WO2024045962A1 - 高压直流线路保护的方法及系统 - Google Patents

高压直流线路保护的方法及系统 Download PDF

Info

Publication number
WO2024045962A1
WO2024045962A1 PCT/CN2023/109542 CN2023109542W WO2024045962A1 WO 2024045962 A1 WO2024045962 A1 WO 2024045962A1 CN 2023109542 W CN2023109542 W CN 2023109542W WO 2024045962 A1 WO2024045962 A1 WO 2024045962A1
Authority
WO
WIPO (PCT)
Prior art keywords
line
voltage
fault
mode
mode fault
Prior art date
Application number
PCT/CN2023/109542
Other languages
English (en)
French (fr)
Inventor
李小鹏
滕予非
刘磊
喻悦箫
牟大林
林圣�
张华杰
Original Assignee
国网四川省电力公司电力科学研究院
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 国网四川省电力公司电力科学研究院 filed Critical 国网四川省电力公司电力科学研究院
Publication of WO2024045962A1 publication Critical patent/WO2024045962A1/zh

Links

Classifications

    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Definitions

  • This application relates to the technical field of high-voltage DC line protection, for example, to methods and systems for high-voltage DC line protection.
  • High-voltage DC transmission technology is widely used due to its advantages such as large transmission capacity, long transmission distance, and low loss.
  • High-voltage DC transmission lines have the characteristics of long transmission distance, large transmission capacity, and complex operating environment.
  • overhead lines are used as the medium for power transmission.
  • actual operating conditions show that HVDC transmission lines are extremely prone to short-circuit faults and are one of the equipment with the highest failure rate in HVDC transmission systems. Therefore, research on highly sensitive and reliable HVDC transmission line protection methods is crucial to ensure the safe and stable operation of HVDC transmission systems.
  • traveling wave protection is used as the main protection of high-voltage DC transmission lines.
  • the mutation amount and voltage change rate of voltage and current waves are used as characteristic quantities to detect DC transmission line faults. It has the advantage of fast fault detection speed.
  • actual on-site operation conditions show that as the fault transition resistance of high-voltage DC transmission lines increases, the voltage and current amplitudes in the line will decrease, resulting in a weak change in the total characteristic quantity in the traveling wave protection criterion, which is not conducive to fault identification. .
  • the protection sensitivity is insufficient, resulting in a certain risk of failure in traveling wave protection.
  • the technical problem to be solved by this application is: to improve the ability of high-voltage DC transmission line traveling wave protection to withstand transition resistance and reduce the risk of traveling wave protection failure; this application provides a method and system for high-voltage DC line protection, based on DC line parameters and DC The single-terminal protection method in which the system operating parameters compensate for the line mode fault voltage eliminates the impact of transition resistance on the line mode fault voltage and improves the sensitivity of the protection action.
  • the line mode fault voltage is compensated based on the DC line parameters, the DC system operating parameters and the first peak value of the line mode fault voltage;
  • a high-voltage DC line protection system including: an acquisition module, a calculation module, a first determination module, a compensation module and a second determination module;
  • the acquisition module is configured to obtain DC line parameters and DC system operating parameters, and sample operating parameters at the DC line protection installation location;
  • the calculation module is configured to calculate the line mode fault voltage, zero mode fault voltage, line mode fault current and the continuous change rate of the line mode fault current at the sampling point based on the operating parameters at the DC line protection installation;
  • the first determination module is configured to determine whether to activate line protection based on the line mode fault current and the continuous change rate of the line mode fault current;
  • the compensation module is configured to compensate the line mode fault voltage based on the DC line parameters, the DC system operating parameters and the first peak value of the line mode fault voltage in response to activating the line protection;
  • the second determination module is configured to determine whether a fault occurs in the high-voltage DC line based on the compensated line mode fault voltage; in response to a fault in the high-voltage DC line, determine the polarity of the line fault based on the zero-mode fault voltage.
  • An electronic device including:
  • a storage device configured to store at least one program
  • the at least one processor When the at least one program is executed by the at least one processor, the at least one processor is caused to implement the above-mentioned method for protecting a high-voltage DC line.
  • a computer-readable storage medium which stores a computer program.
  • the program is executed by a processor, the above-mentioned method for protecting a high-voltage DC line is implemented.
  • Figure 1 is a schematic flow chart of a high-voltage DC line protection method provided by an embodiment of the present application
  • Figure 2 is a schematic structural diagram of a high-voltage DC line protection system provided by an embodiment of the present application
  • Figure 3A is a bipolar full-voltage operation mode of a high-voltage direct current transmission system provided by an embodiment of the present application. Schematic;
  • Figure 3B is a schematic diagram of a bipolar structure of a high-voltage direct current transmission system in low-valve half-pressure operation provided by an embodiment of the present application;
  • Figure 4A is a schematic diagram of the rectifier side line mode fault voltage component before and after compensation when a fault occurs at the 100km position of the DC line in a bipolar full-voltage operation mode provided by the embodiment of the present application;
  • Figure 4B is a schematic diagram of the rectifier side line mode fault voltage component before and after compensation when a fault occurs at the 1000km position of the DC line in a bipolar full-voltage operation mode provided by the embodiment of the present application;
  • Figure 5 is a schematic diagram of the inverter side line mode fault voltage component before and after compensation when a fault occurs at 1500km of the DC line under bipolar low-valve half-voltage operation provided by the embodiment of the present application;
  • Figure 6A is a schematic diagram of the rectifier side line mode fault voltage component before and after compensation when the DC line forward fault occurs outside the area in a bipolar full-voltage operation mode provided by the embodiment of the present application;
  • Figure 6B is a schematic diagram of the rectifier side line mode fault voltage component before and after compensation when a DC line reverse fault occurs outside the reverse zone in a bipolar full-voltage operation mode provided by the embodiment of the present application;
  • FIG. 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.
  • This application takes the UHV hybrid cascade DC transmission project as the object to verify the protection method.
  • This project proposes for the first time the use of grid-commutated converter (Line-Commutated Converter, LCC) in the rectifier station.
  • LCC grid-commutated converter
  • MMC modular multilevel converters
  • parallel hybrid DC transmission structure which makes full use of the advantages of current source LCC and voltage source MMC transmission, and has important application value in improving system operation economy, control flexibility, and receiving-end power grid stability.
  • This application uses the following embodiments to solve the technical problem of the single-ended traveling wave protection method having weak changes in electrical quantity characteristics during high resistance faults and insufficient traveling wave protection sensitivity.
  • FIG. 1 is a schematic flowchart of a method for protecting a high-voltage DC line provided by an embodiment of the present application. The method includes S1-S5.
  • S1 obtain the DC line parameters and DC system operating parameters, and sample the operating parameters of the DC line protection installation location.
  • the DC line parameters include: DC line length L, DC line inductance per unit length L 0 , DC Capacitance per unit length of the line C 0 , resistance per unit length of the DC line R 0 , conductance per unit length of the DC line G 0 , DC line line mode wave impedance Z c1 , DC line zero mode wave impedance Z c0 , DC line traveling wave line mode
  • the attenuation coefficient k a1 and the distortion coefficient ⁇ a1 of the component unit length line are examples of the component unit length line.
  • the operating parameters of the DC system include: DC voltage U r when the rectifier side of the DC system is operating normally, and DC voltage U i when the inverter side of the DC system is operating normally.
  • S2 includes S21-S23:
  • the positive voltage component of , i n (kn 0 ) is the negative current component of n 0 sampling points before sampling point k
  • u n (kn 0 ) is the negative voltage component of n 0 sampling points before sampling point k.
  • Determine whether to activate line protection based on the line mode fault current and the continuous change rate of the line mode fault current include:
