A method, medium and terminal for analyzing line error of transformer in high voltage substation

Abstract

The present invention is applicable to the field of line detection technology, and relates to a method, medium and terminal for analyzing line errors of transformers in high-voltage substations, including the following steps: S10, collecting N groups of three-phase voltage transformer secondary side signals; S20, determining the inter-group deviation of any two groups of three-phase signals; S30, determining the correlation coefficient of any two groups of three-phase signals; S40, determining the unbalance deviation of any two groups of three-phase signals; S50, determining the similarity of any two groups of three-phase signals; S60, grouping the signals according to the similarity of the three-phase signals; S70, performing error analysis on the same group of three-phase transformers. The present invention realizes online real-time monitoring of the error characteristics of capacitive voltage transformers, improves maintenance efficiency, and avoids the impact of power outage maintenance on power grid operation.

Description

Technical Field

[0001] The invention belongs to the technical field of line detection, and in particular relates to a method, a medium and a terminal for analyzing line errors of a transformer in a high-voltage substation. Background Art

[0002] Capacitor Voltage Transformer (CVT) is widely used in high-voltage application scenarios due to its good insulation properties. Compared with traditional electromagnetic voltage transformers, capacitor voltage transformers have a more complex structure and are more prone to out-of-tolerance phenomena during operation, thus affecting the fairness of electricity settlement trade. According to the national metrology verification regulations, the existing verification method is power-off offline verification. The same voltage signal is applied to the transformer to be verified and the high-precision standard at the same time. The difference between the output value of the transformer to be verified and the output value of the standard is the static error of the transformer. This method cannot reflect the dynamic change process of the transformer error under actual working conditions in real time, and it is difficult to shut down and repair high-voltage transmission and transformation lines. In addition, this maintenance method does not fully consider the health status of each transformer, and the maintenance efficiency is low.

[0003] The existing transformer error analysis method is based on the correlation of the transformer cluster. During the calculation process, using the signal on the same bus as the calculation unit for error calculation can effectively ensure the calculation accuracy of the algorithm. During the operation of the substation, the line switch will be switched according to the line load. At this time, if the line topology cannot be identified in time, the transformer error calculation model will not match the actual physical topology, resulting in inaccurate calculation. The patent with publication number CN104155627A provides an error characteristic detection method for a UHV capacitor voltage transformer, including step 1: performing an on-site handover detection of the electromagnetic voltage transformer in an offline state, and correcting the electromagnetic voltage transformer according to the detection result; step 2: using the corrected electromagnetic voltage transformer as a standard voltage transformer, and using an error online detection device to perform error detection on the capacitor voltage transformer in an online state; the capacitor voltage transformer is respectively connected to the transformer outgoing line and the high-voltage reactor outgoing line of the three-phase bus; the electromagnetic voltage transformer is connected to the bus between the transformer and the high-voltage reactor. This patent also uses a calibrated electromagnetic voltage transformer as a standard voltage transformer, and then compares it with the capacitive voltage transformer to be tested, and finally obtains the error result. This solution is also unable to detect the transformer error under the implementation conditions, and the detection efficiency is low.

[0004] Therefore, how to provide a method with high monitoring efficiency and capable of real-time dynamic monitoring of line topology to ensure the accuracy of error analysis is an urgent problem to be solved by personnel in this technical field. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for analyzing the line error of a high-voltage substation transformer, so as to solve the problems in the prior art of being unable to monitor the line topology in real time, low error analysis accuracy and low detection efficiency; in addition, the present invention also provides a medium and terminal for analyzing the line error of a high-voltage substation transformer.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for analyzing a transformer line error in a high-voltage substation, comprising the following steps:

[0008] S10, collecting N groups of three-phase voltage transformer secondary side signals;

[0009] S20, determining the inter-group deviation of any two groups of three-phase signals;

[0010] S30, determining the correlation coefficient of any two groups of three-phase signals;

[0011] S40, determining the unbalance deviation between any two groups of three-phase signals;

[0012] S50, determining the similarity between any two groups of three-phase signals;

[0013] S60, grouping the signals according to the similarity of the three-phase signals;

[0014] S70, performing error analysis on the same group of three-phase mutual inductors.

[0015] Furthermore, in step S10, assuming that any two groups of three-phase inductors are i and j respectively, their secondary side sampling data are and .

[0016] Furthermore, in step S20, the actual conversion relationship between the primary voltage and the secondary voltage of the transformer is:

[0017] ;

[0018] in, , They are the measured values ​​of the primary and secondary voltages of the voltage transformer, is the rated transformation ratio of the voltage transformer, is the error of the voltage transformer.

