A method and device for fault line selection analysis based on single-phase asymmetry

Abstract

The present application discloses a method and device for fault line selection analysis based on single-phase asymmetry, which relates to the technical field of power system fault diagnosis, and solves the technical problem that the existing fault line selection analysis method based on single-phase asymmetry makes judgments based on parameters such as overcurrent or voltage mutation, resulting in inaccurate diagnosis or delayed fault processing time in complex network structures or multiple faults. The method comprises: step one: real-time acquisition of current and voltage at target monitoring time points of each phase line; step two: generating preliminary detection results based on current and voltage at target monitoring time points of each phase line; step three: when the preliminary detection result shows that there is a risk of fault, determining the fault phase line in the three-phase circuit to be analyzed based on the fault characteristic parameters of each phase line; step four: analyzing the fault type and fault location of the fault phase line; step five: sending the fault to the power grid control center or maintenance personnel through the communication network; effectively improving the reliability and safety of the power system.

Description

Technical Field

[0001] The present application belongs to the technical field of power system fault diagnosis, and relates to power system fault diagnosis technology, and specifically to a fault line selection analysis method and device based on single-phase asymmetry. Background Art

[0002] In power systems, transmission line faults are common problems, especially asymmetric short circuit faults in three-phase circuits. Such faults can have a serious impact on the stability and safety of power systems. Traditional fault line selection methods are mostly based on parameters such as overcurrent or voltage mutation, but these methods are prone to misjudgment in complex network structures or multiple fault situations.

[0003] In the current three-phase circuit fault line screening process, there are still some defects and disadvantages, which may lead to inaccurate diagnosis or delay the time of fault handling. First of all, the traditional three-phase circuit fault line screening method mainly relies on manual inspection and test instrument measurement, which has the following major defects:

[0004] 1. Reliance on manual judgment: Traditional methods usually require technicians to manually inspect and test the circuit, which is subjective and has the risk of misjudgment. The experience and level of technicians may vary, resulting in deviations in fault judgment and affecting the accuracy of fault diagnosis.

[0005] 2. Time consumption: Manual inspection and testing requires a lot of time and human resources, especially for complex circuit systems, which may require repeated testing and troubleshooting, which takes a long time. This method is not only inefficient, but may also delay the time for troubleshooting and increase the loss of production downtime.

[0006] 3. Difficult to cope with large-scale systems: For large-scale three-phase circuit systems, manual inspection and testing are less efficient, and it is difficult to achieve full coverage and quickly locate faulty lines. In this case, missed detection or wrong detection may occur, resulting in untimely or incorrect fault handling.

[0007] 4. Restrictions on fault types: Traditional methods may only be applicable to the diagnosis of some fault types. For some complex or hidden faults, manual methods are often unable to accurately judge. This limits the comprehensiveness and accuracy of fault diagnosis. Summary of the invention

[0008] The present application aims to solve at least one of the technical problems existing in the prior art; to this end, the present application proposes a fault line selection analysis method and device based on single-phase asymmetry, which is used to solve the technical problems of inaccurate diagnosis or delayed fault processing time in the existing fault line selection analysis method based on single-phase asymmetry due to the judgment based on parameters such as overcurrent or voltage mutation in complex network structures or multiple faults. The present application collects the current and voltage of each phase line in the three-phase circuit to be analyzed at the target monitoring time point in real time, calculates the imbalance in the three-phase circuit to be analyzed, and then preliminarily determines whether there is a phase line fault in the three-phase circuit to be analyzed. If it is preliminarily determined that there is a faulty phase line in the three-phase circuit to be analyzed, the fault characteristic parameters of each phase line in the three-phase circuit to be analyzed are further extracted, and the possible fault coefficients of each phase line in the three-phase circuit to be analyzed are deeply analyzed, and finally the fault phase line in the three-phase circuit to be analyzed is determined, and finally the fault type and fault location of the fault phase line in the three-phase circuit to be analyzed are analyzed to solve the above problems.

[0009] To achieve the above objectives, the first aspect of the present application provides a fault line selection analysis method based on single-phase asymmetry, comprising:

[0010] Step 1: Install current and voltage sensors in each phase line of the three-phase circuit to be analyzed to collect the current and voltage of each phase line at the target monitoring time point in real time;

[0011] Step 2: Based on the current and voltage of each phase line at the target monitoring time point, calculate the imbalance degree in the three-phase circuit to be analyzed, and generate a preliminary detection result based on the imbalance degree;

[0012] Step 3: When the preliminary detection result shows that there is a fault risk, the fault characteristic parameters of each phase line are extracted, based on which the fault possibility coefficient of each phase line is generated, and the fault phase line in the three-phase circuit to be analyzed is determined;

[0013] Step 4: Analyze the fault phase line in the three-phase circuit to be analyzed, and then obtain the fault type and fault location of the fault phase line in the three-phase circuit to be analyzed;

[0014] Step 5: Send relevant information of the faulty phase line to the power grid control center or maintenance personnel, that is, send the number of the faulty phase line in the three-phase circuit to be analyzed, the fault type and the fault location point to the power grid control center or maintenance personnel through the communication network; the relevant information includes the number of the faulty phase line, the fault type and the fault location point, etc.