  • Line protection start criteria Criterion 1, ⁇ i 1 (k) > ⁇ i 1set ; where ⁇ i 1set is the line mode fault current Over-limit start threshold; criterion 2, When criterion 1 and criterion 2 are both satisfied, line protection is started, and the corresponding sampling point when line protection is started is recorded as k s , the fault time t s is k s T s and enters S4.
  • the line mode fault current over-limit start-up threshold ⁇ i 1set is 0.01pu.
  • the line mode fault voltage is compensated based on the DC line parameters, DC system operating parameters and the first peak value of the line mode fault voltage.
  • S4 includes S41-S45:
  • the criterion for the internal and external faults of the DC line is constructed with the compensated line mode fault voltage u 1comp (k): criterion a,
  • > ⁇ set2 ; among them, ⁇ set2 is the setting value in the DC line fault area value; criterion c, k comp ⁇ k rel ⁇ k set ; where k rel is the reliability coefficient, k set is the compensation coefficient when a grounding resistance R f 500 ⁇ ground fault occurs at the end of the DC line, R f is 500 ⁇ ; when the criterion When criterion a, criterion b, and criterion c are all satisfied, it is determined that the high-voltage DC line has
  • Determining line fault polarity based on zero-mode fault voltage includes:
  • the fault polarity criterion is constructed based on the zero-mode fault voltage ⁇ u 0 (k s ): when ⁇ u 0 (k s )>u 0set , the line fault polarity is determined to be a positive fault; when ⁇ u 0 (k s ) ⁇ - In the case of u 0set , it is determined that the polarity of the line fault is a negative pole fault; in the case of -u 0set ⁇ u 0 (k s ) ⁇ u 0set , it is determined that the polarity of the line fault is a bipolar fault; where u 0set is the fault pole
  • the judgment threshold is set according to the maximum unbalanced voltage when a bipolar fault occurs on the high-voltage DC line.
  • the high-voltage DC line protection method provided by the embodiments of this application only needs to use the voltage and current wave information at the single-end measurement point of the DC line as fault criteria, avoiding the high communication delay problem caused by long lines and protecting actions.
  • the speed is fast; the relationship between the line mode fault voltage and the transition resistance is used to compensate the line mode fault voltage when a DC line fault occurs, eliminating the influence of the transition resistance on the line mode fault voltage and improving the sensitivity of the protection action; using the line mode
  • the dual criteria of fault current and continuous change rate of line mode fault current are used as the line protection start-up criteria, which reduces the impact of noise and other external interference factors on protection start-up.
  • this embodiment provides a high-voltage DC line protection system, including: acquisition mode Block 10, calculation module 20, first determination module 30, compensation module 40 and second determination module 50; the acquisition module 10 is configured to obtain DC line parameters and DC system operating parameters, and sample the operating parameters of the DC line protection installation location;
  • the calculation module 20 is configured to calculate the line mode fault voltage, the zero mode fault voltage, the line mode fault current and the continuous change rate of the line mode fault current at the sampling point based on the operating parameters of the DC line protection installation; the first determination module 30
  • the compensation module 40 is configured to determine whether to activate line protection based on the line mode fault current and the continuous change rate of the line mode fault current; the compensation module 40 is configured to respond to initiating line protection, based on the DC line parameters, DC system operating parameters and line mode fault voltage.
  • the first peak value compensates for the line mode fault voltage
  • the second determination module 50 is configured to determine whether the high-voltage DC line is faulty based on the compensated line-mode fault voltage; in response to a fault in the high-voltage DC line, the line is determined based on the zero-mode fault voltage The polarity of the fault.
  • the DC line parameters include: the total length of the DC line L, the inductance L 0 per unit length of the DC line, the capacitance C 0 per unit length of the DC line, the resistance R 0 per unit length of the DC line, and the resistance R 0 per unit length of the DC line.
  • the DC system operating parameters include: DC system rectifier side DC voltage U r , and DC system inverter side DC voltage U i ;
  • the operating parameters of the DC line protection installation include: positive DC voltage u p (k), negative DC voltage u n (k), positive pole DC current i p (k) and negative DC current in (k), where the sampling period T s and k represent a sequence of discrete sampling points.
  • the computing module 20 is configured as:
  • the positive voltage component of the n 0 sampling points, in (kn 0 ) is the negative current component of the n 0 sampling points before the sampling point k, and u n (kn 0 ) is the n before the sampling point k.
  • the first determination module 30 is configured as:
  • Line protection start criteria Criterion 1, ⁇ i 1 (k) > ⁇ i 1set ; where ⁇ i 1set is the line mode fault current Over-limit start threshold; criterion 2, When both criterion 1 and criterion 2 are satisfied, the line protection is started, and the corresponding sampling point when the line protection is started is recorded as k s , and the fault time t s is k s T s .
  • the system also includes a return execution module.
  • the return execution module is configured to: when at least one of the criterion 1 and the criterion 2 is not satisfied, it is determined that the high-voltage DC line has not failed, and the return execution module is configured to: Execute the operations of obtaining the DC line parameters and DC system operating parameters, and sampling the operating parameters of the DC line protection installation location.
  • the line mode fault current over-limit activation threshold ⁇ i 1set is 0.01pu.
  • the compensation module 40 is configured as:
  • u 1max max([ ⁇ u 1 (k s ), ⁇ u 1 (k s +60)])
  • the compensation coefficient k comp for calculating the line mode fault voltage is:
  • the second determination module 50 is configured to determine whether a fault occurs in the high-voltage DC line based on the compensated line mode fault voltage in the following manner:
  • the criterion for the internal and external faults of the DC line is constructed with the compensated line mode fault voltage u 1comp (k): criterion a,
  • ⁇ set1 is 0.08125pu
  • ⁇ set2 is 0.125pu
  • the second determination module 50 is configured to determine the line fault polarity based on the zero-mode fault voltage in the following manner:
  • the fault polarity criterion is constructed based on the zero-mode fault voltage ⁇ u 0 (k s ): when ⁇ u 0 (k s ) > u 0set , the line fault polarity is determined to be a positive fault; when ⁇ u 0 (k s ) In the case of ⁇ -u 0set , it is determined that the polarity of the line fault is a negative pole fault; in the case of -u 0set ⁇ u 0 (k s ) ⁇ u 0set , it is determined that the polarity of the line fault is a bipolar fault; where , u 0set is the fault polarity determination threshold, which is set according to the maximum unbalanced voltage when a bipolar fault occurs on a high-voltage DC line.
  • the high-voltage DC line protection system provided by the embodiments of this application can execute the high-voltage DC line protection method provided by any embodiment of this application, and has functional modules and effects corresponding to the execution method.
  • the Power Systems Computer Aided Design/Electromagnetic Transients including Direct Current (PSCAD/EMTDC) simulation software was used to build a The bipolar simulation model of the high-voltage direct current transmission system's full-voltage operation shown in Figure 3A, and the bipolar simulation model of the high-voltage direct current transmission system's low-valve half-voltage operation shown in Figure 3B.
  • Full pressure In the bipolar simulation model of the operating mode, the rectifier station at any pole uses dual 12-pulse LCCs in series, the high-voltage side of the inverter station has a single 12-pulse LCC, and the low-voltage side uses three MMCs in parallel.
  • the rectifier station of any pole adopts a single 12-pulse LCC
  • the inverter station adopts three parallel MMCs on the low-voltage side.
  • the DC line adopts a frequency variable parameter model, and the total length of the line is set to 2086km.
  • a 150mH smoothing reactor is connected in series between the outlet end of the LCC converter and the DC line, and between the ground electrode and the LCC converter.
  • f 1 represents the fault within the DC line area
  • f 2 and f 3 represent the reverse and forward faults outside the DC line area respectively.
  • Figure 4A is a schematic diagram of the rectifier side line mode fault voltage component before and after compensation when a fault occurs at the 100km position of the DC line in a bipolar full-voltage operation mode provided by the embodiment of the present application.
  • Figure 4B is a schematic diagram provided by the embodiment of the present application. Schematic diagram of the rectifier side line mode fault voltage component before and after compensation when a fault occurs at the 1000km position of the DC line in the bipolar full voltage operation mode.
  • the values of the fault resistance R f in Figure 4A and Figure 4B are 0, 50, 100, 200, and 500 ⁇ respectively.
