Fault detection method, electronic equipment and computer readable storage medium

Abstract

The invention relates to the technical field of power system relay protection, in particular to a fault detection method, electronic equipment and a computer readable storage medium. The method comprises the following steps: collecting a plurality of first current vectors and a plurality of first voltage vectors at a first moment, and obtaining a plurality of second current vectors and a plurality of second voltage vectors of a second line protection device; determining a plurality of differential current amplitude break variables; if the value greater than the preset differential break variable threshold exists, acquiring a plurality of third current vectors and a plurality of third voltage vectors at a second moment, and acquiring a plurality of fourth current vectors and a plurality of fourth voltage vectors of a second line protection device; determining a first current break variable phase and a first voltage break variable phase; and if the first current break variable phase is not in the preset current break variable phase interval, and / or the first voltage break variable phase is not in the preset voltage break variable phase interval, determining that an internal fault occurs. The method can improve the sensitivity and accuracy of fault discrimination in a power system area.

Description

Technical Field

[0001] The present application relates to the technical field of relay protection for electric power systems, and in particular to a fault detection method, an electronic device, and a computer-readable storage medium. Background Art

[0002] In the power system, the line protection device can monitor the current at both ends of the line and determine whether the line is faulty based on the monitoring results. Once the line protection device detects a line fault, it will immediately operate to cut off the fault current, isolate the fault area from the normal area, prevent the fault from expanding, and protect other parts of the power system from being affected.

[0003] In traditional technical solutions, line protection devices usually determine whether a line fault occurs through the differential current and differential ratio coefficient at both ends of the line. However, with the rapid development of power systems, some electronic devices in the power system will affect the phase of the current under the influence of control strategies, thereby affecting the differential current and differential ratio coefficient at both ends of the line. As a result, even when a line fault occurs, the differential current at both ends of the line does not meet the differential current conditions when the line fault occurs, and the differential ratio coefficient at both ends of the line does not meet the differential ratio coefficient conditions when the line fault occurs. This reduces the sensitivity and accuracy of the line protection device in fault identification of the line. Summary of the invention

[0004] The embodiments of the present application provide a fault detection method, device, electronic device and computer-readable storage medium, which can accurately identify the fault in the transmission line when the fault occurs in the transmission line, thereby improving the sensitivity and accuracy of the fault identification in the transmission line.

[0005] In a first aspect, an embodiment of the present application provides a fault detection method, which is applied to a first line protection device, the first line protection device is used to monitor the circuit state of a multi-phase circuit, the first line protection device is in a connected state with a second line protection device, and the method includes: collecting a plurality of first current vectors and a plurality of first voltage vectors of the first line protection device at a first moment, and obtaining a plurality of second current vectors and a plurality of second voltage vectors of the second line protection device, the plurality of first current vectors, the plurality of first voltage vectors, the plurality of second current vectors, and the plurality of second voltage vectors all correspond one-to-one to the multi-phase circuit; determining a plurality of differential current amplitude mutation amounts according to the plurality of first current vectors and the plurality of second current vectors, the plurality of differential current amplitude mutation amounts corresponding one-to-one to the multi-phase circuit; if there is a first differential current amplitude mutation amount among the plurality of differential current amplitude mutation amounts, obtaining a plurality of third current vectors and a plurality of third voltage vectors of the first line protection device at the second moment, and obtaining a plurality of The second line protection device has multiple fourth current vectors and multiple fourth voltage vectors at the second moment, and the first differential current amplitude mutation is greater than the value of the preset differential mutation threshold; the multiple third current vectors, multiple third voltage vectors, multiple fourth current vectors and multiple fourth voltage vectors correspond to the multi-phase circuit one by one, the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period; the first current mutation phase is determined according to the multiple first current vectors, multiple second current vectors, multiple third current vectors and multiple fourth current vectors, and the first voltage mutation phase is determined according to the multiple first voltage vectors, multiple second voltage vectors, multiple third voltage vectors and multiple fourth voltage vectors; if the first current mutation phase is not in the preset current mutation phase interval, and / or the first voltage mutation phase is not in the preset voltage mutation phase interval, a first fault detection result is output, and the first fault detection result represents the fault in the occurrence area.

[0006] In some embodiments, the above method also includes: obtaining multiple second current mutation phases and multiple second voltage mutation phases within a first preset time period, the starting time of the first preset time period is the first time, and the first preset time period is less than a preset change period; if there is a second current mutation phase among the multiple second current mutation phases that is not in the preset current mutation phase interval, and / or there is a second voltage mutation phase among the multiple second voltage mutation phases that is not in the preset voltage mutation phase interval, then outputting a first fault detection result.

[0007] In some embodiments, if there is a second current mutation phase that is not in a preset current mutation phase interval among multiple second current mutation phases, and / or there is a second voltage mutation phase that is not in a preset voltage mutation phase interval among multiple second voltage mutation phases, a first fault detection result is output, including: if there is a second current mutation phase that is not in the preset current mutation phase interval among multiple second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among multiple second voltage mutation phases, then a corresponding plurality of differential current amplitudes are calculated according to multiple first current vectors and multiple second current vectors, and the plurality of differential current amplitudes correspond one-to-one to the multi-phase circuits; when there is a first differential current amplitude among the multiple differential current amplitudes, it is determined that an in-zone fault occurs in the first phase circuit corresponding to the first differential current amplitude, the first differential current amplitude is always greater than a preset differential current threshold within a second preset time period, the first phase circuit is a phase circuit in the multi-phase circuit, the starting time of the second preset time period is the first time, and the second preset time period is less than a preset change cycle.

[0008] In some embodiments, multiple differential current amplitude mutation amounts are determined based on multiple first current vectors and multiple second current vectors, including: calculating the first differential current amplitude of the second phase circuit based on the first current vector of the second phase circuit and the second current vector of the second phase circuit, and calculating the second differential current amplitude of the second phase circuit based on the third current vector of the second phase circuit and the fourth current vector of the second phase circuit, the second phase circuit being any one phase circuit of the multi-phase circuit; calculating the differential current amplitude mutation amount of the second phase circuit based on the first differential current amplitude and the second differential current amplitude, the differential current amplitude mutation amount being the absolute value of the difference between the first differential current amplitude and the second differential current amplitude.

[0009] In some embodiments, the phase of a first current mutation amount is determined based on multiple first current vectors, multiple second current vectors, multiple third current vectors, and multiple fourth current vectors, including: calculating the first positive-sequence current based on multiple first current vectors; calculating the second positive-sequence current based on multiple second current vectors; calculating the third positive-sequence current based on multiple third current vectors; calculating the fourth positive-sequence current based on multiple fourth current vectors; determining the vector difference between the first positive-sequence current and the third positive-sequence current as the first positive-sequence mutation current vector; determining the vector difference between the second positive-sequence current and the fourth positive-sequence current as the second positive-sequence mutation current vector; and calculating the phase of the first current mutation amount based on the first positive-sequence mutation current vector and the second positive-sequence mutation current vector.

[0010] In some embodiments, the first current mutation phase is a phase difference between a first current phase and a second current phase, the first current phase is a phase of a first positive sequence mutation current vector, and the second current phase is a phase of a second positive sequence mutation current vector.

