Method, device and equipment for analyzing breaking risk of high-voltage circuit breaker and medium

Abstract

The invention discloses a high-voltage circuit breaker breaking risk analysis method, device and equipment and a medium, which are used for evaluating the breaking failure risk of a high-voltage circuit breaker and reducing the breaking failure probability of the high-voltage circuit breaker. The method comprises the following steps: acquiring a zero crossing point current change rate of the high-voltage circuit breaker under the action of a current harmonic component when a near-field fault occurs; calculating the total recovery voltage rise time of the high-voltage circuit breaker according to the zero crossing point current change rate; according to the total recovery voltage rise time, calculating a first peak voltage reached by the transient recovery voltage at the two ends of the high-voltage circuit breaker before the oscillation voltage at the line side disappears; calculating an initial recovery voltage rise rate of the high-voltage circuit breaker by adopting the total recovery voltage rise time and the first peak voltage; and judging whether the initial recovery voltage rise rate is greater than a preset threshold, and if yes, judging that the high-voltage circuit breaker has a breaking failure risk.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage circuit breakers, and in particular to a method, device, equipment and medium for analyzing the risk of breaking a high-voltage circuit breaker. Background Art

[0002] In the power system, high-voltage circuit breakers are responsible for closing, carrying and interrupting the normal current of the operating circuit and closing, carrying and interrupting the specified overload current within the specified time. When interrupting the short-circuit current, an arc will be generated at the break. After the arc is extinguished, a transient recovery voltage (TRV) of up to hundreds of kilovolts will be immediately generated between the breaks, affecting the successful opening of the circuit breaker. Summary of the invention

[0003] The present invention provides a method, device, equipment and medium for analyzing the breaking risk of a high-voltage circuit breaker, which are used to evaluate the breaking failure risk of a high-voltage circuit breaker and reduce the breaking failure probability of the high-voltage circuit breaker.

[0004] The present invention provides a high-voltage circuit breaker disconnection risk analysis method, which is applied to a power system; the method comprises:

[0005] Obtaining the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component;

[0006] Calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate;

[0007] Calculate, according to the overall recovery voltage rise time, a first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears;

[0008] Calculating an initial recovery voltage rise rate of the high-voltage circuit breaker using the overall recovery voltage rise time and the first peak voltage;

[0009] It is determined whether the initial recovery voltage rise rate is greater than a preset threshold value. If so, it is determined that the high-voltage circuit breaker has a risk of breaking failure.

[0010] Optionally, the step of calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate comprises:

[0011] Calculating a first peak-to-peak voltage of the oscillating voltage on the line side of the high-voltage circuit breaker;

[0012] Obtaining the line wave impedance of the power system;

[0013] Calculate the rise time to reach the first peak-to-peak voltage according to the zero-crossing current change rate, the first peak-to-peak voltage and the line impedance;

[0014] Obtaining a line-side time delay of the high-voltage circuit breaker;

[0015] The overall recovery voltage rise time of the high-voltage circuit breaker is calculated using the line-side time delay and the rise time.

[0016] Optionally, the step of calculating a first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker comprises:

[0017] Obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of the circuit breaker;

[0018] The first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker is calculated using the near-field fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker.

[0019] Optionally, the step of calculating, according to the overall recovery voltage rise time, a first peak voltage reached by the transient recovery voltage across the high-voltage circuit breaker before the line-side oscillation voltage disappears, comprises:

[0020] Obtaining a power supply side delay of the high voltage circuit breaker;

[0021] Obtaining the bus voltage of the power system when the high-voltage circuit breaker interrupts the nearby fault;

[0022] Obtaining the recovery voltage rising rate on the power supply side of the high-voltage circuit breaker when breaking the near-zone fault;

[0023] The first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears is calculated based on the bus voltage, the recovery voltage rise rate, the overall recovery voltage rise time, the power supply side delay and the first peak-to-peak voltage.