[0015] Preferably, calculating the imbalance degree in the three-phase circuit to be analyzed based on the current and voltage of each phase line at a target monitoring time point includes:

[0016] Obtain the current and voltage of each phase line in the three-phase circuit to be analyzed at the target monitoring time point, and mark them as as well as , h represents the number of each phase line, and the specific value of h is a, b, c;

[0017] By analyzing the formula , the average phase voltage in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the voltage unbalance rate VUR in the three-phase circuit to be analyzed is obtained by analysis, where: , and Respectively represent the voltages of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0018] By analyzing the formula , the average phase current in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the current unbalance rate CUR in the three-phase circuit to be analyzed is obtained by analysis, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0019] By formula The unbalance degree UI in the three-phase circuit to be analyzed is calculated. Preferably, the generating of the preliminary detection result based on the unbalance degree includes:

[0020] Obtain the imbalance UI in the three-phase circuit to be analyzed; determine whether the imbalance UI is greater than the three-phase circuit imbalance threshold; if yes, set the preliminary detection result as having a fault risk; if no, set the preliminary detection result as having no fault risk; wherein the preliminary detection result includes a fault risk and a no fault risk.

[0021] Preferably, the fault characteristic parameters include voltage change rate, current mutation value and voltage harmonic amplitude; wherein the voltage change rate is obtained by the following steps:

[0022] By installing a voltage sensor in each phase line corresponding to the three-phase circuit to be analyzed, the voltage value of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point is obtained;

[0023] The voltage values ​​of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point are imported into the oscilloscope to obtain the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed corresponding to the real-time monitoring time point, and the time points of each peak corresponding to the real-time monitoring time point in the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed are screened out, and the difference calculation is performed, and the result of the difference calculation is averaged to obtain the mean time interval of the peak of the voltage waveform diagram corresponding to each phase line in the three-phase circuit to be analyzed. , through the formula Calculate the voltage angular frequency of each phase line in the three-phase circuit to be analyzed ;

[0024] Extract the voltage waveform of the A phase line in the three-phase circuit to be analyzed at the real-time monitoring time point from the voltage waveform of each phase line in the three-phase circuit to be analyzed at the real-time monitoring time point, and select the voltage value at t=0 as the reference voltage value, where t represents the number of each real-time monitoring time point;

[0025] Import reference voltage value into known waveform equation In the example, at t=0:

[0026] ,in, Indicates the peak voltage values ​​of the A phase line in the three-phase circuit to be analyzed at the corresponding real-time monitoring time point, i represents the number of each peak, i=1, 2, ..., m; m is the total number of peaks; is the voltage angular frequency of phase A in the three-phase circuit to be analyzed; is the voltage phase angle of phase A in the three-phase circuit to be analyzed;

[0027] Will and The two equations are solved together to obtain the voltage phase angle of phase A in the three-phase circuit to be analyzed. ;

[0028] By formula Calculate the voltage phase angle of phase B in the three-phase circuit to be analyzed; Calculate and obtain the voltage phase angle of the C phase line in the three-phase circuit to be analyzed;

[0029] The maximum voltage value corresponding to each phase line in the three-phase circuit to be analyzed is selected from the voltage values ​​corresponding to each real-time monitoring time point of each phase line in the three-phase circuit to be analyzed. , obtain the mathematical model of the instantaneous voltage of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point; the mathematical model is , and derive it , get the voltage change rate of each phase line in the three-phase circuit to be analyzed .

[0030] Preferably, the current mutation value and voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed are obtained by the following steps:

[0031] Step 1: Obtain the current of each phase line in the three-phase circuit to be analyzed at the target monitoring time point and voltage ; Through the conversion formula Convert the current of each phase line into the corresponding phase current ; Through the conversion formula Convert the voltage of each phase line into the corresponding phase voltage ;

[0032] By formula Calculate the coil inductance value of each phase line in the three-phase circuit to be analyzed at the target monitoring time point. represents the circuit frequency of the hth phase line in the predefined three-phase circuit to be analyzed;

[0033] By formula Calculate and obtain the sudden change value of the current of each phase line in the three-phase circuit to be analyzed;

[0034] Step 2: Extract the voltage signal value of each harmonic of the voltage waveform corresponding to each phase line in the three-phase circuit to be analyzed from the voltage waveform corresponding to the real-time monitoring time point of each phase line in the three-phase circuit to be analyzed And the period to which each harmonic corresponds to the voltage signal value , n represents the number of each harmonic, which is obtained by integration:

[0035] ,

[0036] in, It is represented as the real-time monitoring time point of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed. They respectively represent the cosine and sine functions of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed;

[0037] By calculation , get the amplitude of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed The harmonic quantities are summed and averaged to obtain the voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed.

[0038] Preferably, in step 3, the fault phase line in the three-phase circuit to be analyzed is determined, and the specific determination operation is:

[0039] The fault possibility coefficient of each phase line in the three-phase circuit to be analyzed is compared with the predefined phase line fault reference coefficient. If there is a phase line in the three-phase circuit to be analyzed whose fault possibility coefficient is greater than the predefined phase line fault reference coefficient, the phase line is marked as a faulty phase line, thereby determining the faulty phase line in the three-phase circuit to be analyzed.

[0040] Preferably, generating the possible fault coefficient of each phase line based on the fault characteristic parameters of each phase line includes:

[0041] Get the voltage change rate of each phase line in the three-phase circuit to be analyzed , Current mutation value And the voltage harmonic amplitude ;

[0042] Comprehensive analysis obtains the possible fault coefficient of each phase line in the three-phase circuit to be analyzed , where c1, c2 and c3 represent the weight factors of the predefined voltage change rate, current mutation value and voltage harmonic amplitude corresponding to the possible fault coefficient, respectively. , and They represent the pre-planned allowable voltage change rate difference, allowable current mutation difference and allowable voltage harmonic change difference respectively. , and They respectively represent the voltage change rate threshold, current mutation threshold and voltage harmonic change threshold of the hth phase line in the three-phase circuit to be analyzed stored in the database.

