支路上的电力电子模块内的电容电压大于耗能支路金属氧化物可变电阻MOV启动阈值电压的情况下，所述直流断路器的所述耗能支路导通，所述故障电流从所述转移支路向所述耗能支路转移。
  8. 根据权利要求6所述的保护装置，其中，所述直流断路器分断操作控制部分，还配置为控制相应的直流断路器执行快速机械开关合闸操作；控制相应的直流断路器导通位于主支路上的电力电子开关模块，并关断位于转移支路上的所有电力电子模块，使得线路电流从转移支路向主支路转移；其中，在所述线路电流全部从所述转移支路转移到所述主支路的情况下，所述直流断路器恢复正常运行。
  9. 一种保护装置，包括处理器和存储器，存储器存储了计算机程序，所述计算机程 序被调用以实现如权利要求1至4中任一项所述的方法对应的操作。
  10. 一种保护系统，包括测量装置、如权利要求5至8中任一项所述的保护装置和直流断路器，基于就地化保护原则，所述保护装置与所述测量装置、直流断路器直接连接。
  11. 根据权利要求10所述的保护系统，其中，所述保护装置与所述直流断路器的数量相等，且一一对应。
  12. 根据权利要求10所述的保护系统，其中，所述直流断路器为混合式直流断路器。
  13. 一种计算机存储介质，所述存储介质中存储计算机程序，所述计算机程序被处理器调用以执行如权利要求1至4中任一项所述的方法对应的操作。
  14. 一种计算机程序产品，所述计算机程序产品包括计算机程序或指令，在所述计算机程序或指令在计算机上运行的情况下，使得所述计算机执行权利要求1至4中任一所述的方法。
PCT/CN2022/135112 2021-11-30 2022-11-29 基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置、系统、计算机存储介质和计算机程序产品 WO2023098681A1 (zh)

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JP2011055685A (ja) * 2009-09-04 2011-03-17 Railway Technical Res Inst 超電導直流き電システム、および故障検出方法
CN108054736A (zh) * 2017-11-27 2018-05-18 山东大学 一种基于电压极波的多端柔性直流电网直流线路保护方法
CN113078619A (zh) * 2021-04-12 2021-07-06 中国矿业大学 一种柔性直流电网快速保护方法
CN114825284A (zh) * 2021-11-30 2022-07-29 长沙理工大学 一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置及其系统

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CN108054736A (zh) * 2017-11-27 2018-05-18 山东大学 一种基于电压极波的多端柔性直流电网直流线路保护方法
CN113078619A (zh) * 2021-04-12 2021-07-06 中国矿业大学 一种柔性直流电网快速保护方法
CN114825284A (zh) * 2021-11-30 2022-07-29 长沙理工大学 一种基于直流断路器前摄预动的柔性直流电网故障线路隔离方法、保护装置及其系统

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