[0024] Optionally, the step of calculating the initial recovery voltage rise rate of the high-voltage circuit breaker by using the overall recovery voltage rise time and the first peak voltage comprises:

[0025] The difference between the first peak voltage and the overall recovery voltage rise time is calculated to obtain an initial recovery voltage rise rate of the high-voltage circuit breaker.

[0026] The present invention also provides a high-voltage circuit breaker disconnection risk analysis device, which is applied to a power system; the device comprises:

[0027] A zero-crossing current change rate acquisition module is used to obtain the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component;

[0028] An overall recovery voltage rise time calculation module, used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate;

[0029] A first peak voltage calculation module, used for calculating, according to the overall recovery voltage rise time, a first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears;

[0030] An initial recovery voltage rise rate calculation module, configured to calculate an initial recovery voltage rise rate of the high-voltage circuit breaker by using the overall recovery voltage rise time and the first peak voltage;

[0031] The judgment module is used to judge whether the initial recovery voltage rise rate is greater than a preset threshold value. If so, it is determined that the high-voltage circuit breaker has a risk of breaking failure.

[0032] Optionally, the overall recovery voltage rise time calculation module includes:

[0033] A first peak-to-peak voltage calculation submodule, used for calculating a first peak-to-peak voltage of the oscillating voltage on the line side of the high-voltage circuit breaker;

[0034] A line wave impedance acquisition submodule, used to acquire the line wave impedance of the power system;

[0035] A rise time calculation submodule, used for calculating the rise time to reach the first peak-to-peak voltage according to the zero-crossing current change rate, the first peak-to-peak voltage and the line wave impedance;

[0036] A line-side delay acquisition submodule, used to acquire the line-side delay of the high-voltage circuit breaker;

[0037] The overall recovery voltage rise time calculation submodule is used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker using the line-side delay and the rise time.

[0038] Optionally, the first peak-to-peak voltage calculation submodule includes:

[0039] A unit for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of a circuit breaker, for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of the circuit breaker;

[0040] The first peak-to-peak voltage calculation unit is used to calculate a first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker by using the near-field fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker.

[0041] The present invention also provides an electronic device, the device comprising a processor and a memory:

[0042] The memory is used to store program code and transmit the program code to the processor;

[0043] The processor is used to execute the high-voltage circuit breaker disconnection risk analysis method as described in any one of the above items according to the instructions in the program code.

[0044] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program codes, and the program codes are used to execute the high-voltage circuit breaker disconnection risk analysis method as described in any one of the above items.

[0045] It can be seen from the above technical scheme that the present invention has the following advantages: the present invention discloses a method for analyzing the risk of high-voltage circuit breaker disconnection, and specifically discloses: obtaining the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component; calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate; calculating the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears according to the overall recovery voltage rise time; using the overall recovery voltage rise time and the first peak voltage to calculate the initial recovery voltage rise rate of the high-voltage circuit breaker; judging whether the initial recovery voltage rise rate is greater than a preset threshold, if so, judging that the high-voltage circuit breaker has a risk of disconnection failure. The present invention obtains the zero-crossing current change rate of the near-zone fault of the high-voltage circuit breaker under different harmonic components to calculate the initial recovery voltage rise rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of different harmonic components, so as to judge whether the high-voltage circuit breaker has a risk of disconnection failure when a near-zone fault actually occurs in the power system, thereby adjusting the harmonic components and other parameters of the power system to avoid the risk when a near-zone fault occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0047] Figure 1 A flowchart of the steps of a high-voltage circuit breaker disconnection risk analysis method provided by an embodiment of the present invention;

[0048] Figure 2 A simplified single-phase circuit with ITRV (initial transient recovery voltage) on the power supply side and a time-delayed near-field fault on the line side;

[0049] Figure 3 It is a schematic diagram of the curve of the initial recovery voltage rise rate changing with the harmonic content;

[0050] Figure 4 It is a schematic diagram of the curve of initial rise time changing with harmonic content;