  • the amplitude of the compensated line mode fault voltage component decreases as the transition resistance increases; the amplitude of the compensated line mode fault voltage component does not change as the transition resistance increases. It can be seen from the compensation results that as the transition resistance increases, the compensation coefficient also increases; as the fault distance increases, the growth rate of the line mode fault voltage becomes slower, and the time for the line mode fault voltage to reach the peak value also increases. At the same time, the compensated line mode fault voltages under different transition resistances completely overlap, indicating that there is a linear relationship between the transition resistance and the line mode fault voltage. After compensation, the line mode fault voltage amplitude is the same as the line mode fault voltage at the midpoint of the line. The mode fault voltage amplitudes are equal, which reduces the impact of transition resistance on the sensitivity of traveling wave protection.
  • Figure 5 is a schematic diagram of the inverter side line mode fault voltage component before and after compensation when a DC line fault occurs at 1500km under bipolar low valve half-voltage operation provided by the embodiment of the present application.
  • Figure 6A is a schematic diagram provided by the embodiment of the present application.
  • Figure 6B is a DC line under a bipolar full-voltage operation mode provided by an embodiment of the present application. Schematic diagram of the rectifier side line mode fault voltage component before and after compensation when the line fault occurs outside the reverse zone.
  • the values of fault resistance R f in Figure 5, Figure 6A and Figure 6B are 0, 50, 100, 200 and 500 ⁇ respectively.
  • the full-voltage bipolar DC positive line is set at 100, 700, 1000, 1200, and 2000km, and the negative line is set to ground at 1000km.
  • the ground resistance R f 100 ⁇
  • the fault identification simulation results are obtained as shown in Table 1. Among them, P represents the positive line, N represents the negative line, and "f 1 -P-100" means that the positive DC line fails 100km away from the rectifier side.
  • FIG. 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Referring now to FIG. 7 , a schematic structural diagram of an electronic device 500 suitable for implementing embodiments of the present application is shown. The electronic device 500 shown in FIG. 7 is only an example and should not impose any restrictions on the functions and usage scope of the embodiments of the present application.
  • the electronic device 500 may include a processing device (such as a central processing unit, a graphics processor, etc.) 501, which may process data according to a program stored in a read-only memory (Read-Only Memory, ROM) 502 or from a storage device. 508 loads the program in the random access memory (Random Access Memory, RAM) 503 to perform various appropriate actions and processes. In the RAM 503, various programs and data required for the operation of the electronic device 500 are also stored.
  • the processing device 501, ROM 502 and RAM 503 are connected to each other via a bus 504.
  • An input/output (I/O) interface 505 is also connected to bus 504.
  • input devices 506 including, for example, a touch screen, touch pad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; including, for example, a Liquid Crystal Display (LCD) , an output device 507 such as a speaker, a vibrator, etc.; a storage device 508 including a magnetic tape, a hard disk, etc.; and a communication device 509.
  • Communication device 509 may allow electronic device 500 to communicate wirelessly or wiredly with other devices to exchange data.
  • FIG. 7 illustrates electronic device 500 with various means, implementation or availability of all illustrated means is not required. More or fewer means may alternatively be implemented or provided.
  • the process described above with reference to the flowchart may be implemented as a computer software program.
  • embodiments of the present application include a computer program product including a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the method illustrated in the flowchart.
  • the computer program may be downloaded and installed from the network via communication device 509, or from storage device 508, or from ROM 502.
  • the processing device 501 When the computer program is executed by the processing device 501, the above functions defined in the method of this embodiment are performed.
  • the electronic equipment provided by the embodiments of the present application and the high-voltage DC line protection method provided by the above-mentioned embodiments belong to the same concept.
  • Technical details that are not described in detail in this embodiment can be referred to the above-mentioned embodiments, and And this embodiment has the same effect as the above-mentioned embodiment.
  • Embodiments of the present application provide a computer storage medium on which a computer program is stored.
  • the program is executed by a processor, the method for protecting high-voltage DC lines provided in the above embodiments is implemented.
  • the computer-readable medium mentioned above in this application may be a computer-readable signal medium or a computer-readable storage medium, or any combination of the above two.
  • the computer-readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof.
  • Examples of computer readable storage media may include: an electrical connection having one or more wires, a portable computer disk, a hard drive, RAM, ROM, Erasable Programmable Read-Only Memory (EPROM, or flash memory) , optical fiber, portable compact disk read-only memory (Compact Disc Read-Only Memory, CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the above.
  • a computer-readable storage medium may be any tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device.
  • the computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, in which computer-readable program code is carried. Such propagated data signals may take many forms, including electromagnetic signals, optical signals, or any suitable combination of the above.
  • a computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device .
  • Program code embodied on a computer-readable medium can be transmitted using any appropriate medium, including: wire, optical cable, radio frequency (Radio Frequency, RF), etc., or any suitable combination of the above.
  • the client and server can communicate using any currently known or future developed network protocol, such as HyperText Transfer Protocol (HTTP), and can communicate with digital data in any form or medium.
  • HTTP HyperText Transfer Protocol
  • Communications e.g., communications network
  • Examples of communication networks include Local Area Networks (LANs), Wide Area Networks (WANs), the Internet (e.g., the Internet), and end-to-end networks (e.g., ad hoc end-to-end networks), as well as any current network for knowledge or future research and development.
  • LANs Local Area Networks
  • WANs Wide Area Networks
  • the Internet e.g., the Internet
  • end-to-end networks e.g., ad hoc end-to-end networks
  • the above-mentioned computer-readable medium may be included in the above-mentioned electronic device; it may also exist independently without being assembled into the electronic device.
  • Computer program code for performing the operations of the present application may be written in one or more programming languages, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional Procedural programming language—such as "C" or a similar programming language.
  • the program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on a remote computer or server.
  • the remote computer may be connected to the user computer through any kind of network, including a LAN or WAN, or may be connected to an external computer (eg, through the Internet using an Internet service provider).
  • each block in the flowchart or block diagram may represent a module, segment, or portion of code that contains one or more logic functions that implement the specified executable instructions.
  • the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown one after another may actually execute substantially in parallel, or they may sometimes execute in the reverse order, depending on the functionality involved.
  • each block of the block diagram and/or flowchart illustration, and combinations of blocks in the block diagram and/or flowchart illustration can be implemented by special purpose hardware-based systems that perform the specified functions or operations. , or can be implemented using a combination of specialized hardware and computer instructions.
  • exemplary types of hardware logic components include: field programmable gate array (Field Programmable Gate Array, FPGA), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), application specific standard product (Application Specific Standard Parts (ASSP), System on Chip (SOC), Complex Programming Logic Device (CPLD), etc.
  • a machine-readable medium may be a tangible medium that may contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.
  • the machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium.
  • Machine-readable media may include electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices, or any suitable combination of the foregoing. Examples of machine-readable storage media would include an electrical connection based on one or more wires, a portable computer disk, a hard drive, RAM, ROM, EPROM or flash memory, optical fiber, CD-ROM, optical storage device, magnetic storage device, or Any suitable combination of the above.