[0011] In some embodiments, a first voltage mutation phase is determined based on multiple first voltage vectors, multiple second voltage vectors, multiple third voltage vectors, and multiple fourth voltage vectors, including: calculating a first positive-sequence voltage based on multiple first voltage vectors; calculating a second positive-sequence voltage based on multiple second voltage vectors; calculating a third positive-sequence voltage based on multiple third voltage vectors; calculating a fourth positive-sequence voltage based on multiple fourth voltage vectors; determining a vector difference between the first positive-sequence voltage and the third positive-sequence voltage as a first positive-sequence mutation voltage vector; determining a vector difference between the second positive-sequence voltage and the fourth positive-sequence voltage as a second positive-sequence mutation voltage vector; and calculating the first voltage mutation phase based on the first positive-sequence mutation voltage vector and the second positive-sequence mutation voltage vector.

[0012] In some embodiments, the first voltage mutation phase is a phase difference between a first voltage phase and a second voltage phase, the first voltage phase is a phase of a first positive sequence mutation voltage vector, and the second voltage phase is a phase of a second positive sequence mutation voltage vector.

[0013] In a second aspect, an embodiment of the present application further provides a fault detection device, including:

[0014] The first acquisition module is used to collect multiple first current vectors and multiple first voltage vectors of the first line protection device at a first moment, and to acquire multiple second current vectors and multiple second voltage vectors of the second line protection device, wherein the multiple first current vectors, the multiple first voltage vectors, the multiple second current vectors, and the multiple second voltage vectors all correspond one-to-one to the multi-phase circuit.

[0015] The first calculation module is used to determine a plurality of differential current amplitude mutation amounts according to a plurality of first current vectors and a plurality of second current vectors, and the plurality of differential current amplitude mutation amounts correspond to the multi-phase circuits one by one.

[0016] The second acquisition module is used to obtain multiple third current vectors and multiple third voltage vectors of the first line protection device at the second moment, and obtain multiple fourth current vectors and multiple fourth voltage vectors of the second line protection device at the second moment if there is a first differential current amplitude mutation amount among the multiple differential current amplitude mutation amounts, and the first differential current amplitude mutation amount is greater than the value of a preset differential mutation amount threshold; the multiple third current vectors, the multiple third voltage vectors, the multiple fourth current vectors and the multiple fourth voltage vectors correspond to the multi-phase circuit one by one, the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period.

[0017] The second calculation module is used to determine the phase of the first current mutation amount according to multiple first current vectors, multiple second current vectors, multiple third current vectors and multiple fourth current vectors, and to determine the phase of the first voltage mutation amount according to multiple first voltage vectors, multiple second voltage vectors, multiple third voltage vectors and multiple fourth voltage vectors.

[0018] The output module is used to output a first fault detection result if the first current mutation phase is not in a preset current mutation phase interval and / or the first voltage mutation phase is not in a preset voltage mutation phase interval, wherein the first fault detection result represents a fault in the occurrence area.

[0019] In a third aspect, an embodiment of the present application provides an electronic device, comprising a processor and a memory, wherein the processor is used to execute a computer program stored in the memory to implement a method as described in any one of the first aspects above.

[0020] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and is characterized in that when the computer program is executed by a processor, it implements the method as described in any one of the above-mentioned first aspects.

[0021] In the technical solution provided in the embodiment of the present application, the first line protection device and the second line protection device are in a connected state, and the first line protection device can collect multiple first current vectors and multiple first voltage vectors of the multi-phase circuit in real time, and obtain multiple second current vectors and multiple second voltage vectors of the second line protection device; and calculate the current multiple differential current amplitude mutation amounts. If there is a differential current amplitude mutation amount greater than a preset differential mutation amount threshold value among the multiple differential current amplitude mutation amounts, it can be preliminarily determined that the probability of a line fault is high. The first line protection device can determine the location of the fault through the current mutation phase and the voltage mutation phase, specifically including: obtaining multiple third current vectors and multiple third voltage vectors of the first line protection device at the second moment, and obtaining multiple fourth current vectors and multiple fourth voltage vectors of the second line protection device at the previous moment; the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period; and determining the first current mutation phase according to the multiple first current vectors, the multiple second current vectors, the multiple third current vectors and the multiple fourth current vectors, and determining the first voltage mutation phase according to the multiple first voltage vectors, the multiple second voltage vectors, the multiple third voltage vectors and the multiple fourth voltage vectors; if the first current mutation phase is not in the preset current mutation phase interval, and / or the first voltage mutation phase is not in the preset voltage mutation phase interval, then outputting a first fault detection result, the first fault detection result characterizing the fault in the occurrence area. In the technical solution provided by the embodiment of the present application, the first line protection device can jointly determine whether a circuit fault occurs through the differential current amplitude mutation, the current mutation phase and the voltage mutation phase, and can accurately identify the fault in the area when a fault occurs in the transmission line, thereby improving the sensitivity and accuracy of the fault identification in the area. It can further improve the stability of the power system, protect the safe operation of power equipment, and extend the service life of power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of an application scenario of a fault detection method provided in an embodiment of the present application;

[0024] Figure 2 It is a flowchart of a fault detection method provided by an embodiment of the present application;

[0025] Figure 3It is a differential current waveform schematic diagram of a fault detection method provided in an embodiment of the present application;

[0026] Figure 4 It is a schematic diagram of a fault point of an out-of-area fault in a fault detection method provided in an embodiment of the present application;

[0027] Figure 5 It is a schematic diagram of a fault point of an intra-area fault in a fault detection method provided in an embodiment of the present application;

[0028] Figure 6 is a structural schematic diagram of a fault detection device provided in an embodiment of the present application;

[0029] Figure 7 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0031] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0032] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0034] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0035] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0036] In the power system, the transmission line can transmit the electric energy generated by the power plant to various load centers or user ends through high-voltage, extra-high-voltage or ultra-high-voltage transmission lines after the electric energy is boosted by the booster substation. The safety and stability of the transmission line are crucial to the operation of the power system. The transmission line is usually equipped with a line protection device (also called a "line differential protection device"), which can determine whether the fault occurs within the protected line range (i.e., whether there is an intra-area fault) by detecting the current difference between the two ends of the transmission line. When an intra-area fault is detected, the line protection device cuts off the faulty line to prevent the fault from expanding, thereby protecting the transmission line from damage and ensuring the stable operation of the power system. It can be understood that when an intra-area fault occurs, the line protection device needs to operate correctly, that is, instruct to trip the circuit breakers on both sides of the line to cut off the fault. When the fault location is not within the protection range of the line protection device (i.e., when an out-of-area fault occurs), the line protection device needs to not operate correctly, that is, not output any instructions.

[0037] In the traditional technical solution, the method for the line protection device to distinguish the fault in the area is: first, calculate the multiple differential currents and multiple differential ratio coefficients corresponding to the multi-phase circuits (usually three-phase circuits) on both sides of the line. If the differential current corresponding to any phase circuit in the multi-phase circuit is greater than the preset differential action value, and the corresponding differential ratio coefficient is greater than the preset ratio coefficient value (also called "action ratio coefficient threshold value"), the line protection device determines that an internal fault has occurred. For example, the multi-phase circuit is an A-phase circuit, a B-phase circuit and a C-phase circuit, and the line protection device calculates: the A-phase differential current and the A-phase differential ratio coefficient corresponding to the A-phase circuit, the B-phase differential current and the B-phase differential ratio coefficient corresponding to the B-phase circuit, and the C-phase differential current and the C-phase differential ratio coefficient corresponding to the C-phase circuit. If the A-phase differential current is greater than the preset differential action setting and the A-phase differential ratio coefficient is greater than the preset ratio coefficient value, or the B-phase differential current is greater than the preset differential action setting and the B-phase differential ratio coefficient is greater than the preset ratio coefficient value, or the C-phase differential current is greater than the preset differential action setting and the C-phase differential ratio coefficient is greater than the preset ratio coefficient value, the line protection device determines that an intra-zone fault has occurred.