[0051] Figure 5 It is the circuit and arc simulation model of the circuit breaker near-zone breaking process;

[0052] Figure 6 It is a schematic diagram of the short-circuit current curve of the nearby fault under the superposition of different harmonic contents;

[0053] Figure 7 It is a schematic diagram of the recovery voltage waveform under the superposition of different harmonic contents;

[0054] Figure 8 A structural block diagram of a high-voltage circuit breaker disconnection risk analysis device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The embodiments of the present invention provide a method, device, equipment and medium for analyzing the breaking risk of a high-voltage circuit breaker, which are used to evaluate the breaking failure risk of a high-voltage circuit breaker and reduce the breaking failure probability of the high-voltage circuit breaker.

[0056] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] See also Figure 1 , Figure 1 A flowchart of the steps of a high-voltage circuit breaker disconnection risk analysis method provided by an embodiment of the present invention.

[0058] A high-voltage circuit breaker disconnection risk analysis method provided by the present invention is applied to a power system and may specifically include the following steps:

[0059] Step 101, obtaining the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component;

[0060] Step 102, calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate;

[0061] When a near-field fault occurs, the superposition of different harmonic components will result in different near-field fault zero-crossing current change rates. In an embodiment of the present invention, the zero-crossing current change rate when a near-field fault occurs can be obtained based on the harmonic components and short-circuit current of the current power system. The overall recovery voltage rise time of the high-voltage circuit breaker can be calculated by the zero-crossing current change rate.

[0062] In one example, step 102 may include the following sub-steps:

[0063] S21, obtaining the nearby fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker;

[0064] S22, calculating the first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker using the near-fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker;

[0065] S23, obtaining the line wave impedance of the power system;

[0066] S24, calculating the rise time to reach the first wave peak-to-peak voltage according to the zero-crossing current change rate, the first wave peak-to-peak voltage and the line wave impedance;

[0067] S25, obtaining the line side delay of the high voltage circuit breaker;

[0068] S26, calculating the overall recovery voltage rise time of the high voltage circuit breaker using the line side delay and rise time.

[0069] In a specific implementation, under a local fault condition, the circuit breaker transient recovery voltage is a combination of the power supply side and the line side.

[0070] The calculation condition is a local fault: single-phase grounding in a neutral point grounding system, and the first-pole coefficient is equal to 1. The corresponding power supply side has ITRV (initial transient recovery voltage), and the line side has a time-delay local fault delay to simplify the single-phase circuit as follows Figure 2 As shown. Assume that the rated voltage of the circuit breaker is 550kV, and the rated short-circuit current is 50kA and 63kA. The local fault condition is L90, there is a 0.5μs delay on the line side, a 2μs delay on the power supply side and ITRV (initial transient recovery voltage), and the transient characteristics of the recovery voltage under the action of harmonics are calculated and analyzed. The simplified single-phase circuit is as follows Figure 1 When the fault point is grounded, the current will flow through the reactance X S , X L , X B The series circuit is composed of G is the power supply voltage relative to ground, X S , X B , X L are the power frequency reactance values ​​of the power supply side, busbar side, and line side, respectively.S , Z L , Z i They are TRV control element and ITRV control element on the power supply side and line side respectively, C d , C dL is the power supply side and line side delay capacitance, C B is the circuit breaker, Z is the line wave impedance, and L is the line length to the fault point.

[0071] When a local fault occurs, the first peak voltage u of the line side oscillation voltage L* It can be calculated by the following formula:

[0072]

[0073] in, is the peak factor, is the rated voltage of the circuit breaker, To interrupt the current for nearby faults, is the rated short-circuit breaking current.

[0074] The rise time of the first peak-to-peak voltage reaching the line side voltage Line wave impedance and zero-crossing current change rate With the superposition of harmonic components in the nearby fault current, the current rise rate at the zero-crossing moment increases significantly, thereby reducing the rise time of the line side to reach the first peak voltage and the overall recovery voltage rise time. :

[0075]

[0076]

[0077] in, is the line side delay, which is 0.5μs. GB / T 1984-2014 stipulates that when the rated voltage is higher than 252kV, the line wave impedance is 450Ω and the peak factor k is 1.6.