Landscapes

  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

高压直流线路保护的方法及系统。高压直流线路保护的方法包括：获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数(S1)；基于直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和线模故障电流的连续变化率(S2)；根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护(S3)；响应于启动线路保护，基于直流线路参数、直流系统运行参数和线模故障电压的首峰值对线模故障电压进行补偿(S4)；根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于高压直流线路发生故障，基于零模故障电压判断线路故障极性(S5)。

Description

高压直流线路保护的方法及系统
本申请要求在2022年08月31日提交中国专利局、申请号为202211052988.7的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本申请涉及高压直流线路保护技术领域，例如涉及高压直流线路保护的方法及系统。
背景技术
高压直流输电技术因其输电容量大、输电距离长、损耗低等优点而被广泛使用。高压直流输电线路具有输电距离远、输送容量大、运行环境复杂等特点，一般采用架空线作为电能传输的媒介。然而，实际运行情况表明，高压直流输电线路极易发生短路故障，是高压直流输电系统中故障率最高的设备之一。因此，研究高灵敏度和可靠性的高压直流输电线路保护方法对确保高压直流输电系统的安全稳定运行至关重要。
在实际工程中，行波保护作为高压直流输电线路的主保护，以电压、电流行波的突变量和电压变化率作为检测直流输电线路故障的特征量，具有故障检测速度快的优点。然而，根据现场实际运行情况表明，随着高压直流输电线路故障过渡电阻的增加，线路中的电压、电流幅值都会降低，导致行波保护判据中总特征量变化微弱，不利于故障的辨识。当高压直流输电线路发生高阻故障时保护灵敏度不足，导致行波保护存在一定的拒动风险。
发明内容
本申请所要解决的技术问题是：提升高压直流输电线路行波保护耐受过渡电阻的能力，降低行波保护拒动风险；本申请提供高压直流线路保护的方法及系统，基于直流线路参数和直流系统运行参数对线模故障电压进行补偿的单端量保护方法，消除了过渡电阻对线模故障电压的影响，提高了保护动作的灵敏性。
提供一种高压直流线路保护的方法，包括：
获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数；
基于直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障 电压、线模故障电流和线模故障电流的连续变化率；
根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护；
响应于启动线路保护，基于直流线路参数、直流系统运行参数和线模故障电压的首峰值对线模故障电压进行补偿；
根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于高压直流线路发生故障，基于零模故障电压判断线路故障极性。
还提供一种高压直流线路保护的系统，包括：采集模块、计算模块、第一判定模块、补偿模块和第二判定模块；
所述采集模块设置为获取直流线路参数和直流系统运行参数，并采样直流线路保护安装处运行参数；
所述计算模块设置为基于直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和线模故障电流的连续变化率；
所述第一判定模块设置为根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护；
所述补偿模块设置为响应于启动线路保护，基于直流线路参数、直流系统运行参数和线模故障电压的首峰值对线模故障电压进行补偿；
所述第二判定模块设置为根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于高压直流线路发生故障，基于零模故障电压判断线路故障的极性。
还提供一种电子设备，包括：
至少一个处理器；
存储装置，设置为存储至少一个程序；
当所述至少一个程序被所述至少一个处理器执行，使得所述至少一个处理器实现上述的高压直流线路保护的方法。
还提供一种计算机可读存储介质，存储有计算机程序，所述程序被处理器执行时实现上述的高压直流线路保护的方法。
附图说明
图1为本申请实施例提供的一种高压直流线路保护的方法的流程示意图；
图2为本申请实施例提供的一种高压直流线路保护的系统的结构示意图；
图3A为本申请实施例提供的一种高压直流输电系统全压运行方式的双极 结构示意图；
图3B为本申请实施例提供的一种高压直流输电系统低阀半压运行方式的双极结构示意图；
图4A为本申请实施例提供的一种双极全压运行方式下直流线路100km位置发生故障时整流侧线模故障电压分量的补偿前与补偿后示意图；
图4B为本申请实施例提供的一种双极全压运行方式下直流线路1000km位置发生故障时整流侧线模故障电压分量的补偿前与补偿后示意图；
图5为本申请实施例提供的一种双极低阀半压运行下直流线路1500km处发生故障时逆变侧线模故障电压分量的补偿前与补偿后示意图；
图6A为本申请实施例提供的一种双极全压运行方式下直流线路正向区外故障时整流侧线模故障电压分量的补偿前与补偿后示意图；
图6B为本申请实施例提供的一种双极全压运行方式下直流线路反向区外故障时整流侧线模故障电压分量的补偿前与补偿后示意图；
图7为本申请实施例提供的一种电子设备的结构示意图。
具体实施方式
下面结合实施例和附图，对本申请进行说明，本申请的示意性实施方式及其说明仅用于解释本申请。
本申请以特高压混合级联直流输电工程作为验证保护方法的对象。该工程首次提出在整流站采用电网换相换流器(Line-Commutated Converter，LCC)，逆变站高压端采用LCC、低压端采用3个模块化多电平换流器(Modular Multilevel Converter，MMC)并联的新型混合直流输电结构，其充分利用了电流源LCC和电压源MMC输电的优点，在提高系统运行经济性、控制灵活性、受端电网稳定性等方面具有重要的应用价值。
本申请通过以下实施例解决单端行波保护方法在高阻故障时电气量特征变化微弱，行波保护灵敏度不足的技术问题。
实施例一
本实施例提供一种高压直流线路保护的方法，图1为本申请实施例提供的一种高压直流线路保护的方法的流程示意图，该方法包括S1-S5。
S1，获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数。
直流线路参数包括：直流线路长度L，直流线路单位长度的电感L0、直流 线路单位长度的电容C0、直流线路单位长度的电阻R0、直流线路单位长度的电导G0、直流线路线模波阻抗Zc1、直流线路零模波阻抗Zc0、直流线路行波线模分量单位长度线路的衰减系数ka1和畸变系数τa1。
直流系统运行参数包括：直流系统整流侧正常运行时直流电压Ur、和直流系统逆变侧正常运行时直流电压Ui。
直流线路保护安装处运行参数包括：正极直流电压up(k)、负极直流电压un(k)、正极直流电流ip(k)和负极直流电流in(k)，采样周期Ts，k表示离散采样点序列；采样周期Ts＝0.01ms，k＝3001,3002,3003…；
S2，基于直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和线模故障电流的连续变化率。
S2包括S21-S23：
S21，基于直流线路保护安装处运行参数计算采样点k的正极线路故障电流分量Δip(k)＝ip(k)-ip(k-n0)，负极线路故障电流分量Δin(k)＝in(k)-in(k-n0)，正极线路故障电压分量Δup(k)＝up(k)-up(k-n0)，负极线路故障电压分量Δun(k)＝un(k)-un(k-n0)；ip(k-n0)为采样点k前的n0个采样点的正极电流分量，up(k-n0)为采样点k前的n0个采样点的正极电压分量，in(k-n0)为采样点k前的n0个采样点的负极电流分量，un(k-n0)为采样点k前的n0个采样点的负极电压分量。