[0019] Furthermore, let the two channels be and , then:

[0020] ;

[0021] ;

[0022] in, , for The secondary voltage measurement value and the primary voltage measurement value of the transformer, For transformer The corresponding error is , For transformer The secondary side voltage measurement value and the primary side voltage measurement value, For transformer The corresponding error;

[0023] Then we have:

[0024] ;

[0025] Similarly, there are:

[0026] ;

[0027] ;

[0028] Let the inter-group deviation of the two groups of three-phase signals be:

[0029] ;

[0030] .

[0031] Furthermore, in step S30, the two channels are set to and , then:

[0032] ;

[0033] in, for , The covariance of , for , The standard deviation of

[0034] Similarly, there are:

[0035] ;

[0036] ;

[0037] Let the correlation coefficient of the two sets of three-phase signals be:

[0038] .

[0039] Furthermore, the specific steps of step S40 are as follows:

[0040] S401, three-phase voltage unbalance deviation formula is as follows:

[0041] ;

[0042] ;

[0043] in:

[0044] ;

[0045] ;

[0046] ;

[0047] in, is the three-phase voltage zero-sequence unbalance, is the three-phase voltage negative sequence unbalance, Respectively represent the zero sequence, positive sequence and negative sequence of the three-phase voltage;

[0048] S402. For the two groups of three-phase signals i and j, the unbalance deviation is:

[0049] .

[0050] Furthermore, the similarity in step S50 is:

[0051] ;

[0052] That is, the vector [ ] model.

[0053] Furthermore, the specific steps of step S60 are as follows:

[0054] S601. For N groups of three-phase voltage transformers, traverse any two groups of three-phase voltage transformers. ( ), calculate the similarity of its three-phase signals ;

[0055] S602: For two groups of three-phase voltage transformers, when their signal similarity is less than a threshold, it is determined that the two groups of three-phase signals come from the same bus. The threshold is ;

[0056] S603: group N groups of three-phase signals according to the similarity of the three-phase signals, connect all three-phase signals in the group to the same bus, and perform error calculation.

[0057] In a second aspect, the present invention further provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0058] In a third aspect, the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method as described above.

[0059] Compared with the prior art, the method, medium and terminal for analyzing the line error of a transformer in a high-voltage substation provided by the present invention have at least the following beneficial effects:

[0060] The existing technology cannot monitor the line topology in real time, resulting in low error analysis accuracy and low detection efficiency. The present invention has a simple process and convenient operation. By analyzing the secondary side data of the voltage transformer in real time and analyzing the similarity of two groups of three-phase signals, the line topology is dynamically monitored in real time to ensure that the three-phase signals in the calculation unit are connected to the same bus. When the substation line topology changes, the algorithm can adaptively identify the switching of the line switch, thereby adjusting the transformer error calculation program, thereby ensuring the accuracy and reliability of the error analysis method. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the scheme of the present invention, a brief introduction is given below to the figures required for use in the description of the embodiments. Obviously, the figures described below are some embodiments of the present invention. For ordinary technicians in this field, other figures can be obtained based on these figures without paying any creative work.

[0062] Figure 1 A flow chart of a method for analyzing a transformer line error in a high-voltage substation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0065] The present invention provides a method for analyzing a transformer line error in a high-voltage substation, which is applied to an error analysis process of a capacitive voltage transformer in a high-voltage application scenario. The method for analyzing a transformer line error in a high-voltage substation comprises the following steps:

[0066] S10, collecting N groups of three-phase voltage transformer secondary side signals;

[0067] S20, determining the inter-group deviation of any two groups of three-phase signals;

[0068] S30, determining the correlation coefficient of any two groups of three-phase signals;

[0069] S40, determining the unbalance deviation between any two groups of three-phase signals;

[0070] S50, determining the similarity between any two groups of three-phase signals;

[0071] S60, grouping the signals according to the similarity of the three-phase signals;

[0072] S70, performing error analysis on the same group of three-phase mutual inductors.

[0073] The present invention realizes online real-time monitoring of error characteristics of a capacitor voltage transformer, improves maintenance efficiency, and avoids the impact of power-off maintenance on power grid operation.

[0074] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0075] The present invention provides a method for analyzing the line error of a high-voltage substation transformer, which is applied to the error analysis process of a capacitive voltage transformer in a high-voltage application scenario. Figure 1 As shown, in this embodiment, the method for analyzing the line error of a transformer in a high-voltage substation includes the following steps:

[0076] S10, collecting N groups of three-phase voltage transformer secondary side signals, and determining whether the two groups of three-phase signals are connected to the same bus by analyzing the similarity of the two groups of three-phase signals;

[0077] Specifically, in this embodiment, by arbitrarily selecting i , j two groups of three-phase inductors are used as examples to illustrate, assuming that the secondary side sampling data is and .

[0078] S20, calculating the inter-group deviation of two groups of three-phase signals;

[0079] Specifically, in this embodiment, the actual conversion relationship between the primary voltage and the secondary voltage of the transformer is:

[0080] ;

[0081] in, , They are the measured values ​​of the primary and secondary voltages of the voltage transformer, is the rated transformation ratio of the voltage transformer, is the error of the voltage transformer.