[0078] Step 103, calculating the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears according to the overall recovery voltage rise time;

[0079] In an embodiment of the present invention, the first voltage peak value reached by the transient recovery voltage at both ends of the circuit breaker before the line-side oscillation voltage disappears is mainly determined by the line side; after obtaining the overall recovery voltage rise time of the line side, the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears can be calculated based on the overall recovery voltage rise time.

[0080] In one example, step 103 may include the following sub-steps:

[0081] S31, obtaining the power supply side delay of the high voltage circuit breaker;

[0082] S32, obtaining the bus voltage of the power system when the high-voltage circuit breaker interrupts the nearby fault;

[0083] S33, obtaining the recovery voltage rising rate on the power supply side of the high-voltage circuit breaker when the nearby fault is interrupted;

[0084] S34, calculating the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears based on the bus voltage, the recovery voltage rise rate, the overall recovery voltage rise time, the power supply side delay and the first peak voltage.

[0085] In the specific implementation, when the nearby fault is interrupted, the recovery voltage rise rate on the power supply side of the circuit breaker is The initial transient recovery voltage (ITRV) lasts for 1.0 μs, and the bus voltage drop under the ITRV is:

[0086]

[0087] in, The multiplier is equal to 0.116kV / kA, The peak factor is 1.4.

[0088] The first voltage peak value reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears is mainly determined by the line side. The first peak voltage expression is:

[0089]

[0090] in, The delay on the power supply side is 2μs.

[0091] Step 104, calculating the initial recovery voltage rise rate of the high-voltage circuit breaker using the overall recovery voltage rise time and the first peak voltage;

[0092] After obtaining the overall recovery voltage rise time and the first peak voltage, the initial recovery voltage rise rate of the high-voltage circuit breaker can be derived. The specific steps are:

[0093] The difference between the first peak voltage and the overall recovery voltage rise time is calculated to obtain the initial recovery voltage rise rate of the high voltage circuit breaker.

[0094] The formula is:

[0095]

[0096] Step 105, determining whether the initial recovery voltage rise rate is greater than a preset threshold value, and if so, determining that the high-voltage circuit breaker has a risk of breaking failure.

[0097] In the embodiment of the present invention, after calculating the initial recovery voltage rise rate of the high-voltage circuit breaker when a local fault occurs under the action of different harmonic components, it can be determined whether there is a risk of circuit breaker breaking failure.

[0098] In actual scenarios, the higher the initial recovery voltage rise rate, the greater the risk. Therefore, a preset threshold can be used to determine whether the high-voltage circuit breaker has a greater risk of breaking failure when a nearby fault occurs under the current power system parameters. If it is determined that a greater risk of breaking failure may occur when a nearby fault occurs in the current power system, the power system parameters (such as harmonic content) can be adjusted.

[0099] As shown in Table 1, for the two working conditions of L90 short-circuit current 45kA and 56.7kA, the calculation and analysis of RRRV (initial recovery voltage rise rate) and initial rise time are carried out by superimposing the 3rd, 5th, and 7th harmonics. Table 1 lists the parameter calculation results under some working conditions. It can be found that with the increase of rated short-circuit current, harmonic content, and harmonic frequency, the current change rate at zero crossing time increases significantly, thereby increasing the voltage rise speed on the line side. Under the condition that the first peak value on the line side is constant, the time t to reach the first peak voltage T The voltage rise on the power supply side is relatively reduced, and the first peak value u of the recovery voltage at both ends of the circuit breaker is T The corresponding decrease, but the final recovery voltage rise rate RRRV shows a significant upward trend, and the difficulty of high-voltage circuit breaker opening increases. At the same time, the increase in current level will also increase the power supply side ITRV, further increasing the recovery voltage rise rate.