S22，对正极线路故障电流分量和负极线路故障电流分量进行相模变换得到采样点k的线模故障电流Δi1(k)：
对正极线路故障电压分量和负极线路故障电压分量进行相模变换得到采样点k的零模故障电压Δu0(k)和线模故障电压Δu1(k)：
S23，计算采样点k的线模故障电流Δi1(k)在采样点k后连续3个采样点的变化率：
S3，根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护。
根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护， 包括：
用线模故障电流越限启动与线模故障电流的连续变化率启动双重判据作为线路保护启动判据：判据1，Δi1(k)＞Δi1set；其中，Δi1set为线模故障电流越限启动阈值；判据2，当判据1与判据2均被满足时，启动线路保护，并记录启动线路保护时对应的采样点为ks，故障时刻ts为ksTs并进入S4。
在判据1与判据2中的至少之一未被满足的情况下，确定高压直流线路未发生故障，返回执行S1。
线模故障电流越限启动阈值Δi1set为0.01pu。
S4，响应于启动线路保护，基于直流线路参数、直流系统运行参数和线模故障电压的首峰值对线模故障电压进行补偿。
S4包括S41-S45：
S41，计算直流系统正常运行时高压直流线路中点位置xmid处的直流电压Ufmid：
S42，计算直流线路中点位置xmid处发生接地电阻Rf的接地故障时保护安装处的线模故障电压分量u1mid：
Rf＝0Ω
计算线路保护动作后线模故障电压分量u1mid在60个采样点中的最大值u1midmax，并将线模故障电压分量u1midmax作为补偿参考值。
S43，在高压直流线路任意位置x km处发生故障时，计算线路保护动作后线模故障电压Δu1(k)在60个采样点中的最大值u1max，记录u1max对应的采样点为kmax，u1max对应到达时刻tu1max为kmaxTs，u1max表示为：
u1max＝max([Δu1(ks)，Δu1(ks+60)])。
S44，在高压直流线路任意位置x km处发生故障时，计算线模故障电压的 补偿系数kcomp为：
S45，在采样点区间[ks,ks+kmax]中，将每个采样点对应的线模故障电压均乘以补偿系数kcomp，得到补偿后的线模故障电压u1comp[kmax-ks+1]：
u1comp[kmax-ks+1]＝kcomp·(Δu1(ks),Δu1(ks+1),···,Δu1(ks+kmax))。
S5，根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于高压直流线路发生故障，基于零模故障电压判断线路故障极性。
根据补偿后的线模故障电压判断高压直流线路是否发生故障，包括：
以补偿后的线模故障电压u1comp(k)构造直流线路内外故障的判据：判据a，|u1comp(ks+1)|-|u1comp(ks)|＞Δset1；其中，Δset1是直流线路故障区内整定值；判据b，|u1comp(ks+2)|-|u1comp(ks)|＞Δset2；其中，Δset2是直流线路故障区内整定值；判据c，kcomp＜krel·kset；其中，krel为可靠系数，kset为直流线路末端发生接地电阻Rf＝500Ω接地故障时的补偿系数，Rf为500Ω；当判据a、判据b和判据c均被满足时，判定高压直流线路发生故障；当判据a、判据b和判据c中的至少之一未被满足时，判定高压直流线路未发生故障。
基于零模故障电压判断线路故障极性，包括：
以零模故障电压Δu0(ks)构造故障极性判据：在Δu0(ks)＞u0set的情况下，判定线路故障极性为正极故障；在Δu0(ks)＜-u0set的情况下，判定线路故障极性为负极故障；在-u0set＜Δu0(ks)＜u0set的情况下，判定线路故障极性为双极故障；其中，u0set为故障极性判定阈值，按照高压直流线路发生双极故障时的最大不平衡电压进行整定。
本申请实施例提供的高压直流线路保护的方法，仅需利用直流线路单端测量点的电压、电流行波信息作为故障判据，避免了因线路较长导致的高通信延时问题，保护动作速度快；利用直流线路故障时线模故障电压与过渡电阻之间的关系对线模故障电压进行补偿，消除了过渡电阻对线模故障电压的影响，提高了保护动作的灵敏性；利用线模故障电流和线模故障电流的连续变化率双重判据作为线路保护启动判据，降低了噪声等外界干扰因素对保护启动的影响。
实施例二
如图2所示，本实施例提供一种高压直流线路保护的系统，包括：采集模 块10、计算模块20、第一判定模块30、补偿模块40和第二判定模块50；所述采集模块10设置为获取直流线路参数和直流系统运行参数，并采样直流线路保护安装处运行参数；所述计算模块20设置为基于直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和线模故障电流的连续变化率；所述第一判定模块30设置为根据线模故障电流和线模故障电流的连续变化率判断是否启动线路保护；所述补偿模块40设置为响应于启动线路保护，基于直流线路参数、直流系统运行参数和线模故障电压的首峰值对线模故障电压进行补偿；所述第二判定模块50设置为根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于高压直流线路发生故障，基于零模故障电压判断线路故障的极性。
一实施例中，所述直流线路参数包括：直流线路总长度L，直流线路单位长度的电感L0、直流线路单位长度的电容C0、直流线路单位长度的电阻R0、直流线路单位长度的电导G0、直流线路线模波阻抗Zc1、直流线路零模波阻抗Zc0、直流线路单位长度的线模衰减系数ka1和线模色散时间常数τa1；所述直流系统运行参数包括：直流系统整流侧直流电压Ur、和直流系统逆变侧直流电压Ui；所述直流线路保护安装处运行参数包括：正极直流电压up(k)、负极直流电压un(k)、正极直流电流ip(k)和负极直流电流in(k)，其中，采样周期Ts，k表示离散采样点序列。
一实施例中，计算模块20设置为：
基于所述直流线路保护安装处运行参数计算采样点k的正极线路故障电流分量Δip(k)＝ip(k)-ip(k-n0)，负极线路故障电流分量Δin(k)＝in(k)-in(k-n0)，正极线路故障电压分量Δup(k)＝up(k)-up(k-n0)，负极线路故障电压分量Δun(k)＝un(k)-un(k-n0)；其中，ip(k-n0)为所述采样点k前的n0个采样点的正极电流分量，up(k-n0)为所述采样点k前的n0个采样点的正极电压分量，in(k-n0)为所述采样点k前的n0个采样点的负极电流分量，un(k-n0)为所述采样点k前的n0个采样点的负极电压分量；
对所述正极线路故障电流分量和所述负极线路故障电流分量进行相模变换得到所述采样点k的线模故障电流Δi1(k)：
对所述正极线路故障电压分量和所述负极线路故障电压分量进行相模变换得到所述采样点k的零模故障电压Δu0(k)和线模故障电压Δu1(k)：
计算所述采样点k的线模故障电流Δi1(k)在所述采样点k后连续3个采样点 的变化率：
一实施例中，第一判定模块30设置为：
用线模故障电流越限启动与线模故障电流的连续变化率启动双重判据作为线路保护启动判据：判据1，Δi1(k)＞Δi1set；其中，Δi1set为线模故障电流越限启动阈值；判据2，在所述判据1与所述判据2均被满足的情况下，启动所述线路保护，并记录启动线路保护时对应的采样点为ks，故障时刻ts为ksTs。
所述系统还包括返回执行模块，返回执行模块设置为：在所述判据1与所述判据2中的至少之一未被满足的情况下，确定所述高压直流线路未发生故障，返回执行所述获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数的操作。
一实施例中，所述线模故障电流越限启动阈值Δi1set为0.01pu。
一实施例中，补偿模块40设置为：
计算直流系统正常运行的情况下直流线路中点位置xmid处的直流电压Ufmid：