[0038] The following is combined with Figure 1 Based on the example in , the process of distinguishing faults within the zone in the traditional technical solution is analyzed.

[0039] The differential current is the vector sum of the current vectors collected on both sides of the line.

[0040] For example, Figure 1 A schematic diagram of an application scenario provided by an embodiment of the present application. Figure 1 As shown, in the power system, the transmission line is provided with two identical line protection devices, namely the local line protection device and the opposite line protection device. The local line protection device and the opposite line protection device are respectively connected to the corresponding current transformer (Current Transformer, CT), and the current of the three-phase circuit is obtained through CT. The local line protection device is respectively connected to the local CT1, the local CT2 and the local CT3, and is used to obtain the current of the A phase circuit, the B phase circuit and the C phase circuit. The opposite line protection device is respectively connected to the opposite CT1, the opposite CT2 and the opposite CT3, and is used to obtain the current of the A phase circuit, the B phase circuit and the C phase circuit. Then the differential current corresponding to the A phase circuit is the vector sum of the current vector of the A phase circuit collected by the local CT1 and the current vector of the A phase circuit collected by the opposite CT1.

[0041] The differential ratio coefficient is the ratio between the amplitude of the differential current and the amplitude of the braking current, wherein the braking current is the vector difference of the current vectors collected on both sides of the line.

[0042] For example, Figure 1As shown, the differential ratio coefficient corresponding to the B-phase circuit is the ratio between the differential current corresponding to the B-phase circuit and the braking current corresponding to the B-phase circuit. The differential current corresponding to the B-phase circuit is the vector sum of the current vector of the B-phase circuit collected by the local CT2 and the current vector of the B-phase circuit collected by the opposite CT2. The braking current corresponding to the B-phase circuit is the vector difference between the current vector of the B-phase circuit collected by the local CT2 and the current vector of the B-phase circuit collected by the opposite CT2.

[0043] When a fault occurs in the line, the current vectors collected by the local CT and the opposite CT corresponding to the circuit where the fault occurs have the same current phase. The differential current is the sum of the current vectors collected by the local CT and the opposite CT, and the differential current can meet the condition of being greater than the preset differential action constant. The braking current corresponding to the circuit where the fault occurs is the difference between the current vectors collected by the local CT and the opposite CT. Since the current phases of the current vectors collected by the local CT and the opposite CT are basically the same, the difference between the current vectors is less than the sum of the current vectors. The differential ratio coefficient corresponding to the circuit where the fault occurs is the ratio between the differential current and the braking current. Since the differential current is greater than the braking current, the differential ratio coefficient can meet the condition of being greater than the preset ratio coefficient value.

[0044] However, with the development of the power system, new energy sources have been connected to the power system. The connected new energy sources include controllable power electronic components. When an intra-area fault occurs in the line, the power electronic components will affect the phase of the fault current under the influence of the control strategy. There will be a difference in the current phase of the current vector collected by the local CT and the opposite CT corresponding to the circuit where the intra-area fault occurs. As a result, the differential current cannot meet the condition of being greater than the preset differential action constant, and / or the differential ratio coefficient cannot meet the condition of being greater than the preset ratio coefficient value. The line protection device will not determine that an intra-area fault has occurred at the current moment, and the line protection device cannot control the circuit breaker to trip to isolate the fault current, resulting in an expansion of the fault range. The sensitivity and accuracy of traditional technical solutions for intra-area fault identification of transmission lines are not high.

[0045] In view of this, an embodiment of the present application provides a fault detection method, which can accurately identify the intra-area fault when an intra-area fault occurs in a transmission line, thereby improving the sensitivity and accuracy of intra-area fault identification.

[0046] The technical solution of the embodiments of the present application is described below with reference to the examples in the accompanying drawings.

[0047] like Figure 2 The figure is a flow chart of a fault detection method provided by an embodiment of the present application. The fault detection method provided by the present application may include the following steps:

[0048] Step S201: At a first moment, a plurality of first current vectors and a plurality of first voltage vectors of a first line protection device are collected, and a plurality of second current vectors and a plurality of second voltage vectors of a second line protection device are obtained, wherein the plurality of first current vectors, the plurality of first voltage vectors, the plurality of second current vectors, and the plurality of second voltage vectors all correspond one-to-one to a multi-phase circuit.

[0049] In the embodiment of the present application, when the first line protection device is a local line protection device, the second line protection device may be a remote line protection device. When the first line protection device is a remote line protection device, the second line protection device is a local line protection device. The present application is exemplified by taking the first line protection device as the local line protection device and the second line protection device as the remote line protection device.

[0050] The first line protection device and the second line protection device can be used to monitor the circuit state of the multi-phase circuit. The first line protection device and the second line protection device can be in a connected state. For example, the first line protection device and the second line protection device can be connected through an optical fiber. When the first line protection device is in the optical fiber connection state, it can obtain the current vector and voltage vector collected by the second line protection device.

[0051] The number of current vectors and the number of voltage vectors collected by the first line protection device and the second line protection device at the first moment may be the same as the number of phases of the power transmission line of the power system. Figure 1 As shown, the transmission line of the power system transmission line is a three-phase line, then the number of current vectors and the number of voltage vectors collected by the first line protection device at the first moment are both three, and the number of current vectors and the number of voltage vectors collected by the second line protection device at the first moment are both three.

[0052] In an embodiment of the present application, the first moment may be the current moment, and the first line protection device may collect multiple first current vectors and multiple first voltage vectors in real time, and obtain multiple second current vectors and multiple second voltage vectors of the second line protection device in real time.

[0053] Step S202: determining a plurality of differential current amplitude mutation amounts according to the plurality of first current vectors and the plurality of second current vectors, wherein the plurality of differential current amplitude mutation amounts correspond to the multi-phase circuits one by one.

[0054] After the first line protection device collects a plurality of first current vectors and obtains a plurality of second current vectors collected by the second line protection device, it can determine whether there is a current mutation through the plurality of first current vectors and the plurality of second current vectors.

[0055] The method for calculating multiple differential current amplitude mutation amounts may include the following steps:

[0056] Step A-1: ​​Calculate the first differential current amplitude of the second phase circuit according to the first current vector of the second phase circuit and the second current vector of the second phase circuit, and calculate the second differential current amplitude of the second phase circuit according to the third current vector of the second phase circuit and the fourth current vector of the second phase circuit, the second phase circuit being any phase circuit in the multi-phase circuit.

[0057] The third current vector is the current vector obtained by the first line protection device at the second moment, and the fourth current vector is the current vector obtained by the second line protection device at the second moment. The second moment is a moment before the first moment and separated from the first moment by a preset change period. The preset change period can be the time for the current and voltage cycle to change at the rated frequency of the power system. For example, when the rated frequency of the power system is 50HZ, the current and voltage cycle change time is 20ms, and the preset change period is 20ms.

[0058] For example, Figure 3 A schematic diagram of a differential current waveform of a fault detection method provided in an embodiment of the present application. Figure 3 As shown, when the first moment is T1 and the second moment is T2, the time period between T1 and T2 is the preset change period, and the preset change period is 20ms, that is, the current change period of the differential current is 20ms.