[0100] Table 1

[0101]

[0102] Figure 3 It is a schematic diagram of the curve of the initial recovery voltage rise rate changing with the harmonic content. Figure 4 This is a schematic diagram of the initial rise time versus harmonic content curve. Figure 3 and Figure 4 It can be obtained that RRRV is approximately proportional to the harmonic content, and the rise time is approximately inversely proportional to the harmonic content. The higher the rated short-circuit current, the larger the RRRV starting value, and the greater the slope of its increase with the harmonic content. This is mainly caused by the large current change rate at the zero-crossing moment. Under the same condition of the superposition content of harmonic current, the higher the harmonic frequency, the greater the increase in the current change rate, which leads to an increase in RRRV, t TThe increase of RRRV and the decrease of tT both increase the difficulty of post-arc medium recovery, which is not conducive to the successful opening of the circuit breaker.

[0103] The present invention obtains the rate of change of the zero-crossing current of the near-field fault of the high-voltage circuit breaker under different harmonic components to calculate the initial recovery voltage rise rate of the high-voltage circuit breaker when a near-field fault occurs under the action of different harmonic components, so as to judge whether there is a risk of breaking failure of the high-voltage circuit breaker when a near-field fault actually occurs in the power system, thereby adjusting the parameters such as the harmonic components of the power system to avoid the risk when a near-field fault occurs.

[0104] Furthermore, in the embodiment of the present invention, in order to further study the influence of harmonic content on the late rise process of the circuit breaker near-zone fault recovery voltage, according to the simplified circuit of the circuit breaker near-zone fault test, a circuit and arc simulation model of the circuit breaker near-zone breaking process was built in the MATLAB / Simulink module, such as Figure 5 As shown. h It is a harmonic current source, which is used to introduce harmonic content into the short-circuit current. At the same time, corresponding resistance is added to the power frequency reactance on the power supply side and the line side to simulate the line resistance in the actual test. B Small, not considered in modeling.

[0105] The Mayr arc model in the simulation model is used to describe the arc behavior during the circuit breaker breaking process. It is built through a differential equation editor, step signal, constant value detection, and controlled current source. Its principle equation is:

[0106]

[0107] Where g is the arc conductance, is the arc voltage, is the arc current, is the arc time constant, and P is the arc heat dissipation power. The Mayr arc model obtains the arc characteristic curve by studying the relationship between arc current and arc voltage. It is suitable for arc processes in the low current and zero zone stages, so it is used to calculate the post-arc recovery voltage rise process.

[0108] The influence of harmonics on transient characteristics within a few microseconds before the voltage is restored is obtained through the initial RRRV calculation. In order to further study the influence of harmonic content on the transient characteristics of the voltage restored by the nearby fault, a simulation study with a rated short-circuit current of 50kA and superimposed 5th harmonic currents of different contents was carried out in the MATLAB / Simulink module to quantitatively analyze the influence of harmonic content on the peak value and rise time of the post-arc recovery voltage.

[0109] The injection of 5th harmonic current with different contents is mainly achieved by setting the current peak value and current frequency in the harmonic current source Ih. Figure 6 shown. Figure 7 The recovery voltage waveforms under the superposition of different harmonic contents are given. It can be seen that the evolution law of the recovery voltage waveform under the action of harmonics is basically the same. The recovery voltage rise rate begins to increase with the increase of harmonic content around 50μs. The recovery voltage under the action of harmonics begins to be higher than the fundamental recovery voltage. Finally, the recovery voltage under the action of harmonics reaches its peak ahead of time, and the peak value is significantly higher than the fundamental recovery voltage.

[0110] See also Figure 8 , Figure 8 A structural block diagram of a high-voltage circuit breaker disconnection risk analysis device provided in an embodiment of the present invention.