计算所述直流线路中点位置xmid处发生接地电阻Rf的接地故障时保护安装处的线模故障电压分量u1mid：
Rf＝0Ω
计算线路保护动作后线模故障电压分量u1mid在60个采样点中的最大值u1midmax，并将线模故障电压分量u1midmax作为补偿参考值；在所述高压直流线路一位置x km发生故障的情况下，计算线路保护动作后线模故障电压Δu1(k)在60个采样点中的最大值u1max，其中，记录u1max对应的采样点为kmax，u1max对应到达时刻tu1max为kmaxTs，u1max表示为：
u1max＝max([Δu1(ks)，Δu1(ks+60)])
在所述高压直流线路一位置x km处发生故障的情况下，计算线模故障电压的补偿系数kcomp为：
在采样点区间[ks,ks+kmax]中，将每个采样点对应的线模故障电压乘以补偿系数kcomp，得到补偿后的线模故障电压u1comp[kmax-ks+1]：
u1comp[kmax-ks+1]＝kcomp·(Δu1(ks),Δu1(ks+1),···,Δu1(ks+kmax))。
一实施例中，第二判定模块50设置为通过如下方式根据补偿后的线模故障电压判断高压直流线路是否发生故障：
以补偿后的线模故障电压u1comp(k)构造直流线路内外故障的判据：判据a，|u1comp(ks+1)|-|u1comp(ks)|＞Δset1；其中，Δset1是直流线路故障区内整定值；判据b，|u1comp(ks+2)|-|u1comp(ks)|＞Δset2；其中，Δset2是直流线路故障区内整定值；判据c，kcomp＜krel·kset；其中，krel为可靠系数，kset为直流线路末端发生接地电阻Rf接地故障时的补偿系数，Rf为500Ω；在所述判据a、所述判据b和所述判据c均被满足的情况下，判定所述高压直流线路发生故障；在所述判据a、所述判据b和所述判据c中的至少之一未被满足的情况下，判定所述高压直流线路未发生故障。
一实施例中，Δset1为0.08125pu，Δset2为0.125pu。
一实施例中，第二判定模块50设置为通过如下方式基于所述零模故障电压判断线路故障极性：
以零模故障电压Δu0(ks)构造故障极性判据：在Δu0(ks)＞u0set的情况下，判定所述线路故障极性为正极故障；在Δu0(ks)＜-u0set的情况下，判定所述线路故障极性为负极故障；在-u0set＜Δu0(ks)＜u0set的情况下，判定所述线路故障极性为双极故障；其中，u0set为故障极性判定阈值，按照高压直流线路发生双极故障时的最大不平衡电压进行整定。
本申请实施例所提供的高压直流线路保护的系统可执行本申请任意实施例所提供的高压直流线路保护的方法，具备执行方法相应的功能模块和效果。
实施例三
为验证本申请设计的高压直流线路保护的方法的正确性，利用电力系统计算机辅助设计/包含直流的电磁暂态(Power Systems Computer Aided Design/Electromagnetic Transients including Direct Current，PSCAD/EMTDC)仿真软件搭建了如图3A所示的高压直流输电系统全压运行方式的双极仿真模型、以及如图3B所示的高压直流输电系统低阀半压运行方式的双极仿真模型。全压 运行方式的双极仿真模型中任意一极的整流站采用双12脉动LCC串联，逆变站高压侧为单个12脉动LCC、低压侧采用三个MMC并联。低阀半压运行方式的双极仿真模型中任意一极的整流站采用单12脉动LCC，逆变站采用低压侧三个并联的MMC。直流线路采用频变参数模型，线路总长度设置为2086km，并在LCC换流器出线端与直流线路之间、接地极与LCC换流器之间各自串联连接150mH的平波电抗器。f1代表直流线路区内故障、f2、f3分别代表直流线路反向、正向区外故障。
图4A为本申请实施例提供的一种双极全压运行方式下直流线路100km位置发生故障时整流侧线模故障电压分量的补偿前与补偿后示意图，图4B为本申请实施例提供的一种双极全压运行方式下直流线路1000km位置发生故障时整流侧线模故障电压分量的补偿前与补偿后示意图。其中，图4A和图4B中故障电阻Rf取值分别为0、50、100、200、500Ω。从仿真结果可知，补偿前线模故障电压分量幅值随着过渡电阻的增大而减小；补偿后线模故障电压分量幅值随着过渡电阻的增大而不发生变化。从补偿结果可知，随着过渡电阻的增大，补偿系数也随之增加；随着故障距离的增大，线模故障电压增速变得缓慢，线模故障电压到达峰值的时间也有所增加。同时，不同过渡电阻情况下补偿后的线模故障电压完全重合，表明过渡电阻与线模故障电压之间呈线性关系，经过补偿后线模故障电压幅值与线路中点处金属性故障时线模故障电压幅值相等，降低了过渡电阻对行波保护灵敏度的影响。
图5为本申请实施例提供的一种双极低阀半压运行下直流线路1500km处发生故障时逆变侧线模故障电压分量的补偿前与补偿后示意图，图6A为本申请实施例提供的一种双极全压运行方式下直流线路正向区外故障时整流侧线模故障电压分量的补偿前与补偿后示意图，图6B为本申请实施例提供的一种双极全压运行方式下直流线路反向区外故障时整流侧线模故障电压分量的补偿前与补偿后示意图。其中，图5、图6A和图6B中故障电阻Rf取值分别为0、50、100、200、500Ω。在双极低阀半压运行下直流线路区内发生故障时，从仿真结果可以看出不同过渡电阻条件下补偿以后的线模故障电压完全重叠。在直流线路区外发生接地故障后，受平波电抗器和直流滤波器边界作用导致线模故障电压分量与过渡电阻不再满足线性关系，且经过补偿后线模故障电压分量的变化十分平缓。因此，通过补偿后的线模故障电压变化量的增量及补偿系数可直接进行直流线路区内外故障的判断。
为了验证所设计的高压直流线路保护的方法在不同位置发生接地故障时保护算法的适应性，分别设置全压双极直流正极线路100、700、1000、1200、2000km处，负极线路1000km处发生接地故障，接地电阻Rf＝100Ω，同时分别在正极线路正向区外和负极线路反向区外设置金属性接地故障(Rf＝0Ω)，在应用 本申请所设计的保护方法后，得到故障识别仿真结果如表1所示。其中P表示正极线路、N代表负极线路，其中“f1-P-100”表示正极直流线路距离整流侧100km处发生故障。
表1考虑不同故障位置的仿真结果
从表1的仿真结果可以看出，高压直流输电系统的内部故障和外部故障都可以通过所提出的方案正确检测出来。内部故障的最大补偿系数为2.02。但当直流电线的正向区外故障时，其补偿系数为6.21。对于发生在同一地点不同极的故障，补偿后的线模故障电压变化量是相同的，使用零模电压正确识别故障极性。
为了验证所设计的直流线路单端行波保护方法在不同故障过渡电阻情况下的耐受性能，设置了在双极全压运行方式下直流线路正极100km处和正向区外分别发生0、100、200、500Ω接地故障，得到故障识别仿真结果如表2所示。
表2考虑不同故障电阻的仿真结果
从表2仿真结果可知，在不同过渡电阻接地故障情况下，对于同一保护启动时刻，经过补偿后的线模故障电压与在相同位置故障后的线模故障电压差值相同，而对于不同的保护启动时刻，在不同的过渡电阻情况下，由于补偿系数是以保护启动后0.6ms内线模故障电压的最大值作为补偿对象，将导致补偿后的线模故障电压增量存在差异。仿真结果表明，利用补偿后的线模故障电压可以消除故障电阻的影响。
实施例四
图7为本申请实施例提供的一种电子设备的结构示意图。下面参考图7，其示出了适于用来实现本申请实施例的电子设备500的结构示意图。图7示出的电子设备500仅仅是一个示例，不应对本申请实施例的功能和使用范围带来任何限制。
如图7所示，电子设备500可以包括处理装置(例如中央处理器、图形处理器等)501，其可以根据存储在只读存储器(Read-Only Memory，ROM)502中的程序或者从存储装置508加载到随机访问存储器(Random Access Memory，RAM)503中的程序而执行多种适当的动作和处理。在RAM 503中，还存储有电子设备500操作所需的多种程序和数据。处理装置501、ROM 502以及RAM 503通过总线504彼此相连。输入/输出(Input/Output，I/O)接口505也连接至总线504。
通常，以下装置可以连接至I/O接口505：包括例如触摸屏、触摸板、键盘、鼠标、摄像头、麦克风、加速度计、陀螺仪等的输入装置506；包括例如液晶显示器(Liquid Crystal Display，LCD)、扬声器、振动器等的输出装置507；包括例如磁带、硬盘等的存储装置508；以及通信装置509。通信装置509可以允许电子设备500与其他设备进行无线或有线通信以交换数据。虽然图7示出了具有多种装置的电子设备500，并不要求实施或具备所有示出的装置。可以替代地实施或具备更多或更少的装置。
根据本申请的实施例，上文参考流程图描述的过程可以被实现为计算机软件程序。例如，本申请的实施例包括一种计算机程序产品，其包括承载在非暂态计算机可读介质上的计算机程序，该计算机程序包含用于执行流程图所示的方法的程序代码。在这样的实施例中，该计算机程序可以通过通信装置509从网络上被下载和安装，或者从存储装置508被安装，或者从ROM 502被安装。在该计算机程序被处理装置501执行时，执行本实施例的方法中限定的上述功能。
本申请实施例提供的电子设备与上述实施例提供的高压直流线路保护的方法属于同一构思，未在本实施例中详尽描述的技术细节可参见上述实施例，并 且本实施例与上述实施例具有相同的效果。
实施例五
本申请实施例提供了一种计算机存储介质，其上存储有计算机程序，该程序被处理器执行时实现上述实施例所提供的高压直流线路保护的方法。
本申请上述的计算机可读介质可以是计算机可读信号介质或者计算机可读存储介质或者是上述两者的任意组合。计算机可读存储介质例如可以是——电、磁、光、电磁、红外线、或半导体的系统、装置或器件，或者任意以上的组合。计算机可读存储介质的例子可以包括：具有一个或多个导线的电连接、便携式计算机磁盘、硬盘、RAM、ROM、可擦式可编程只读存储器(Erasable Programmable Read-Only Memory，EPROM或闪存)、光纤、便携式紧凑磁盘只读存储器(Compact Disc Read-Only Memory，CD-ROM)、光存储器件、磁存储器件、或者上述的任意合适的组合。在本申请中，计算机可读存储介质可以是任何包含或存储程序的有形介质，该程序可以被指令执行系统、装置或者器件使用或者与其结合使用。而在本申请中，计算机可读信号介质可以包括在基带中或者作为载波一部分传播的数据信号，其中承载了计算机可读的程序代码。这种传播的数据信号可以采用多种形式，包括电磁信号、光信号或上述的任意合适的组合。计算机可读信号介质还可以是计算机可读存储介质以外的任何计算机可读介质，该计算机可读信号介质可以发送、传播或者传输用于由指令执行系统、装置或者器件使用或者与其结合使用的程序。计算机可读介质上包含的程序代码可以用任何适当的介质传输，包括：电线、光缆、射频(Radio Frequency，RF)等等，或者上述的任意合适的组合。
在一些实施方式中，客户端、服务器可以利用诸如超文本传输协议(HyperText Transfer Protocol，HTTP)之类的任何当前已知或未来研发的网络协议进行通信，并且可以与任意形式或介质的数字数据通信(例如，通信网络)互连。通信网络的示例包括局域网(Local Area Network，LAN)，广域网(Wide Area Network，WAN)，网际网(例如，互联网)以及端对端网络(例如，ad hoc端对端网络)，以及任何当前已知或未来研发的网络。
上述计算机可读介质可以是上述电子设备中所包含的；也可以是单独存在，而未装配入该电子设备中。
可以以一种或多种程序设计语言或其组合来编写用于执行本申请的操作的计算机程序代码，上述程序设计语言包括面向对象的程序设计语言—诸如Java、Smalltalk、C++，还包括常规的过程式程序设计语言—诸如“C”语言或类似的程序设计语言。程序代码可以完全地在用户计算机上执行、部分地在用户计算机上执行、作为一个独立的软件包执行、部分在用户计算机上部分在远程计算机 上执行、或者完全在远程计算机或服务器上执行。在涉及远程计算机的情形中，远程计算机可以通过任意种类的网络——包括LAN或WAN—连接到用户计算机，或者，可以连接到外部计算机(例如利用因特网服务提供商来通过因特网连接)。
附图中的流程图和框图，图示了按照本申请多种实施例的系统、方法和计算机程序产品的可能实现的体系架构、功能和操作。在这点上，流程图或框图中的每个方框可以代表一个模块、程序段、或代码的一部分，该模块、程序段、或代码的一部分包含一个或多个用于实现规定的逻辑功能的可执行指令。也应当注意，在有些作为替换的实现中，方框中所标注的功能也可以以不同于附图中所标注的顺序发生。例如，两个接连地表示的方框实际上可以基本并行地执行，它们有时也可以按相反的顺序执行，这依所涉及的功能而定。也要注意的是，框图和/或流程图中的每个方框、以及框图和/或流程图中的方框的组合，可以用执行规定的功能或操作的专用的基于硬件的系统来实现，或者可以用专用硬件与计算机指令的组合来实现。
本文中以上描述的功能可以至少部分地由一个或多个硬件逻辑部件来执行。例如，非限制性地，可以使用的示范类型的硬件逻辑部件包括：现场可编程门阵列(Field Programmable Gate Array，FPGA)、专用集成电路(Application Specific Integrated Circuit，ASIC)、专用标准产品(Application Specific Standard Parts，ASSP)、片上系统(System on Chip，SOC)、复杂可编程逻辑设备(Complex Programming Logic Device，CPLD)等等。
在本申请的上下文中，机器可读介质可以是有形的介质，其可以包含或存储以供指令执行系统、装置或设备使用或与指令执行系统、装置或设备结合地使用的程序。机器可读介质可以是机器可读信号介质或机器可读储存介质。机器可读介质可以包括电子的、磁性的、光学的、电磁的、红外的、或半导体系统、装置或设备，或者上述内容的任何合适组合。机器可读存储介质的示例会包括基于一个或多个线的电气连接、便携式计算机盘、硬盘、RAM、ROM、EPROM或快闪存储器、光纤、CD-ROM、光学储存设备、磁储存设备、或上述内容的任何合适组合。