[0043] Preferably, analyzing and obtaining the fault type of the faulty phase line in the three-phase circuit to be analyzed includes:

[0044] By breaking down the formula , decompose to obtain the negative sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ,in, To indicate a plural unit, ; e is a natural constant, j represents an imaginary unit, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0045] By breaking down the formula Decompose and obtain the positive sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ;

[0046] Get the zero-sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ;

[0047] According to the current sensors installed in the phase lines corresponding to the three-phase circuit to be analyzed, the current at each monitoring time point before the target monitoring time point corresponding to the three-phase circuit to be analyzed is monitored, and the negative-sequence, positive-sequence, and zero-sequence current components at each monitoring time point before the target monitoring time point corresponding to the three-phase circuit to be analyzed are calculated in the same way according to the above calculation method, and they are sorted with the negative-sequence, positive-sequence, and zero-sequence current components at the target monitoring time point corresponding to the three-phase circuit to be analyzed, and they are integrated to obtain the negative-sequence, positive-sequence, and zero-sequence current component sets at the monitoring time points corresponding to the three-phase circuit to be analyzed;

[0048] Filter out the negative sequence current components of the three-phase circuit to be analyzed corresponding to each monitoring time point from the above set , s represents the number of each monitoring time point, s=1, 2, ..., y, y is the total number of negative sequence current components in the negative sequence current component set; the analysis results show the negative sequence current component change coefficient corresponding to each monitoring time point of the three-phase circuit to be analyzed , are the negative sequence current components of the three-phase circuit to be analyzed corresponding to the s+1th and s-1th monitoring time points respectively;

[0049] According to the calculation method of the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point, the positive sequence current component variation coefficient and the zero sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point are calculated in the same way;

[0050] If the zero-sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient, and the positive-sequence current component variation coefficient and the negative-sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point are both less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a single-phase grounding fault;

[0051] If the positive sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient, and the zero sequence current component variation coefficient and the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point are both less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a three-phase short circuit fault;

[0052] If the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient and the zero sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a two-phase grounding fault;

[0053] If the zero-sequence current component variation coefficient and the negative-sequence current component variation coefficient corresponding to a certain monitoring time point of the three-phase circuit to be analyzed are both greater than the predefined current component variation reference coefficient, the fault type of the faulty phase line in the three-phase circuit to be analyzed is determined to be a two-phase to ground short circuit fault.

[0054] Preferably, analyzing the fault position point of the fault phase line in the three-phase circuit to be analyzed includes:

[0055] Obtain the fault time point of the fault phase line in the three-phase circuit to be analyzed, and then obtain the voltage and current at the line start point and line end point of the fault phase line in the three-phase circuit to be analyzed corresponding to the fault time point through the installed sensors;

[0056] A virtual model diagram of the fault phase line in the three-phase circuit to be analyzed is obtained, and then a fault simulation is performed on the virtual model diagram of the fault phase line in the three-phase circuit to be analyzed. The specific simulation process is as follows:

[0057] Assuming that the fault location point occurs at a distance x from the starting point of the fault phase line, the distance from the fault location point to the starting point of the line is x;

[0058] By solving the equation , get the actual distance x of the fault location;

[0059] in They represent the voltage and current at the starting point of the line at the time of the fault corresponding to the fault in the three-phase circuit to be analyzed. They represent the voltage and current at the end of the line at the time point corresponding to the fault of the fault phase line in the three-phase circuit to be analyzed, and Z represents the impedance per unit length of the circuit;

[0060] Extract the resistance R and reactance X of the fault phase line in the three-phase circuit to be analyzed from the database, and calculate the impedance per unit length of the fault phase line in the three-phase circuit to be analyzed ;

[0061] The position of the fault location point is imported into the virtual model diagram of the fault phase line in the three-phase circuit to be analyzed, thereby obtaining the fault location point of the fault phase line in the three-phase circuit to be analyzed.

[0062] Another aspect of the present application provides a single-phase asymmetry-based fault line selection and analysis device, comprising an electronic device and a computer-readable storage medium;

[0063] The electronic device comprises a processor, a memory and a communication bus, wherein the memory stores a computer-readable program executable by the processor;

[0064] The communication bus realizes the connection and communication between the processor and the memory;

[0065] When the processor executes the computer readable program, the processor implements the steps in a fault line selection analysis method based on single-phase asymmetry;

[0066] The computer-readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in a fault line selection analysis method based on single-phase asymmetry.

[0067] Compared with the prior art, the beneficial effects of this application are:

[0068] 1. The present invention provides a fault line selection analysis method based on single-phase asymmetry. By installing current and voltage sensors in the corresponding phase lines of the three-phase circuit to be analyzed, the current and voltage of each phase line in the three-phase circuit to be analyzed corresponding to the target monitoring time point are collected in real time, and the imbalance degree in the three-phase circuit to be analyzed is calculated, and then a preliminary judgment is made as to whether there is a phase line fault in the three-phase circuit to be analyzed. If it is preliminarily judged that there is a faulty phase line in the three-phase circuit to be analyzed, the fault characteristic parameters of each phase line in the three-phase circuit to be analyzed are further extracted, and the possible fault coefficients of each phase line in the three-phase circuit to be analyzed are deeply analyzed, and finally the fault phase line in the three-phase circuit to be analyzed is determined, and finally the fault type and fault location point of the fault phase line in the three-phase circuit to be analyzed are analyzed, which effectively solves the current problem of defects and drawbacks in screening fault lines in three-phase circuits, can effectively improve the reliability and safety of the power system, and has important practical value for the maintenance and management of the power system. At the same time, by timely discovering and handling faults, the system can maintain stable operation and avoid system collapse or fault chain effects caused by faults.