[0111] An embodiment of the present invention provides a high-voltage circuit breaker disconnection risk analysis device, which is applied to a power system; the device includes:

[0112] The zero-crossing current change rate acquisition module 801 is used to obtain the zero-crossing current change rate of the high-voltage circuit breaker when a nearby fault occurs under the action of the current harmonic component;

[0113] The overall recovery voltage rise time calculation module 802 is used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate;

[0114] A first peak voltage calculation module 803, used to calculate the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears according to the overall recovery voltage rise time;

[0115] An initial recovery voltage rise rate calculation module 804 is used to calculate the initial recovery voltage rise rate of the high-voltage circuit breaker by using the overall recovery voltage rise time and the first peak voltage;

[0116] The judgment module 805 is used to judge whether the initial recovery voltage rising rate is greater than a preset threshold value. If so, it is determined that there is a risk of breaking failure of the high-voltage circuit breaker.

[0117] In the embodiment of the present invention, the overall recovery voltage rise time calculation module 802 includes:

[0118] A first peak-to-peak voltage calculation submodule is used to calculate a first peak-to-peak voltage of an oscillating voltage on a line side of a high-voltage circuit breaker;

[0119] A line wave impedance acquisition submodule is used to acquire the line wave impedance of the power system;

[0120] A rise time calculation submodule, used to calculate the rise time to reach the first wave peak-to-peak voltage according to the zero-crossing current change rate, the first wave peak-to-peak voltage and the line wave impedance;

[0121] A line-side delay acquisition submodule, used to acquire the line-side delay of the high-voltage circuit breaker;

[0122] The overall recovery voltage rise time calculation submodule is used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker using the line side delay and rise time.

[0123] In an embodiment of the present invention, the first peak-to-peak voltage calculation submodule includes:

[0124] A unit for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of a circuit breaker, for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of a circuit breaker;

[0125] The first wave crest-to-peak voltage calculation unit is used to calculate the first wave crest-to-peak voltage of the oscillating voltage on the line side of the high-voltage circuit breaker by using the near-field fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker.

[0126] In the embodiment of the present invention, the first peak voltage calculation module 803 includes:

[0127] A power supply side delay acquisition submodule, used to acquire the power supply side delay of the high voltage circuit breaker;

[0128] The bus voltage acquisition submodule is used to obtain the bus voltage of the power system when the high-voltage circuit breaker interrupts the nearby fault;

[0129] The recovery voltage rise rate acquisition submodule is used to obtain the recovery voltage rise rate on the power supply side of the high-voltage circuit breaker when the nearby fault is interrupted;

[0130] The first peak voltage calculation submodule is used to calculate the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears based on the bus voltage, the recovery voltage rise rate, the overall recovery voltage rise time, the power supply side delay and the first peak-to-peak voltage.

[0131] In an embodiment of the present invention, the initial recovery voltage rise rate calculation module includes:

[0132] The initial recovery voltage rise rate calculation submodule is used to calculate the difference between the first peak voltage and the overall recovery voltage rise time to obtain the initial recovery voltage rise rate of the high-voltage circuit breaker.

[0133] An embodiment of the present invention further provides an electronic device, the device comprising a processor and a memory:

[0134] The memory is used to store the program code and transmit the program code to the processor;

[0135] The processor is used to execute the high-voltage circuit breaker disconnection risk analysis method according to the instructions in the program code.

[0136] The embodiment of the present invention further provides a computer-readable storage medium, which is used to store program codes, and the program codes are used to execute the high-voltage circuit breaker disconnection risk analysis method of the embodiment of the present invention.

[0137] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0138] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0139] It will be appreciated by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0140] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0141] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0142] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0143] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0144] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0145] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing the risk of high-voltage circuit breaker disconnection, characterized in that: Applied to a power system; the method comprises: Obtaining the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component; Calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate; Calculate, according to the overall recovery voltage rise time, a first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears; Calculating an initial recovery voltage rise rate of the high-voltage circuit breaker using the overall recovery voltage rise time and the first peak voltage; It is determined whether the initial recovery voltage rise rate is greater than a preset threshold value. If so, it is determined that the high-voltage circuit breaker has a risk of breaking failure.