[0059] In the embodiment of the present application, the magnitude of the first differential current amplitude is proportional to the magnitude of the vector sum (sum vector) of the first current vector and the second current vector. The magnitude of the second differential current amplitude is proportional to the magnitude of the vector sum (sum vector) of the third current vector and the fourth current vector. The first differential current amplitude and the second differential current amplitude can be calculated using any existing differential current amplitude calculation method, and the embodiment of the present application is not limited here.

[0060] Step A-2: Calculate the differential current amplitude mutation amount of the second phase circuit according to the first differential current amplitude and the second differential current amplitude. The differential current amplitude mutation amount is the absolute value of the difference between the first differential current amplitude and the second differential current amplitude.

[0061] In an embodiment of the present application, among multiple differential current amplitude mutation amounts, any one differential current amplitude mutation amount can be the absolute value of the difference between the differential current amplitude corresponding to the first moment (i.e., the first differential current amplitude) and the differential current amplitude corresponding to the second moment (i.e., the second differential current amplitude).

[0062] Exemplarily, when the multi-phase circuit is a three-phase circuit (A phase circuit, B phase circuit and C phase circuit respectively), the calculation formulas for the three differential current amplitude mutation amounts corresponding to the three-phase circuit are respectively:

[0063] ΔIda=|Ida(t)-Ida(t-20ms)|;

[0064] ΔIdb=|Idb(t)-Idb(t-20ms)|;

[0065] ΔIdc=|Idc(t)-Idc(t-20ms)|;

[0066] Among them, ΔIda, ΔIdb and ΔIdc represent the differential current amplitude mutations corresponding to the A-phase circuit, the B-phase circuit and the C-phase circuit respectively, Ida(t), Idb(t) and Idc(t) represent the first differential current amplitudes corresponding to the A-phase circuit, the B-phase circuit and the C-phase circuit respectively, Ida(t-20ms), Idb(t-20ms) and Idc(t-20ms) represent the second differential current amplitudes corresponding to the A-phase circuit, the B-phase circuit and the C-phase circuit respectively.

[0067] Step S203: If there is a first differential current amplitude mutation amount among the multiple differential current amplitude mutation amounts, then obtain multiple third current vectors and multiple third voltage vectors of the first line protection device at the second moment, and obtain multiple fourth current vectors and multiple fourth voltage vectors of the second line protection device at the second moment, the first differential current amplitude mutation amount is greater than the value of the preset differential mutation amount threshold, the multiple third current vectors, the multiple third voltage vectors, the multiple fourth current vectors and the multiple fourth voltage vectors correspond to the multi-phase circuit one by one, the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period.

[0068] In the embodiment of the present application, when the transmission line does not have a fault, the differential current amplitude of the transmission line is 0 or close to 0. Therefore, if there is no differential current amplitude mutation greater than the preset differential mutation threshold value among the multiple differential current amplitude mutations, it indicates that the current multi-phase circuit has not had an in-zone fault or the current state of the current multi-phase circuit has stabilized. The first line protection device no longer obtains the judgment of the phase of the current mutation and the voltage mutation to determine the fault location (the fault location includes in-zone faults and out-of-zone faults).

[0069] When a transmission line fails, if it is an intra-zone fault, the differential current amplitude corresponding to the faulty circuit will increase. The absolute value of the difference between the differential current amplitude of the faulty circuit at the first moment and the differential current amplitude at the first moment (differential current amplitude mutation) becomes larger, which can meet the judgment condition of being greater than the preset differential mutation threshold. If it is an out-of-zone fault, since the transmission characteristics of the current transformers on both sides of the transmission line are not completely consistent, the probability of errors in the current vectors collected by the first line protection device and the second line protection device is high. Therefore, among the multiple differential current amplitude mutations calculated by the first line protection device, there may be a differential current amplitude mutation greater than the preset differential mutation threshold. The first line protection device cannot determine whether an intra-zone fault has occurred in the transmission line based only on the judgment factor that there is a differential current amplitude mutation greater than the preset differential mutation threshold among the multiple differential current amplitude mutations.

[0070] The preset differential mutation threshold may be set to 0.01 to 0.05 times the rated current or other values, which is not limited in this application.

[0071] Step S204: determining a first current mutation phase according to a plurality of first current vectors, a plurality of second current vectors, a plurality of third current vectors and a plurality of fourth current vectors, and determining a first voltage mutation phase according to a plurality of first voltage vectors, a plurality of second voltage vectors, a plurality of third voltage vectors and a plurality of fourth voltage vectors.

[0072] In the embodiment of the present application, the method for the first line protection device to determine the phase of the first current mutation amount according to the multiple first current vectors, the multiple second current vectors, the multiple third current vectors and the multiple fourth current vectors may include:

[0073] Step B-1: Calculate a first positive sequence current according to a plurality of first current vectors; calculate a second positive sequence current according to a plurality of second current vectors; calculate a third positive sequence current according to a plurality of third current vectors; and calculate a fourth positive sequence current according to a plurality of fourth current vectors.

[0074] In an embodiment of the present application, the first line protection device can first calculate the first positive sequence current using the symmetrical component method according to the multiple first current vectors. The symmetrical component method is an existing calculation method for power system analysis. The present application can use any positive sequence current calculation method to calculate the first positive sequence current. The present application does not limit this.

[0075] The calculation method of the second positive sequence current, the third positive sequence current and the fourth positive sequence current is the same as the calculation method of the first positive sequence current, and is not elaborated herein in this application.

[0076] Step B-2: Determine the vector difference between the first positive sequence current and the third positive sequence current as the first positive sequence mutation current vector.

[0077] In the embodiment of the present application, the first positive-sequence current and the third positive-sequence current are respectively the positive-sequence currents corresponding to the first line protection device at the first moment and the second moment, and the first positive-sequence mutation current vector is the mutation vector of the positive-sequence current corresponding to the first line protection device in the time period between the second moment and the first moment.

[0078] For example, when the preset change period is 20 ms, the calculation formula of the first positive sequence mutation current vector corresponding to the first line protection device can be:

[0079]

[0080] in, represents the first positive sequence mutation current vector, represents the first positive sequence current, Represents the third positive sequence current.

[0081] Step B-3: Determine the vector difference between the second positive sequence current and the fourth positive sequence current as the second positive sequence mutation current vector.

[0082] In the embodiment of the present application, the second positive-sequence current and the fourth positive-sequence current are respectively the positive-sequence currents corresponding to the second line protection device at the first moment and the second moment, and the second positive-sequence mutation current vector is the mutation vector of the positive-sequence current corresponding to the second line protection device in the time period between the second moment and the first moment.

[0083] The calculation formula of the second positive-sequence mutation current vector is based on the same calculation principle as the calculation formula of the first positive-sequence mutation current vector, and is not elaborated herein in this application.

[0084] Step B-4: Calculate the current mutation phase based on the first positive sequence mutation current vector and the second positive sequence mutation current vector.

[0085] In the embodiment of the present application, the phase of the current mutation amount may be a phase difference between the phase of the first positive-sequence mutation current vector and the phase of the second positive-sequence mutation current vector.