[0069] 2. The embodiments of the present invention avoid the errors caused by subjective judgment, can locate the faulty line more objectively and accurately, and improve the accuracy and reliability of fault diagnosis. At the same time, this efficient diagnosis method can reduce production downtime, improve production efficiency, reduce the time and cost of fault handling, and bring many benefits to circuit operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0071] Figure 1 A schematic diagram of the method steps of a fault line selection analysis method based on single-phase asymmetry of the present application;

[0072] Figure 2This is a schematic diagram of the fault type analysis steps in this application;

[0073] Figure 3 This is a schematic diagram of the device structure of this application. DETAILED DESCRIPTION

[0074] The technical solution of the present application will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0075] Example 1

[0076] See also Figure 1 As shown, a fault line selection analysis method based on single-phase asymmetry includes the following steps:

[0077] Step 1: Install current and voltage sensors in each phase line of the three-phase circuit to be analyzed to collect the current and voltage of each phase line at the target monitoring time point in real time;

[0078] Step 2: Based on the current and voltage of each phase line at the target monitoring time point, calculate the imbalance degree in the three-phase circuit to be analyzed, and generate a preliminary detection result based on the imbalance degree;

[0079] In a preferred solution of the present application, the unbalance degree in the three-phase circuit to be analyzed is calculated in step 2, and the specific process is as follows:

[0080] Obtain the current and voltage of each phase line in the three-phase circuit to be analyzed at the target monitoring time point, and mark them as as well as , h represents the number of each phase line, and the specific value of h is a, b, c;

[0081] By analyzing the formula , the average phase voltage in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the voltage unbalance rate VUR in the three-phase circuit to be analyzed is obtained by analysis, where: , and Respectively represent the voltages of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0082] By analyzing the formula , the average phase current in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the current unbalance rate CUR in the three-phase circuit to be analyzed is obtained by analysis, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0083] By formula The unbalance degree UI in the three-phase circuit to be analyzed is calculated.

[0084] Generate preliminary test results based on the imbalance, including:

[0085] Obtain the imbalance UI in the three-phase circuit to be analyzed; determine whether the imbalance UI is greater than the three-phase circuit imbalance threshold; if yes, it indicates that there is a phase line fault in the three-phase circuit to be analyzed, and the preliminary detection result is set to have a fault risk; if no, it indicates that there is no phase line fault in the three-phase circuit to be analyzed, and the preliminary detection result is set to have no fault risk; wherein the preliminary detection result includes a fault risk and a no fault risk.

[0086] It should be noted that in an ideal three-phase system, the phases should be balanced, that is, their voltages and currents should be equal. If an imbalance occurs, it may be due to a fault in one of the phase lines, such as poor contact, open circuit or short circuit, resulting in uneven voltage or current distribution. Therefore, when the imbalance exceeds a predefined threshold, this may indicate that there is a phase line fault in the three-phase circuit, requiring further inspection and maintenance.

[0087] Step 3: When the preliminary detection result shows that there is a fault risk, the fault characteristic parameters of each phase line are extracted, based on which the fault possibility coefficient of each phase line is generated, and the fault phase line in the three-phase circuit to be analyzed is determined;

[0088] In a preferred solution of the present application, the fault characteristic parameters include the voltage change rate, the current mutation value and the voltage harmonic amplitude; the fault characteristic parameters of each phase line in the three-phase circuit to be analyzed are extracted, and the specific process is as follows:

[0089] The voltage change rate of each phase line in the three-phase circuit to be analyzed is obtained by the following method:

[0090] By installing a voltage sensor in each phase line corresponding to the three-phase circuit to be analyzed, the voltage value of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point is obtained;

[0091] The voltage values ​​of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point are imported into the oscilloscope to obtain the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed corresponding to the real-time monitoring time point, and the time points of each peak corresponding to the real-time monitoring time point in the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed are screened out, and the difference calculation is performed, and the result of the difference calculation is averaged to obtain the mean time interval of the peak of the voltage waveform diagram corresponding to each phase line in the three-phase circuit to be analyzed. , through the formula Calculate the voltage angular frequency of each phase line in the three-phase circuit to be analyzed ;

[0092] Extract the voltage waveform of the A phase line in the three-phase circuit to be analyzed at the real-time monitoring time point from the voltage waveform of each phase line in the three-phase circuit to be analyzed at the real-time monitoring time point, and select the voltage value at t=0 as the reference voltage value, where t represents the number of each real-time monitoring time point;

[0093] Import reference voltage value into known waveform equation In the example, at t=0:

[0094] ,in, Indicates the peak voltage values ​​of the A phase line in the three-phase circuit to be analyzed at the corresponding real-time monitoring time point, i represents the number of each peak, i=1, 2, ..., m; m is the total number of peaks; is the voltage angular frequency of phase A in the three-phase circuit to be analyzed; is the voltage phase angle of phase A in the three-phase circuit to be analyzed;

[0095] Will and The two equations are solved together to obtain the voltage phase angle of phase A in the three-phase circuit to be analyzed. ;

[0096] By formula Calculate the voltage phase angle of phase B in the three-phase circuit to be analyzed; Calculate and obtain the voltage phase angle of the C phase line in the three-phase circuit to be analyzed;

[0097] The maximum voltage value corresponding to each phase line in the three-phase circuit to be analyzed is selected from the voltage values ​​corresponding to each real-time monitoring time point of each phase line in the three-phase circuit to be analyzed. , obtain the mathematical model of the instantaneous voltage of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point; the mathematical model is , and derive it , get the voltage change rate of each phase line in the three-phase circuit to be analyzed .