2. The method according to claim 1, characterized in that The step of calculating the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate comprises: Calculating a first peak-to-peak voltage of the oscillating voltage on the line side of the high-voltage circuit breaker; Obtaining the line wave impedance of the power system; Calculate the rise time to reach the first peak-to-peak voltage according to the zero-crossing current change rate, the first peak-to-peak voltage and the line impedance; Obtaining a line-side time delay of the high-voltage circuit breaker; The overall recovery voltage rise time of the circuit breaker is calculated using the line-side time delay and the rise time.

3. The method according to claim 2, characterized in that The step of calculating the first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker comprises: Obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of the circuit breaker; The first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker is calculated using the near-field fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker.

4. The method according to claim 1, characterized in that The step of calculating the first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears according to the overall recovery voltage rise time comprises: Obtaining a power supply side delay of the high voltage circuit breaker; Obtaining the bus voltage of the power system when the high-voltage circuit breaker interrupts the nearby fault; Obtaining the recovery voltage rising rate on the power supply side of the high-voltage circuit breaker when breaking the near-zone fault; The first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears is calculated based on the bus voltage, the recovery voltage rise rate, the overall recovery voltage rise time, the power supply side delay and the first peak-to-peak voltage.

5. The method according to claim 1, characterized in that The step of calculating the initial recovery voltage rise rate of the high-voltage circuit breaker by using the overall recovery voltage rise time and the first peak voltage comprises: The difference between the first peak voltage and the overall recovery voltage rise time is calculated to obtain an initial recovery voltage rise rate of the high-voltage circuit breaker.

6. A high-voltage circuit breaker disconnection risk analysis device, characterized in that: Applicable to power system; the device comprises: A zero-crossing current change rate acquisition module is used to obtain the zero-crossing current change rate of the high-voltage circuit breaker when a near-zone fault occurs under the action of the current harmonic component; An overall recovery voltage rise time calculation module, used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker according to the zero-crossing current change rate; A first peak voltage calculation module, used for calculating, according to the overall recovery voltage rise time, a first peak voltage reached by the transient recovery voltage at both ends of the high-voltage circuit breaker before the line-side oscillation voltage disappears; An initial recovery voltage rise rate calculation module, configured to calculate an initial recovery voltage rise rate of the high-voltage circuit breaker by using the overall recovery voltage rise time and the first peak voltage; The judgment module is used to judge whether the initial recovery voltage rise rate is greater than a preset threshold value. If so, it is determined that the high-voltage circuit breaker has a risk of breaking failure.

7. The device according to claim 6, characterized in that The overall recovery voltage rise time calculation module includes: A first peak-to-peak voltage calculation submodule, used for calculating a first peak-to-peak voltage of the oscillating voltage on the line side of the high-voltage circuit breaker; A line wave impedance acquisition submodule, used to acquire the line wave impedance of the power system; A rise time calculation submodule, used for calculating the rise time to reach the first peak-to-peak voltage according to the zero-crossing current change rate, the first peak-to-peak voltage and the line wave impedance; A line-side delay acquisition submodule, used to acquire the line-side delay of the high-voltage circuit breaker; The overall recovery voltage rise time calculation submodule is used to calculate the overall recovery voltage rise time of the high-voltage circuit breaker using the line-side delay and the rise time.

8. The device according to claim 7, characterized in that The first peak-to-peak voltage calculation submodule comprises: A unit for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of a circuit breaker, for obtaining a nearby fault breaking current, a rated short-circuit breaking current and a rated voltage of the circuit breaker; The first peak-to-peak voltage calculation unit is used to calculate a first peak-to-peak voltage of the line-side oscillation voltage of the high-voltage circuit breaker by using the near-field fault breaking current, the rated short-circuit breaking current and the rated voltage of the circuit breaker.

9. An electronic device, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the high-voltage circuit breaker disconnection risk analysis method according to any one of claims 1-5 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the high-voltage circuit breaker disconnection risk analysis method according to any one of claims 1-5.

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