Claims (13)

  1. 一种高压直流线路保护的方法，包括：
    获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数；
    基于所述直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和所述线模故障电流的连续变化率；
    根据所述线模故障电流和所述线模故障电流的连续变化率判断是否启动线路保护；
    响应于启动所述线路保护，基于所述直流线路参数、所述直流系统运行参数和所述线模故障电压的首峰值对所述线模故障电压进行补偿；
    根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于所述高压直流线路发生故障，基于所述零模故障电压判断线路故障极性。
  2. 根据权利要求1所述的方法，其中，所述直流线路参数包括：直流线路总长度L，直流线路单位长度的电感L0、直流线路单位长度的电容C0、直流线路单位长度的电阻R0、直流线路单位长度的电导G0、直流线路线模波阻抗Zc1、直流线路零模波阻抗Zc0、直流线路单位长度的线模衰减系数ka1和线模色散时间常数τa1；
    所述直流系统运行参数包括：直流系统整流侧正常运行时直流电压Ur、和直流系统逆变侧正常运行时直流电压Ui；
    所述直流线路保护安装处运行参数包括：正极直流电压up(k)、负极直流电压un(k)、正极直流电流ip(k)和负极直流电流in(k)，其中，采样周期Ts，k表示离散采样点序列。
  3. 根据权利要求2所述的方法，其中，所述基于所述直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和所述线模故障电流的连续变化率，包括：
    基于所述直流线路保护安装处运行参数计算采样点k的正极线路故障电流分量Δip(k)＝ip(k)-ip(k-n0)，负极线路故障电流分量Δin(k)＝in(k)-in(k-n0)，正极线路故障电压分量Δup(k)＝up(k)-up(k-n0)，负极线路故障电压分量Δun(k)＝un(k)-un(k-n0)；其中，ip(k-n0)为所述采样点k前的n0个采样点的正极电流分量，up(k-n0)为所述采样点k前的n0个采样点的正极电压分量，in(k-n0)为所述采样点k前的n0个采样点的负极电流分量，un(k-n0)为所述采样点k前的n0个采样点的负极电压分量；
    对所述正极线路故障电流分量和所述负极线路故障电流分量进行相模变换得到所述采样点k的线模故障电流Δi1(k)：
    对所述正极线路故障电压分量和所述负极线路故障电压分量进行相模变换得到所述采样点k的零模故障电压Δu0(k)和线模故障电压Δu1(k)：
    计算所述采样点k的线模故障电流Δi1(k)在所述采样点k后连续3个采样点的变化率：
  4. 根据权利要求3所述的方法，其中，所述根据所述线模故障电流和所述线模故障电流的连续变化率判断是否启动线路保护，包括：
    用线模故障电流越限启动与线模故障电流的连续变化率启动双重判据作为线路保护启动判据：
    判据1，Δi1(k)＞Δi1set；其中，Δi1set为线模故障电流越限启动阈值；
    判据2，
    在所述判据1与所述判据2均被满足的情况下，启动所述线路保护，并记录启动线路保护时对应的采样点为ks，故障时刻ts为ksTs。
  5. 根据权利要求4所述的方法，还包括：
    在所述判据1与所述判据2中的至少之一未被满足的情况下，确定所述高压直流线路未发生故障，返回执行所述获取直流线路参数和直流系统运行参数，采样直流线路保护安装处运行参数的操作。
  6. 根据权利要求4或5所述的方法，其中，所述线模故障电流越限启动阈值Δi1set为0.01pu。
  7. 根据权利要求4或5所述的方法，其中，所述基于所述直流线路参数、所述直流系统运行参数和所述线模故障电压的首峰值对所述线模故障电压进行补偿，包括：
    计算直流系统正常运行的情况下高压直流线路中点位置xmid处的直流电压Ufmid：