[0098] The current mutation value of each phase line in the three-phase circuit to be analyzed is obtained by the following method:

[0099] Get the current of each phase line in the three-phase circuit to be analyzed at the target monitoring time point and voltage ; Through the conversion formula Convert the current of each phase line into the corresponding phase current ; Through the conversion formula Convert the voltage of each phase line into the corresponding phase voltage ;

[0100] By formula Calculate the coil inductance value of each phase line in the three-phase circuit to be analyzed at the target monitoring time point. represents the circuit frequency of the hth phase line in the predefined three-phase circuit to be analyzed;

[0101] By formula Calculate and obtain the sudden change value of the current of each phase line in the three-phase circuit to be analyzed;

[0102] The voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed is obtained by the following method:

[0103] Extract the voltage signal value of each harmonic of the voltage waveform corresponding to each phase line in the three-phase circuit to be analyzed from the voltage waveform corresponding to the real-time monitoring time point of each phase line in the three-phase circuit to be analyzed And the period to which each harmonic corresponds to the voltage signal value , n represents the number of each harmonic, which is obtained by integration:

[0104] in, It is represented as the real-time monitoring time point of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed. They respectively represent the cosine and sine functions of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed;

[0105] By calculation , get the amplitude of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed The harmonic quantities are summed and averaged to obtain the voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed.

[0106] In a preferred solution of the present application, in step 3, the possible fault coefficient of each phase line in the three-phase circuit to be analyzed is deeply analyzed, and the specific analysis process includes:

[0107] Get the voltage change rate of each phase line in the three-phase circuit to be analyzed , Current mutation value And the voltage harmonic amplitude ;

[0108] Comprehensive analysis obtains the possible fault coefficient of each phase line in the three-phase circuit to be analyzed , where c1, c2 and c3 represent the weight factors of the predefined voltage change rate, current mutation value and voltage harmonic amplitude corresponding to the possible fault coefficient, respectively. , and They represent the pre-planned allowable voltage change rate difference, allowable current mutation difference and allowable voltage harmonic change difference respectively. , and They respectively represent the voltage change rate threshold, current mutation threshold and voltage harmonic change threshold of the hth phase line in the three-phase circuit to be analyzed stored in the database.

[0109] In a preferred solution of the present application, in step 3, the fault phase line in the three-phase circuit to be analyzed is determined, and the specific determination operation is:

[0110] The fault possibility coefficient of each phase line in the three-phase circuit to be analyzed is compared with the predefined phase line fault reference coefficient. If there is a phase line in the three-phase circuit to be analyzed whose fault possibility coefficient is greater than the predefined phase line fault reference coefficient, the phase line is marked as a faulty phase line, thereby determining the faulty phase line in the three-phase circuit to be analyzed.

[0111] See also Figure 2 , step 4, analyzing the fault phase line in the three-phase circuit to be analyzed, and then analyzing to obtain the fault type and fault location of the fault phase line in the three-phase circuit to be analyzed;

[0112] In a preferred solution of the present application, the fault type of the faulty phase line in the three-phase circuit to be analyzed is obtained in step 4, and the analysis process is as follows:

[0113] By breaking down the formula , decompose to obtain the negative sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ,in, To indicate a plural unit, , e is a natural constant, j represents an imaginary unit, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point;

[0114] By breaking down the formula , decompose to obtain the positive sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ;

[0115] Get the zero-sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ;

[0116] According to the current sensors installed in the phase lines corresponding to the three-phase circuit to be analyzed, the current at each monitoring time point before the target monitoring time point corresponding to the three-phase circuit to be analyzed is monitored, and the negative-sequence, positive-sequence, and zero-sequence current components at each monitoring time point before the target monitoring time point corresponding to the three-phase circuit to be analyzed are calculated in the same way according to the above calculation method, and they are sorted with the negative-sequence, positive-sequence, and zero-sequence current components at the target monitoring time point corresponding to the three-phase circuit to be analyzed, and they are integrated to obtain the negative-sequence, positive-sequence, and zero-sequence current component sets at the monitoring time points corresponding to the three-phase circuit to be analyzed;

[0117] Filter out the negative sequence current components of the three-phase circuit to be analyzed corresponding to each monitoring time point from the above set , s represents the number of each monitoring time point, s=1, 2, ..., y, y is the total number of negative sequence current components in the negative sequence current component set; the analysis results show the negative sequence current component change coefficient corresponding to each monitoring time point of the three-phase circuit to be analyzed , are the negative sequence current components of the three-phase circuit to be analyzed corresponding to the s+1th and s-1th monitoring time points respectively;

[0118] According to the calculation method of the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point, the positive sequence current component variation coefficient and the zero sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point are calculated in the same way;

[0119] If the zero-sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient, and the positive-sequence current component variation coefficient and the negative-sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point are both less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a single-phase grounding fault;

[0120] If the positive sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient, and the zero sequence current component variation coefficient and the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point are both less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a three-phase short circuit fault;

[0121] If the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is greater than the predefined current component variation reference coefficient and the zero sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to a certain monitoring time point is less than the predefined current component variation reference coefficient, then the fault type of the fault phase line in the three-phase circuit to be analyzed is determined to be a two-phase grounding fault;

[0122] If the zero-sequence current component variation coefficient and the negative-sequence current component variation coefficient corresponding to a certain monitoring time point of the three-phase circuit to be analyzed are both greater than the predefined current component variation reference coefficient, the fault type of the faulty phase line in the three-phase circuit to be analyzed is determined to be a two-phase to ground short circuit fault.