[0086] like Figure 4 FIG. 1 is a schematic diagram of a fault point of an out-of-area fault in a fault detection method provided in an embodiment of the present application. In a power system, when an out-of-area fault occurs in a line, that is, Figure 4When a fault occurs at point F1 in the diagram, the fault point where the fault occurs can be regarded as a fault power source connected to the transmission line in a superimposed manner. Therefore, the first positive-sequence mutation current vector can be used as the fault positive-sequence current generated by the fault point F1 detected by the first line protection device, and the second positive-sequence mutation vector can be used as the fault positive-sequence current generated by the fault point F1 detected by the second line protection device. Because the current transformer at this end and the current transformer at the other end are placed on the same side of the transmission line, the fault positive-sequence current flowing through the current transformer at this end and the current transformer at the other end are the same. The fault positive-sequence current generated by the fault point F1 flows in with the positive polarity of the current transformer at this end (the current transformer connected to the first line protection device) and flows out with the negative polarity, and flows in with the negative polarity of the current transformer at the other end and flows out with the positive polarity (the current transformer connected to the second line protection device). Therefore, when an out-of-zone fault occurs, the phases of the positive-sequence mutation current vectors detected on both sides of the transmission line are opposite. That is, the first positive sequence mutation current vector calculated by the first line protection device is opposite in phase (also called "angle") to the second positive sequence mutation current vector calculated by the second line protection device. The phase difference between the first positive sequence mutation current vector and the second positive sequence mutation current vector should be 180°. If the direction of the current flowing out of the positive polarity of the current transformer is regarded as the positive direction, assuming that the fault positive sequence current generated by the fault point F1 is I f ,but Represents the first positive sequence mutation current vector. Represents the second positive sequence mutation current vector.

[0087] like Figure 5 FIG. 1 is a schematic diagram of a fault point of an intra-area fault in a fault detection method provided in an embodiment of the present application. In a power system, when an intra-area fault occurs in a line, that is, Figure 5 When a fault occurs at point F2 in the diagram, the fault point where the fault occurs can be regarded as a faulty power source connected to the transmission line in a superimposed manner. However, when an in-area fault occurs on the line, the current transformer at this end and the current transformer at the other end are placed on both sides of the transmission line. Therefore, the fault currents flowing through the current transformer at this end and the current transformer at the other end are different. The fault positive-sequence current generated by the fault point F2 flows in from the negative polarity of the current transformer at this end and flows out from the positive polarity. The fault positive-sequence current generated by the fault point F2 also flows in from the negative polarity and flows out from the positive polarity in the current transformer at the other end. Therefore, when an in-area fault occurs, the phases of the positive-sequence mutation current vectors detected on both sides of the transmission line are the same. There is no 180° difference between the phase of the first positive-sequence mutation current vector and the phase of the second positive-sequence mutation current vector. If the direction in which the current flows out from the positive polarity of the current transformer is regarded as the positive direction, assuming that the fault positive-sequence current flowing through the current transformer at this end generated by the fault point F2 is I fM, the fault positive sequence current generated by the fault point F2 flowing through the opposite current transformer is I fN ,but Represents the first positive sequence mutation current vector. Represents the second positive sequence mutation current vector.

[0088] It can be seen from the above that when an out-of-zone fault occurs in the transmission line, the phase of the first positive-sequence mutation current vector is opposite to the phase of the second positive-sequence mutation current vector, and the phase difference should be 180° when there is no error in the current acquisition and calculation process. In the technical solution provided in the embodiment of the present application, in order to avoid the influence of errors in the current acquisition and calculation process on the determination of the fault results within the zone, a preset current mutation phase interval can be set. Exemplarily, the preset current mutation phase interval can be set to an interval of 180°±10°, that is, the preset current mutation phase interval is [170°, 190°]. The preset current mutation phase interval can also be other values, which are not limited in the present application.

[0089] When an out-of-area fault occurs on the transmission line, the phase of the first current mutation should be in the preset current mutation phase interval. When an in-area fault occurs on the transmission line, the phase of the first current mutation should not be in the preset current mutation phase interval.

[0090] In the embodiment of the present application, according to a plurality of first voltage vectors, a plurality of second voltage vectors, a plurality of third voltage vectors, and a plurality of fourth voltage vectors, a method for determining a phase of a first voltage mutation amount may include:

[0091] Step C-1: Calculate a first positive sequence voltage based on multiple first voltage vectors; calculate a second positive sequence voltage based on multiple second voltage vectors; calculate a third positive sequence voltage based on multiple third voltage vectors; calculate a fourth positive sequence voltage based on multiple fourth voltage vectors.

[0092] In the embodiment of the present application, the calculation method of the first positive sequence voltage, the second positive sequence voltage, the third positive sequence voltage and the fourth positive sequence voltage is the same as the calculation method of the first positive sequence current, and is not elaborated herein in the present application.

[0093] Step C-2: Determine the vector difference between the first positive sequence voltage and the third positive sequence voltage as the first positive sequence mutation voltage vector.

[0094] In the embodiment of the present application, the first positive-sequence voltage and the third positive-sequence voltage are respectively the positive-sequence voltages corresponding to the first line protection device at the first moment and the second moment, and the first positive-sequence mutation voltage vector is the mutation vector of the positive-sequence voltage corresponding to the first line protection device in the time period between the second moment and the first moment.

[0095] For example, when the preset change period is 20 ms, the calculation formula of the first positive sequence sudden change voltage vector corresponding to the first line protection device may be:

[0096]

[0097] in, represents the first positive sequence mutation voltage vector, represents the first positive sequence voltage, Represents the third positive sequence voltage.

[0098] Step C-3: Determine the vector difference between the second positive-sequence voltage and the fourth positive-sequence voltage as the second positive-sequence mutation voltage vector.

[0099] In the embodiment of the present application, the second positive-sequence voltage and the fourth positive-sequence voltage are respectively the positive-sequence voltages corresponding to the second line protection device at the first moment and the second moment, and the second positive-sequence mutation voltage vector is the mutation vector of the positive-sequence voltage corresponding to the second line protection device in the time period between the second moment and the first moment.

[0100] The calculation formula of the second positive-sequence mutation voltage vector is based on the same calculation principle as the calculation formula of the first positive-sequence mutation voltage vector, and is not elaborated herein in this application.

[0101] Step C-4: Calculate the phase of the first voltage mutation amount according to the first positive-sequence mutation voltage vector and the second positive-sequence mutation voltage vector.

[0102] In the embodiment of the present application, the phase of the voltage mutation amount may be a phase difference between the phase of the first positive-sequence mutation voltage vector and the phase of the second positive-sequence mutation voltage vector.

[0103] See also Figure 4 In the power system, when a line fault occurs outside the area, that is, Figure 4When a fault occurs at point F1 in the diagram, the fault point where the fault occurs can be regarded as a fault power source superimposed and connected to the transmission line. Therefore, the first positive-sequence mutation voltage vector can be used as the fault positive-sequence voltage generated by the fault point F1 detected by the first line protection device, and the second positive-sequence mutation vector can be used as the fault positive-sequence voltage generated by the fault point F1 detected by the second line protection device. The fault positive-sequence current flowing through the voltage transformer at this end is the same as that flowing through the voltage transformer at the other end. The positive-sequence mutation voltage vector detected on both sides of the transmission line is the ratio between the fault current generated by the fault point F1 and the equivalent impedance. In the power system, the impedance of the transmission line and the equivalent power source is inductive impedance, and the angle of the impedance should be close. Therefore, the phase of the positive-sequence mutation voltage vector detected on both sides of the transmission line should be the same. That is, the first positive-sequence mutation voltage vector calculated by the first line protection device is the same as the phase between the second positive-sequence mutation voltage vector calculated by the second line protection device. The phase difference between the phase of the first positive-sequence mutation voltage vector and the phase of the second positive-sequence mutation voltage vector should be 0°. Then in, represents the first positive sequence mutation voltage vector, Represents the positive sequence component of the fault current, Z M Indicates the equivalent impedance of this end.