    计算所述直流线路中点位置xmid处发生接地电阻Rf的接地故障时保护安装 处的线模故障电压分量u1mid：
    Rf＝0Ω
    计算线路保护动作后线模故障电压分量u1mid在60个采样点中的最大值u1midmax，并将线模故障电压分量u1midmax作为补偿参考值；
    在所述高压直流线路一位置x km处发生故障的情况下，计算线路保护动作后线模故障电压Δu1(k)在60个采样点中的最大值u1max，其中，记录u1max对应的采样点为kmax，u1max对应到达时刻tu1max为kmaxTs，u1max表示为：
    u1max＝max([Δu1(ks)，Δu1(ks+60)])；
    在所述高压直流线路一位置x km处发生故障的情况下，计算线模故障电压的补偿系数kcomp为：
    在采样点区间[ks,ks+kmax]中，将每个采样点对应的线模故障电压乘以补偿系数kcomp，得到补偿后的线模故障电压u1comp[kmax-ks+1]：
    u1comp[kmax-ks+1]＝kcomp·(Δu1(ks),Δu1(ks+1),···,Δu1(ks+kmax))。
  8. 根据权利要求6所述的方法，其中，所述根据补偿后的线模故障电压判断高压直流线路是否发生故障，包括：
    以补偿后的线模故障电压u1comp(k)构造直流线路内外故障的判据：
    判据a，|u1comp(ks+1)|-|u1comp(ks)|＞Δset1；其中，Δset1是直流线路故障区内整定值；
    判据b，|u1comp(ks+2)|-|u1comp(ks)|＞Δset2；其中，Δset2是直流线路故障区内整定值；
    判据c，kcomp＜krel·kset；其中，krel为可靠系数，kset为直流线路末端发生接地电阻Rf＝500Ω接地故障时的补偿系数，Rf为500Ω；
    在所述判据a、所述判据b和所述判据c均被满足的情况下，判定所述高压直流线路发生故障；
    在所述判据a、所述判据b和所述判据c中的至少之一未被满足的情况下，判定所述高压直流线路未发生故障。
  9. 根据权利要求8所述的方法，其中，Δset1为0.08125pu，Δset2为0.125pu。
  10. 根据权利要求8所述的方法，其中，所述基于所述零模故障电压判断线路故障极性，包括：
    以零模故障电压Δu0(ks)构造故障极性判据：
    在Δu0(ks)＞u0set的情况下，判定所述线路故障极性为正极故障；
    在Δu0(ks)＜-u0set的情况下，判定所述线路故障极性为负极故障；
    在-u0set＜Δu0(ks)＜u0set的情况下，判定所述线路故障极性为双极故障；
    其中，u0set为故障极性判定阈值，按照高压直流线路发生双极故障时的最大不平衡电压进行整定。
  11. 一种高压直流线路保护的系统，包括：采集模块、计算模块、第一判定模块、补偿模块和第二判定模块；
    所述采集模块设置为获取直流线路参数和直流系统运行参数，并采样直流线路保护安装处运行参数；
    所述计算模块设置为基于所述直流线路保护安装处运行参数计算采样点的线模故障电压、零模故障电压、线模故障电流和所述线模故障电流的连续变化率；
    所述第一判定模块设置为根据所述线模故障电流和所述线模故障电流的连续变化率判断是否启动线路保护；
    所述补偿模块设置为响应于启动所述线路保护，基于所述直流线路参数、所述直流系统运行参数和所述线模故障电压的首峰值对所述线模故障电压进行补偿；
    所述第二判定模块设置为根据补偿后的线模故障电压判断高压直流线路是否发生故障；响应于所述高压直流线路发生故障，基于所述零模故障电压判断线路故障的极性。
  12. 一种电子设备，包括：
    至少一个处理器；
    存储装置，设置为存储至少一个程序；
    当所述至少一个程序被所述至少一个处理器执行，使得所述至少一个处理器实现如权利要求1-10中任一项所述的高压直流线路保护的方法。
  13. 一种计算机可读存储介质，存储有计算机程序，所述程序被处理器执行时实现如权利要求1-10中任一项所述的高压直流线路保护的方法。
PCT/CN2023/109542 2022-08-31 2023-07-27 高压直流线路保护的方法及系统 WO2024045962A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211052988.7 2022-08-31
CN202211052988.7A CN115425626A (zh) 2022-08-31 2022-08-31 基于故障电压行波补偿的混合直流线路保护方法及系统

Publications (1)

Publication Number Publication Date
WO2024045962A1 true WO2024045962A1 (zh) 2024-03-07

Family

ID=84200661

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/109542 WO2024045962A1 (zh) 2022-08-31 2023-07-27 高压直流线路保护的方法及系统

Country Status (2)

Country Link
CN (1) CN115425626A (zh)
WO (1) WO2024045962A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115425626A (zh) * 2022-08-31 2022-12-02 国网四川省电力公司电力科学研究院 基于故障电压行波补偿的混合直流线路保护方法及系统
CN116431961B (zh) * 2023-04-19 2023-12-19 南通大学 一种柔性直流电网直流线路波阻抗实时计算方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102279309A (zh) * 2011-03-29 2011-12-14 昆明理工大学 一种特高压直流线路保护启动判据的方法
WO2018233294A1 (zh) * 2017-06-19 2018-12-27 天津大学 一种高压直流输电线路故障类型判断方法
CN109119977A (zh) * 2018-09-20 2019-01-01 山东大学 基于单端电压的多端柔性直流电网直流线路快速保护方法及系统
CN111130074A (zh) * 2020-01-07 2020-05-08 西安交通大学 基于电压首极值时间的直流输电线超高速保护系统及方法
CN112363013A (zh) * 2020-10-30 2021-02-12 西安理工大学 一种混合直流输电系统直流线路区内外故障判别方法
CN115425626A (zh) * 2022-08-31 2022-12-02 国网四川省电力公司电力科学研究院 基于故障电压行波补偿的混合直流线路保护方法及系统

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102279309A (zh) * 2011-03-29 2011-12-14 昆明理工大学 一种特高压直流线路保护启动判据的方法
WO2018233294A1 (zh) * 2017-06-19 2018-12-27 天津大学 一种高压直流输电线路故障类型判断方法
CN109119977A (zh) * 2018-09-20 2019-01-01 山东大学 基于单端电压的多端柔性直流电网直流线路快速保护方法及系统
CN111130074A (zh) * 2020-01-07 2020-05-08 西安交通大学 基于电压首极值时间的直流输电线超高速保护系统及方法
CN112363013A (zh) * 2020-10-30 2021-02-12 西安理工大学 一种混合直流输电系统直流线路区内外故障判别方法
CN115425626A (zh) * 2022-08-31 2022-12-02 国网四川省电力公司电力科学研究院 基于故障电压行波补偿的混合直流线路保护方法及系统

Also Published As

Publication number Publication date
CN115425626A (zh) 2022-12-02

Similar Documents

Publication Publication Date Title
WO2024045962A1 (zh) 高压直流线路保护的方法及系统
WO2019080238A1 (zh) 柔性直流输电线路的电压行波差动保护时域计算方法
CN105223466B (zh) 一种利用模极大值比的特高压直流输电线路单端测距方法
CN113687258A (zh) 一种直流电源供电系统及其直流电弧检测方法和装置
CN105305917A (zh) 相电流采样值失效处理方法和三相交流电机控制器
CN108649597B (zh) 一种故障迁移方法和故障对hvdc换相失败影响的分析方法
CN113033077A (zh) 一种基于神经网络算法的直流输电线路故障测距方法
CN114019242A (zh) 光伏逆变器直流侧绝缘阻抗检测方法及装置
CN104092201B (zh) 远距离特高压交流输电线路故障判别方法
CN110794210B (zh) 电压谐波隔离效果的判断方法、装置、供电系统、计算机设备及存储介质
CN112083280A (zh) 一种识别混合多端直流输电系统故障区间的方法
CN104111402A (zh) 一种电力电联交叉互联系统的接线检测方法和装置
CN115598563A (zh) 一种基于粗糙神经网络的配电网单相接地故障诊断方法
CN115469182A (zh) 基于高频波形特性的直流微电网高阻故障检测方法及装置
CN207442691U (zh) 一种电动汽车单相双向dc/ac变换器自适应控制装置
CN113030648B (zh) 电力电缆故障点位置确定方法、装置及终端设备
CN108020793A (zh) 特种电源输出脉冲检测电路及特种电源失电检测方法
Domínguez et al. New quick-convergence invariant digital filter for phasor estimation
CN2932398Y (zh) 多通道谐波监测与分析装置
CN109670254B (zh) 机电暂态与电磁暂态混合仿真的接口位置选择方法及系统
US9620980B2 (en) Charging system, charging control device and charging method
CN115951264B (zh) 线路接地故障检测方法、装置、设备与介质
CN101968523A (zh) 直流系统环路及绝缘故障诊断方法
Chu et al. Pilot protection for hybrid multi-terminal HVDC transmission lines based on Euclidean distance between differential current and distributed capacitance current
CN114384373A (zh) 基于可控变流器的主动探测式电缆故障定位方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23858997

Country of ref document: EP

Kind code of ref document: A1