[0123] In this embodiment, the current of each phase line of the three-phase circuit to be analyzed at the corresponding target monitoring time point is obtained; the corresponding negative-sequence current component, positive-sequence current component and zero-sequence current component are obtained based on the current analysis of each phase line; the negative-sequence current component, positive-sequence current component and zero-sequence current component of each monitoring time point before the target monitoring time point are calculated; the negative-sequence current component, positive-sequence current component and zero-sequence current component corresponding to the target monitoring time point and each monitoring time point are respectively integrated into a negative-sequence current component set, a positive-sequence current component set and a zero-sequence current component set; the negative-sequence current component variation coefficient of each monitoring time point is calculated according to each negative-sequence current component in the negative-sequence current component set; the positive-sequence current component variation coefficient of each monitoring time point is calculated according to each positive-sequence current component in the positive-sequence current component set; the zero-sequence current component variation coefficient of each monitoring time point is calculated according to each zero-sequence current component in the zero-sequence current component set; the corresponding fault type is obtained according to the negative-sequence current component variation coefficient, the positive-sequence current component variation coefficient and the zero-sequence current component variation coefficient at each monitoring time point.

[0124] In a preferred solution of the present application, the fault position point of the fault phase line in the three-phase circuit to be analyzed is obtained in step 4, and the analysis process is as follows:

[0125] Obtain the fault time point of the fault phase line in the three-phase circuit to be analyzed, and then obtain the voltage and current at the line start point and line end point of the fault phase line in the three-phase circuit to be analyzed corresponding to the fault time point through the installed sensors;

[0126] It should be added that, when analyzing the fault type of the faulty phase line in the three-phase circuit, if the fault type is determined at a certain monitoring time point corresponding to the three-phase circuit to be analyzed, the monitoring time point is recorded as the fault time point.

[0127] A virtual model diagram of the fault phase line in the three-phase circuit to be analyzed is obtained, and then a fault simulation is performed on the virtual model diagram of the fault phase line in the three-phase circuit to be analyzed. The specific simulation process is as follows:

[0128] Assuming that the fault location point occurs at a distance x from the starting point of the fault phase line, the distance from the fault location point to the starting point of the line is x;

[0129] By solving the equation , get the actual distance x of the fault location;

[0130] in They represent the voltage and current at the starting point of the line at the time of the fault corresponding to the fault in the three-phase circuit to be analyzed. They represent the voltage and current at the end of the line at the time point corresponding to the fault of the fault phase line in the three-phase circuit to be analyzed, and Z represents the impedance per unit length of the circuit;

[0131] Extract the resistance R and reactance X of the fault phase line in the three-phase circuit to be analyzed from the database, and calculate the impedance per unit length of the fault phase line in the three-phase circuit to be analyzed ;

[0132] The position of the fault location point is imported into the virtual model diagram of the fault phase line in the three-phase circuit to be analyzed, thereby obtaining the fault location point of the fault phase line in the three-phase circuit to be analyzed.

[0133] Step 5: Send the number of the fault phase line in the three-phase circuit to be analyzed, the fault type and the fault location point to the power grid control center or maintenance personnel through the communication network.

[0134] Example 2

[0135] See also Figure 3 , according to an exemplary embodiment, a fault line selection and analysis device based on single-phase asymmetry is shown, including: an electronic device and a computer-readable storage medium;

[0136] It is a structural schematic diagram of a fault line selection and analysis device based on single-phase asymmetry provided in an embodiment of the present application. The device may have relatively large differences due to different configurations or performances, and can include one or more processors (Central Processing Units, CPU) and one or more memories, wherein at least one computer program is stored in the memory, and the at least one computer program is loaded and executed by the processor to implement the above-mentioned fault line selection and analysis method based on single-phase asymmetry.

[0137] The electronic device comprises a processor, a memory and a communication bus, wherein the memory stores a computer-readable program executable by the processor;

[0138] The communication bus realizes the connection and communication between the processor and the memory;

[0139] The processor implements the above-mentioned fault line selection analysis method based on single-phase asymmetry by calling the computer program stored in the memory and executing the computer readable program;

[0140] The computer-readable storage medium stores one or more programs. When executed on an electronic device, the one or more programs can be executed by one or more processors, providing a user input interface to implement the above-mentioned fault line selection analysis method based on single-phase asymmetry.

[0141] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes 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.

[0142] It should be understood that determining B based on A does not mean determining B only based on A. B can also be determined based on A and / or other information.

[0143] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0144] How this application works:

[0145] The present invention provides a fault line selection analysis method based on single-phase asymmetry. By installing current and voltage sensors in the corresponding phase lines of the three-phase circuit to be analyzed, the current and voltage of each phase line in the three-phase circuit to be analyzed corresponding to the target monitoring time point are collected in real time, and the imbalance degree in the three-phase circuit to be analyzed is calculated, and then a preliminary judgment is made as to whether there is a phase line fault in the three-phase circuit to be analyzed. If it is preliminarily judged that there is a faulty phase line in the three-phase circuit to be analyzed, the fault characteristic parameters of each phase line in the three-phase circuit to be analyzed are further extracted, and the possible fault coefficients of each phase line in the three-phase circuit to be analyzed are deeply analyzed, and finally the fault phase line in the three-phase circuit to be analyzed is determined, and finally the fault type and fault location point of the fault phase line in the three-phase circuit to be analyzed are analyzed, which effectively solves the problem that there are still defects and disadvantages in the current screening of fault lines in three-phase circuits, can effectively improve the reliability and safety of the power system, and has important practical value for the maintenance and management of the power system. At the same time, by timely discovering and handling faults, the system can maintain stable operation and avoid system collapse or fault chain effects caused by faults.

[0146] The above embodiments are only used to illustrate the technical method of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical method of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present application.