[0104] See also Figure 5 In the power system, when a line fault occurs within the area, that is, Figure 5 When a fault occurs at point F2 in the diagram, the fault point where the fault occurs can be regarded as a faulty power source connected to the transmission line. However, when an intra-area fault occurs on the line, the local voltage transformer and the opposite voltage transformer are placed on both sides of the transmission line. Therefore, the fault positive sequence currents flowing through the local voltage transformer and the opposite voltage transformer are different. Therefore, when an intra-area fault occurs, the phase of the positive sequence mutation voltage vector detected on both sides of the transmission line cannot be used as a judgment condition for whether an intra-area fault occurs. The phase difference between the phase of the first positive sequence mutation voltage vector and the phase of the second positive sequence mutation voltage vector does not have a 0° difference.

[0105] It can be seen from the above that when an out-of-area fault occurs in the transmission line, the phase of the first positive-sequence mutation voltage vector is the same as the phase of the second positive-sequence mutation voltage vector, and the phase difference should be 0° when there is no error in the voltage acquisition and calculation process. In the technical solution provided in the embodiment of the present application, in order to avoid the influence of errors in the voltage acquisition and calculation process on the determination of the fault results within the area, a preset voltage mutation phase interval can be set. Exemplarily, the preset voltage mutation phase interval can be set to an interval of 0°±10°, that is, the preset voltage mutation phase interval is [-10°, 10°]. The preset voltage mutation phase interval can also be other values, which are not limited in the present application.

[0106] When an out-of-area fault occurs on the transmission line, the phase of the first voltage mutation amount should be within the preset voltage mutation amount phase interval. When an internal or external fault occurs on the transmission line, the phase of the first voltage mutation amount should not be within the preset voltage mutation amount phase interval.

[0107] Step S205: If the first current mutation phase is not in the preset current mutation phase interval, and / or the first voltage mutation phase is not in the preset voltage mutation phase interval, a first fault detection result is output, and the first fault detection result indicates that a fault has occurred in the region.

[0108] In the embodiment of the present application, the instantaneous judgment condition for the occurrence of an in-zone fault is:

[0109] Judgment condition 1: the first current mutation phase is not within a preset current mutation phase interval.

[0110] Judgment condition 2: the phase of the first voltage mutation is not within the preset voltage mutation phase interval.

[0111] When the first line protection device detects that the current first current mutation phase and / or the first voltage mutation phase meet one of the judgment conditions, or both judgment conditions are met, a first fault detection result is output, and the first fault detection result represents the fault in the occurrence area. Exemplarily, the first fault detection result can be represented as 1, and the embodiment of the present application does not limit the form of the first fault detection result.

[0112] In the technical solution provided in the embodiment of the present application, the first line protection device and the second line protection device are in a connected state, and the first line protection device can collect multiple first current vectors and multiple first voltage vectors of the multi-phase circuit in real time, and obtain multiple second current vectors and multiple second voltage vectors of the second line protection device; and calculate the current multiple differential current amplitude mutation amounts. If there is a differential current amplitude mutation amount greater than a preset differential mutation amount threshold value among the multiple differential current amplitude mutation amounts, it can be preliminarily determined that the probability of a line fault is high. The first line protection device can determine the location of the fault through the current mutation phase and the voltage mutation phase, specifically including: obtaining multiple third current vectors and multiple third voltage vectors of the first line protection device at the second moment, and obtaining multiple fourth current vectors and multiple fourth voltage vectors of the second line protection device at the previous moment; the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period; and determining the first current mutation phase according to the multiple first current vectors, the multiple second current vectors, the multiple third current vectors and the multiple fourth current vectors, and determining the first voltage mutation phase according to the multiple first voltage vectors, the multiple second voltage vectors, the multiple third voltage vectors and the multiple fourth voltage vectors; if the first current mutation phase is not in the preset current mutation phase interval, and / or the first voltage mutation phase is not in the preset voltage mutation phase interval, then outputting a first fault detection result, the first fault detection result characterizing the fault in the occurrence area. In the technical solution provided by the embodiment of the present application, the first line protection device can jointly determine whether a circuit fault occurs through the differential current amplitude mutation, the current mutation phase and the voltage mutation phase, and can accurately identify the fault in the area when a fault occurs in the transmission line, thereby improving the sensitivity and accuracy of the fault identification in the area. It can further improve the stability of the power system, protect the safe operation of power equipment, and extend the service life of power equipment.

[0113] In some embodiments, when the transmission line meets the instantaneous judgment condition of the fault in the occurrence area, a first preset time period can also be set. If the transmission line continues to meet the judgment condition of the fault in the occurrence area within the first preset time period, the first fault detection result is output. Including: obtaining multiple second current mutation phases and multiple second voltage mutation phases within the first preset time period. The starting time of the first preset time period is the first moment, and the first preset time period is less than the preset change cycle. Exemplarily, the first preset time period can be 5ms. If there is a second current mutation phase that is not in the preset current mutation phase interval among the multiple second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among the multiple second voltage mutation phases, the first fault detection result is output.

[0114] The technical solution provided in the embodiment of the present application can improve the reliability of the results of intra-zone fault identification and avoid the impact on the stability of the power system caused by inaccurate instantaneous intra-zone fault identification results.

[0115] In some embodiments, when the transmission line satisfies the judgment condition of the occurrence of an in-zone fault within the first preset time period, multiple differential current amplitudes can also be calculated based on multiple first current vectors and multiple second current vectors. Exemplarily, when the multiple first current vectors include: the first current vector of the A-phase circuit, the first current vector of the B-phase circuit, and the first current vector corresponding to the C-phase circuit, and the multiple second current vectors include: the second current vector of the A-phase circuit, the second current vector of the B-phase circuit, and the second current vector corresponding to the C-phase circuit. Then the differential current amplitude of the A-phase circuit can be calculated based on the first current vector of the A-phase circuit and the second current vector of the A-phase circuit. The differential current amplitude of the B-phase circuit is calculated based on the first current vector of the B-phase circuit and the second current vector of the B-phase circuit. The differential current amplitude of the C-phase circuit is calculated based on the first current vector of the C-phase circuit and the second current vector corresponding to the C-phase circuit. If at least one of the multiple differential current amplitudes is constantly greater than the preset differential current threshold value within the second preset time period, the first fault detection result is output. Exemplarily, when the transmission line meets the judgment condition of the fault in the occurrence area within the first preset time period, if the differential current amplitude of the C-phase circuit is constantly greater than the preset differential current threshold within the second preset time period, the first fault detection result is output. The starting time of the second preset time period is the first moment, and the second preset time period is less than the preset change period. Exemplarily, the second preset time period can be 3ms. The preset differential current threshold can be 0.2 times the rated current of the power system, or other values, which are not limited in this application.

[0116] In the technical solution provided by the embodiment of the present application, after the transmission line meets the judgment condition of the occurrence of an in-zone fault within the first preset time period, it is possible to further determine whether an in-zone fault has occurred by judging the differential current amplitude of the transmission line within the second preset time period. This can improve the reliability and accuracy of the first line protection device in judging in-zone faults.