Claims

1. A fault line selection analysis method based on single-phase asymmetry, characterized in that: Step 1: Install current and voltage sensors in each phase line of the three-phase circuit to be analyzed to collect the current and voltage of each phase line at the target monitoring time point in real time; Step 2: Based on the current and voltage of each phase line at the target monitoring time point, calculate the imbalance degree in the three-phase circuit to be analyzed, and generate a preliminary detection result based on the imbalance degree; Step 3: When the preliminary detection result shows that there is a fault risk, the fault characteristic parameters of each phase line are extracted, based on which the fault possibility coefficient of each phase line is generated, and the fault phase line in the three-phase circuit to be analyzed is determined; Step 4: Analyze the fault phase line in the three-phase circuit to be analyzed, and obtain the fault type and fault location of the fault phase line in the three-phase circuit to be analyzed; Step 5: Send relevant information of the faulty phase line to the power grid control center or maintenance personnel; The fault characteristic parameters include voltage change rate, current mutation value and voltage harmonic amplitude; wherein the voltage change rate is obtained by the following steps: By installing a voltage sensor in each phase line corresponding to the three-phase circuit to be analyzed, the voltage value of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point is obtained; The voltage values ​​of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point are imported into the oscilloscope to obtain the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed corresponding to the real-time monitoring time point, and the time points of each peak corresponding to the real-time monitoring time point in the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed are screened out, and the difference calculation is performed, and the result of the difference calculation is averaged to obtain the peak time interval average value of the voltage waveform diagram of each phase line in the three-phase circuit to be analyzed , through the formula Calculate the voltage angular frequency of each phase line in the three-phase circuit to be analyzed ; Extract the voltage waveform of the A phase line in the three-phase circuit to be analyzed at the real-time monitoring time point from the voltage waveform of each phase line in the three-phase circuit to be analyzed at the real-time monitoring time point, and select the voltage value at t=0 as the reference voltage value, where t represents the number of each real-time monitoring time point; Import reference voltage value into known waveform equation In the example, at t=0: ,in, Indicates the peak voltage values ​​of the A phase line in the three-phase circuit to be analyzed at the corresponding real-time monitoring time point, i represents the number of each peak, i=1, 2, ..., m; m is the total number of peaks; is the voltage angular frequency of phase A in the three-phase circuit to be analyzed; is the voltage phase angle of phase A in the three-phase circuit to be analyzed; Will and The two equations are combined to obtain the voltage phase angle of phase A in the three-phase circuit to be analyzed. ; By formula Calculate the voltage phase angle of phase B in the three-phase circuit to be analyzed; Calculate and obtain the voltage phase angle of the C phase line in the three-phase circuit to be analyzed; The maximum voltage value corresponding to each phase line in the three-phase circuit to be analyzed is selected from the voltage values ​​corresponding to each real-time monitoring time point of each phase line in the three-phase circuit to be analyzed. , obtain the mathematical model of the instantaneous voltage of each phase line in the three-phase circuit to be analyzed corresponding to each real-time monitoring time point; the mathematical model is , and derive it , get the voltage change rate of each phase line in the three-phase circuit to be analyzed ; The current mutation value and voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed are obtained by the following steps: Step 1: Obtain the current of each phase line in the three-phase circuit to be analyzed at the target monitoring time point and voltage ; Through the conversion formula Convert the current of each phase line into the corresponding phase current ; Through the conversion formula Convert the voltage of each phase line into the corresponding phase voltage ; By formula Calculate the coil inductance value of each phase line in the three-phase circuit to be analyzed at the target monitoring time point. represents the circuit frequency of the hth phase line in the predefined three-phase circuit to be analyzed; By formula Calculate and obtain the sudden change value of the current of each phase line in the three-phase circuit to be analyzed; Step 2: Extract the voltage signal value of each harmonic of the voltage waveform corresponding to each phase line in the three-phase circuit to be analyzed from the voltage waveform corresponding to the real-time monitoring time point of each phase line in the three-phase circuit to be analyzed And the period to which each harmonic corresponds to the voltage signal value , n represents the number of each harmonic, which is obtained by integration: ,in, It is represented as the real-time monitoring time point of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed. They respectively represent the cosine and sine functions of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed; By calculation , get the amplitude of the nth harmonic of the voltage waveform corresponding to the hth phase line in the three-phase circuit to be analyzed , and sum and average the harmonic quantities to obtain the voltage harmonic amplitude of each phase line in the three-phase circuit to be analyzed; Generating the fault possibility coefficient of each phase line based on the fault characteristic parameters of each phase line includes: Get the voltage change rate of each phase line in the three-phase circuit to be analyzed , Current mutation value And the voltage harmonic amplitude ; Comprehensive analysis obtains the possible fault coefficient of each phase line in the three-phase circuit to be analyzed , where c1, c2 and c3 represent the weight factors of the predefined voltage change rate, current mutation value and voltage harmonic amplitude corresponding to the possible fault coefficient, respectively. , and They represent the pre-planned allowable voltage change rate difference, allowable current mutation difference and allowable voltage harmonic change difference respectively. , and They respectively represent the voltage change rate threshold, current mutation threshold and voltage harmonic change threshold of the hth phase line in the three-phase circuit to be analyzed stored in the database; The fault type of the fault phase line in the three-phase circuit to be analyzed is obtained by analysis, including: By breaking down the formula , decompose to obtain the negative sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ,in, Indicates the plural unit, ; e is a natural constant, j represents an imaginary unit, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point; By breaking down the formula , decompose to obtain the positive sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ; By formula Get the zero-sequence current component of the three-phase circuit to be analyzed corresponding to the target monitoring time point ; Obtain the current at each monitoring time point before the target monitoring time point corresponding to the three-phase circuit to be analyzed, and calculate the negative-sequence current component, positive-sequence current component and zero-sequence current component at each monitoring time point before the target monitoring time point, sort them with the negative-sequence current component, positive-sequence current component and zero-sequence current component at the target monitoring time point corresponding to the three-phase circuit to be analyzed, and integrate them to obtain the negative-sequence current component set, positive-sequence current component set and zero-sequence current component set at the monitoring time point corresponding to the three-phase circuit to be analyzed; Extract the negative sequence current component from the negative sequence current component set , s represents the number of each monitoring time point, s=1, 2, …, y, y is the total number of negative sequence current components in the negative sequence current component set; through the formula The analysis results show that the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponds to each monitoring time point ;in are the negative sequence current components of the three-phase circuit to be analyzed corresponding to the s+1th and s-1th monitoring time points respectively; According to the calculation method of the negative sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point, the positive sequence current component variation coefficient and the zero sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to each monitoring time point are calculated in the same way; If the zero-sequence current component variation coefficient corresponding to any monitoring time point of the three-phase circuit to be analyzed is greater than the current component variation reference coefficient, and the corresponding positive-sequence current component variation coefficient and negative-sequence current component variation coefficient are both less than the current component variation reference coefficient; then the fault type is determined to be a single-phase grounding fault; If the positive-sequence current component variation coefficient of the three-phase circuit to be analyzed corresponding to any monitoring time point is greater than the current component variation reference coefficient, and the corresponding zero-sequence current component variation coefficient and negative-sequence current component variation coefficient are both less than the current component variation reference coefficient; then the fault type is determined to be a three-phase short-circuit fault; If the negative-sequence current component variation coefficient corresponding to any monitoring time point of the three-phase circuit to be analyzed is greater than the current component variation reference coefficient, and the corresponding zero-sequence current component variation coefficient is less than the current component variation reference coefficient, the fault type is determined to be a two-phase grounding fault; If the zero-sequence current component variation coefficient and the negative-sequence current component variation coefficient corresponding to any monitoring time point of the three-phase circuit to be analyzed are both greater than the current component variation reference coefficient, the fault type is determined to be a two-phase to ground short-circuit fault; Analyzing the fault position point of the fault phase line in the three-phase circuit to be analyzed includes: Obtaining the fault time point of the fault phase line in the three-phase circuit to be analyzed, and the voltage and current at the line start point and line end point corresponding to the fault time point; the fault time point is the monitoring time point corresponding to the fault phase line; Obtain a virtual model diagram of a fault phase line in a three-phase circuit to be analyzed; Assume that the actual distance of the fault location point from the starting point of the fault phase line is x; By solving the equation , get the actual distance x of the fault location; in They represent the voltage and current at the starting point of the line at the time of the fault corresponding to the fault in the three-phase circuit to be analyzed. They represent the voltage and current at the end of the line at the time point corresponding to the fault of the fault phase line in the three-phase circuit to be analyzed, and Z represents the impedance per unit length of the circuit; The position of the fault location point is imported into the virtual model diagram of the fault phase line in the three-phase circuit to be analyzed, thereby obtaining the fault location point of the fault phase line in the three-phase circuit to be analyzed.