[0117] It should be understood that, under the premise of no logical conflict, the above-mentioned various application embodiments can be implemented in combination with each other to meet actual application requirements. The specific embodiments or implementation plans obtained after these combinations still fall within the protection scope of this application.

[0118] A fault detection device 60, which may be a first line protection device, is used to monitor the circuit state of a multi-phase circuit, and the first line protection device is in a connected state with a second line protection device. The method includes:

[0119] Corresponding to the fault detection method in the above embodiment, the embodiment of the present application provides a fault detection device 60, which can be a first line protection device. The fault detection device 60 can be implemented by software, hardware or a combination of both to become part or all of a computer device, and is used to execute the steps in the fault detection method in the above embodiment.

[0120] Figure 6 A schematic structural diagram of a fault detection device provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0121] Reference Figure 6 The fault detection device 60 includes a first acquisition module 610 , a first calculation module 620 , a second acquisition module 630 , a second calculation module 640 and an output module 650 .

[0122] The first acquisition module 610 is used to collect multiple first current vectors and multiple first voltage vectors of the first line protection device at a first moment, and to acquire multiple second current vectors and multiple second voltage vectors of the second line protection device, wherein the multiple first current vectors, multiple first voltage vectors, multiple second current vectors, and multiple second voltage vectors all correspond one-to-one to the multi-phase circuit.

[0123] The first calculation module 620 is used to determine a plurality of differential current amplitude mutation amounts according to a plurality of first current vectors and a plurality of second current vectors, wherein the plurality of differential current amplitude mutation amounts correspond to the multi-phase circuits one by one.

[0124] The second acquisition module 630 is used to obtain a plurality of third current vectors and a plurality of third voltage vectors of the first line protection device at the second moment, and to obtain a plurality of fourth current vectors and a plurality of fourth voltage vectors of the second line protection device at the second moment if there is a first differential current amplitude mutation amount among the plurality of differential current amplitude mutation amounts, and the first differential current amplitude mutation amount is greater than a value of a preset differential mutation amount threshold value; the plurality of third current vectors, the plurality of third voltage vectors, the plurality of fourth current vectors and the plurality of fourth voltage vectors correspond one-to-one to the multi-phase circuit, the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period.

[0125] The second calculation module 640 is used to determine the phase of the first current mutation amount according to multiple first current vectors, multiple second current vectors, multiple third current vectors and multiple fourth current vectors, and to determine the phase of the first voltage mutation amount according to multiple first voltage vectors, multiple second voltage vectors, multiple third voltage vectors and multiple fourth voltage vectors.

[0126] The output module 650 is used to output a first fault detection result if the first current mutation phase is not in a preset current mutation phase interval and / or the first voltage mutation phase is not in a preset voltage mutation phase interval, wherein the first fault detection result indicates that a fault has occurred in the region.

[0127] The output module 650 is also used to: obtain multiple second current mutation phases and multiple second voltage mutation phases within a first preset time period, the starting time of the first preset time period is the first time, and the first preset time period is less than the preset change cycle; if there is a second current mutation phase that is not in the preset current mutation phase interval among the multiple second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among the multiple second voltage mutation phases, then output a first fault detection result.

[0128] The output module 650 is also used for: if there is a second current mutation phase that is not in the preset current mutation phase interval among the multiple second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among the multiple second voltage mutation phases, then the corresponding multiple differential current amplitudes are calculated according to the multiple first current vectors and the multiple second current vectors, and the multiple differential current amplitudes correspond to the multi-phase circuits one by one; when there is a first differential current amplitude among the multiple differential current amplitudes, it is determined that the first phase circuit corresponding to the first differential current amplitude has an in-zone fault, the first differential current amplitude is always greater than the preset differential current threshold within the second preset time period, the first phase circuit is one phase circuit in the multi-phase circuit, the starting time of the second preset time period is the first time, and the second preset time period is less than the preset change period.

[0129] The first calculation module 620 is also used to: calculate the first differential current amplitude of the second phase circuit according to the first current vector of the second phase circuit and the second current vector of the second phase circuit, and calculate the second differential current amplitude of the second phase circuit according to the third current vector of the second phase circuit and the fourth current vector of the second phase circuit, the second phase circuit is any one phase circuit in the multi-phase circuit; calculate the differential current amplitude mutation amount of the second phase circuit according to the first differential current amplitude and the second differential current amplitude, the differential current amplitude mutation amount is the absolute value of the difference between the first differential current amplitude and the second differential current amplitude.

[0130] The second calculation module 640 is also used to: calculate the first positive sequence current according to multiple first current vectors; calculate the second positive sequence current according to multiple second current vectors; calculate the third positive sequence current according to multiple third current vectors; calculate the fourth positive sequence current according to multiple fourth current vectors; determine the vector difference between the first positive sequence current and the third positive sequence current as the first positive sequence mutation current vector; determine the vector difference between the second positive sequence current and the fourth positive sequence current as the second positive sequence mutation current vector; calculate the first current mutation phase according to the first positive sequence mutation current vector and the second positive sequence mutation current vector.

[0131] In some embodiments, the first current mutation phase is the phase difference between the first current phase and the second current phase, the first current phase is the phase of the first positive sequence mutation current vector, and the second current phase is the phase of the second positive sequence mutation current vector.

[0132] The second calculation module 640 is also used to: calculate the first positive sequence voltage according to multiple first voltage vectors; calculate the second positive sequence voltage according to multiple second voltage vectors; calculate the third positive sequence voltage according to multiple third voltage vectors; calculate the fourth positive sequence voltage according to multiple fourth voltage vectors; determine the vector difference between the first positive sequence voltage and the third positive sequence voltage as the first positive sequence mutation voltage vector; determine the vector difference between the second positive sequence voltage and the fourth positive sequence voltage as the second positive sequence mutation voltage vector; calculate the first voltage mutation amount phase according to the first positive sequence mutation voltage vector and the second positive sequence mutation voltage vector.

[0133] In some embodiments, the first voltage mutation phase is the phase difference between the first voltage phase and the second voltage phase, the first voltage phase is the phase of the first positive sequence mutation voltage vector, and the second voltage phase is the phase of the second positive sequence mutation voltage vector.

[0134] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0135] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0136] Based on the same inventive concept, an embodiment of the present application also provides an electronic device.

[0137] Figure 7 Schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 7 As shown, the electronic device 70 of this embodiment includes: at least one processor 710 ( Figure 7), a memory 720, and a communication module 740, wherein the memory 720 stores a computer program 730 that may be run on the processor 710. When the processor 710 executes the computer program 730, the steps in the above-mentioned fault detection method embodiment are implemented, such as Figure 2 Alternatively, when the processor 710 executes the computer program 730, the functions of each module / unit in the above-mentioned device embodiments are implemented, for example Figure 6 The functions of the modules 610 to 640 are shown, and the communication module 740 can be a separate communication unit for communicating with an external server or terminal device.

[0138] The electronic device 70 may include, but is not limited to: a processor 710 and a memory 720. Those skilled in the art will appreciate that Figure 7 It is only an example of the electronic device 70 and does not constitute a limitation of the electronic device 70. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 70 may also include an input sending device, a network access device, a bus, etc.