2. A fault line selection analysis method based on single-phase asymmetry according to claim 1, characterized in that: Calculating the imbalance degree in the three-phase circuit to be analyzed based on the current and voltage of each phase line at the target monitoring time point, including: Obtain the current and voltage of each phase line in the three-phase circuit to be analyzed at the target monitoring time point, and mark them as as well as , h represents the number of each phase line, and the specific value of h is a, b, c; By analyzing the formula , the average phase voltage in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the voltage unbalance rate VUR in the three-phase circuit to be analyzed is obtained by analysis, where: , and Respectively represent the voltages of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point; By analyzing the formula , the average phase current in the three-phase circuit to be analyzed is obtained by analysis , through the formula , the current unbalance rate CUR in the three-phase circuit to be analyzed is obtained by analysis, , and They respectively represent the currents of the A-phase line, the B-phase line, and the C-phase line in the three-phase circuit to be analyzed at the target monitoring time point; By formula The unbalance degree UI in the three-phase circuit to be analyzed is calculated.

3. A fault line selection analysis method based on single-phase asymmetry according to claim 2, characterized in that: The generating of a preliminary detection result based on the imbalance degree includes: Obtain the imbalance UI in the three-phase circuit to be analyzed; determine whether the imbalance UI is greater than the three-phase circuit imbalance threshold; if yes, set the preliminary detection result as having a fault risk; if no, set the preliminary detection result as having no fault risk; wherein the preliminary detection result includes a fault risk and a no fault risk.

4. The fault line selection analysis method based on single-phase asymmetry according to claim 1 is characterized in that: Determine the fault phase line in the three-phase circuit to be analyzed, and the specific determination operation is: The fault possibility coefficient of each phase line in the three-phase circuit to be analyzed is compared with the predefined phase line fault reference coefficient. If there is a phase line in the three-phase circuit to be analyzed whose fault possibility coefficient is greater than the predefined phase line fault reference coefficient, the phase line is marked as a faulty phase line, thereby determining the faulty phase line in the three-phase circuit to be analyzed.

5. A fault line selection and analysis device based on single-phase asymmetry, characterized in that: It is implemented based on a single-phase asymmetry-based fault line selection analysis method as described in any one of claims 1 to 4, and includes an electronic device and a computer-readable storage medium; The electronic device comprises a processor, a memory and a communication bus, wherein the memory stores a computer-readable program executable by the processor; The communication bus realizes the connection and communication between the processor and the memory; The processor is used to execute the computer readable program; The computer-readable storage medium stores one or more programs that can be executed by one or more processors.

Images