[0139] The processor 710 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0140] In some embodiments, the memory 720 may be an internal storage unit of the electronic device 70, such as a hard disk or memory of the electronic device 70. The memory 720 may also be an external storage device of the electronic device 70, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 70. The memory 720 may also include both an internal storage unit of the electronic device 70 and an external storage device. The memory 720 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as program codes of a computer program 730. The memory 720 may also be used to temporarily store data that has been sent or is to be sent.

[0141] In addition, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0142] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on an electronic device, the electronic device executes the steps in the above-mentioned method embodiments.

[0143] An embodiment of the present application provides a chip, which includes a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, the steps in the above-mentioned method embodiments are implemented.

[0144] An embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps in the above-mentioned method embodiments.

[0145] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0146] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus random access memory (Direct Rambus RAM, DR RAM).

[0147] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0148] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0149] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0150] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the system embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0151] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0152] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0153] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to a large-screen device, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0154] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A fault detection method, characterized in that: Applied to a first line protection device, the first line protection device is used to monitor the circuit state of a multi-phase circuit, the first line protection device is in a connected state with a second line protection device, the method comprises: At a first moment, acquiring a plurality of first current vectors and a plurality of first voltage vectors of the first line protection device, and acquiring a plurality of second current vectors and a plurality of second voltage vectors of the second line protection device, wherein the plurality of first current vectors, the plurality of first voltage vectors, the plurality of second current vectors, and the plurality of second voltage vectors all correspond one-to-one to the multi-phase circuit; Determine a plurality of differential current amplitude mutation amounts according to the plurality of first current vectors and the plurality of second current vectors, wherein the plurality of differential current amplitude mutation amounts correspond to the multi-phase circuits one by one; If there is a first differential current amplitude mutation amount among the multiple differential current amplitude mutation amounts, then obtaining a plurality of third current vectors and a plurality of third voltage vectors of the first line protection device at the second moment, and obtaining a plurality of fourth current vectors and a plurality of fourth voltage vectors of the second line protection device at the second moment, and the first differential current amplitude mutation amount is greater than a value of a preset differential mutation amount threshold; The plurality of third current vectors, the plurality of third voltage vectors, the plurality of fourth current vectors and the plurality of fourth voltage vectors correspond one-to-one to the multi-phase circuit, the second moment is before the first moment, and the time interval between the second moment and the first moment is a preset change period; Determine a first current mutation phase according to the plurality of first current vectors, the plurality of second current vectors, the plurality of third current vectors, and the plurality of fourth current vectors, and determine a first voltage mutation phase according to the plurality of first voltage vectors, the plurality of second voltage vectors, the plurality of third voltage vectors, and the plurality of fourth voltage vectors; If the first current mutation phase is not in a preset current mutation phase interval, and / or the first voltage mutation phase is not in a preset voltage mutation phase interval, a first fault detection result is output, and the first fault detection result indicates that a fault occurs in the area.

2. The fault detection method according to claim 1, characterized in that: The method further comprises: Acquire a plurality of second current mutation phases and a plurality of second voltage mutation phases within a first preset time period, wherein the start time of the first preset time period is the first time, and the first preset time period is less than the preset change period; If there is a second current mutation phase in the multiple second current mutation phases that is not in the preset current mutation phase interval, and / or there is a second voltage mutation phase in the multiple second voltage mutation phases that is not in the preset voltage mutation phase interval, a first fault detection result is output.

3. The fault detection method according to claim 2, characterized in that: If there is a second current mutation phase that is not in the preset current mutation phase interval among the plurality of second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among the plurality of second voltage mutation phases, then outputting a first fault detection result includes: If there is a second current mutation phase that is not in the preset current mutation phase interval among the plurality of second current mutation phases, and / or there is a second voltage mutation phase that is not in the preset voltage mutation phase interval among the plurality of second voltage mutation phases, then a corresponding plurality of differential current amplitudes are calculated according to the plurality of first current vectors and the plurality of second current vectors, and the plurality of differential current amplitudes correspond to the multi-phase circuit one by one; When a first differential current amplitude exists among the multiple differential current amplitudes, it is determined that an in-zone fault occurs in the first phase circuit corresponding to the first differential current amplitude, the first differential current amplitude is constantly greater than a preset differential current threshold value within a second preset time period, the first phase circuit is one phase circuit in the multi-phase circuit, the starting time of the second preset time period is the first time, and the second preset time period is less than the preset change period.

4. The fault detection method according to claim 1, characterized in that: The determining of a plurality of differential current amplitude mutation amounts according to the plurality of first current vectors and the plurality of second current vectors comprises: calculating a first differential current amplitude of the second phase circuit according to a first current vector of the second phase circuit and a second current vector of the second phase circuit, and calculating a second differential current amplitude of the second phase circuit according to a third current vector of the second phase circuit and a fourth current vector of the second phase circuit, wherein the second phase circuit is any one phase circuit of the multi-phase circuit; The differential current amplitude mutation amount of the second phase circuit is calculated according to the first differential current amplitude and the second differential current amplitude, and the differential current amplitude mutation amount is the absolute value of the difference between the first differential current amplitude and the second differential current amplitude.

5. The fault detection method according to claim 4, characterized in that: The determining the phase of the first current mutation amount according to the plurality of first current vectors, the plurality of second current vectors, the plurality of third current vectors and the plurality of fourth current vectors comprises: Calculating a first positive sequence current according to the plurality of first current vectors; calculating a second positive sequence current according to the plurality of second current vectors; calculating a third positive sequence current according to the plurality of third current vectors; calculating a fourth positive sequence current according to the plurality of fourth current vectors; determining a vector difference between the first positive-sequence current and the third positive-sequence current as a first positive-sequence mutation current vector; determining a vector difference between the second positive-sequence current and the fourth positive-sequence current as a second positive-sequence mutation current vector; The first current mutation phase is calculated according to the first positive-sequence mutation current vector and the second positive-sequence mutation current vector.

6. The fault detection method according to claim 5, characterized in that: The first current mutation phase is a phase difference between a first current phase and a second current phase, the first current phase is a phase of the first positive-sequence mutation current vector, and the second current phase is a phase of the second positive-sequence mutation current vector.

7. The fault detection method according to any one of claims 4 to 6, characterized in that: The determining the first voltage mutation phase according to the plurality of first voltage vectors, the plurality of second voltage vectors, the plurality of third voltage vectors and the plurality of fourth voltage vectors comprises: calculating a first positive sequence voltage according to the plurality of first voltage vectors; calculating a second positive sequence voltage according to the plurality of second voltage vectors; calculating a third positive sequence voltage according to the plurality of third voltage vectors; calculating a fourth positive sequence voltage according to the plurality of fourth voltage vectors; determining a vector difference between the first positive-sequence voltage and the third positive-sequence voltage as a first positive-sequence mutation voltage vector; determining a vector difference between the second positive-sequence voltage and the fourth positive-sequence voltage as a second positive-sequence mutation voltage vector; The first voltage mutation phase is calculated according to the first positive-sequence mutation voltage vector and the second positive-sequence mutation voltage vector.

8. The fault detection method according to claim 7, characterized in that: The first voltage mutation phase is a phase difference between a first voltage phase and a second voltage phase, the first voltage phase is a phase of the first positive-sequence mutation voltage vector, and the second voltage phase is a phase of the second positive-sequence mutation voltage vector.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the processor is configured to execute a computer program stored in the memory to implement the method as claimed in any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method as described in any one of claims 1 to 8 is implemented.

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