[0082] Further, in this embodiment, , Taking two channels as an example, we have:

[0083] ;

[0084] ;

[0085] in, , For transformer The secondary side voltage measurement value and the primary side voltage measurement value, For transformer The corresponding error is , For transformer The secondary side voltage measurement value and the primary side voltage measurement value, For transformer The corresponding error. Since the primary voltage value of the power grid is relatively stable, that is, the transformer , The corresponding primary voltage and Equal, divide the two equations to get:

[0086] ;

[0087] in, is the error of the transformer, which is a small number close to 0. It can be obtained from Taylor's formula:

[0088] ;

[0089] Then we have:

[0090] ;

[0091] ;

[0092] Ignoring the small quantity of order 2, we have:

[0093] ;

[0094] Similarly, there are:

[0095] ;

[0096] ;

[0097] Let the inter-group deviation of the two groups of three-phase signals be:

[0098] ;

[0099] .

[0100] S30, calculating the correlation coefficient of two groups of three-phase signals;

[0101] Specifically, in this embodiment, the correlation coefficients of the two channels with the same phase of the two groups of three-phase signals are calculated. , Taking two channels as an example, we have:

[0102] ;

[0103] in, for , The covariance of , for , The standard deviation of .

[0104] Similarly, there are:

[0105] ;

[0106] ;

[0107] Let the correlation coefficient of the two sets of three-phase signals be:

[0108] .

[0109] S40, calculating the unbalance deviation of two groups of three-phase signals;

[0110] Specifically, in this embodiment, the specific steps of step S40 are as follows:

[0111] S401, the calculation method of three-phase voltage unbalance is as follows:

[0112] ;

[0113] ;

[0114] in,

[0115] ;

[0116] ;

[0117] ;

[0118] in, is the three-phase voltage zero-sequence unbalance, is the three-phase voltage negative sequence unbalance, Respectively represent the zero sequence, positive sequence and negative sequence of the three-phase voltage;

[0119] S402. For the two groups of three-phase signals i and j, their unbalanced deviation is:

[0120] .

[0121] S50, calculating the similarity of two groups of three-phase signals:

[0122] ;

[0123] That is, the vector [ ] model.

[0124] S60, grouping the signals according to the similarity of the three-phase signals;

[0125] Specifically, in this embodiment, the specific steps of step S60 are as follows:

[0126] S601. For N groups of three-phase voltage transformers, traverse any two groups of three-phase voltage transformers. ( ), calculate the similarity of its three-phase signals ;

[0127] S602: For two groups of three-phase inductors, when their signal similarity is less than a threshold, it can be considered that the two groups of three-phase signals come from the same bus. The threshold is selected based on experience. ;

[0128] S603: N groups of three-phase signals are grouped according to the similarity of the three-phase signals. All three-phase signals in the group are connected to the same bus and used as a calculation unit for error calculation.

[0129] S70, performing error analysis on the same group of three-phase mutual inductors.

[0130] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, any one of the methods in the present embodiment is implemented.

[0131] An embodiment of the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes any one of the methods in this embodiment.

[0132] The computer-readable storage medium in this embodiment can be understood by ordinary technicians in this field: all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to the computer program. The aforementioned computer program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

[0133] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication with each other. The memory is used to store computer programs, the communication interface is used to communicate, and the processor and the transceiver are used to run computer programs so that the electronic terminal executes each step of the above method.

[0134] The method, medium and terminal for analyzing the line error of the transformer in the high-voltage substation described in the above embodiment cannot monitor the line topology in real time in the prior art, resulting in low accuracy of error analysis and low detection efficiency. The present invention has a simple process and convenient operation. By analyzing the secondary side data of the voltage transformer in real time and analyzing the similarity of two groups of three-phase signals, the line topology is dynamically monitored in real time to ensure that the three-phase signals in the calculation unit are connected to the same bus. When the substation line topology changes, the algorithm can adaptively identify the switching of the line switch, thereby adjusting the transformer error calculation program, thereby ensuring the accuracy and reliability of the error analysis method.

[0135] Obviously, the embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A method for analyzing a transformer line error in a high-voltage substation, characterized in that: The following steps are involved: S10, collecting N groups of three-phase voltage transformer secondary side signals; In step S10, assume that any two groups of three-phase inductors are respectively i and j, and their secondary side sampling data is A i，2 , B i，2 , C i，2 and A j，2 , B j，2 , C j，2 ; S20, determining the inter-group deviation of any two groups of three-phase signals; In step S20, the actual conversion relationship between the primary voltage and the secondary voltage of the transformer is: Among them, U1 and U2 are the measured values ​​of the primary and secondary voltages of the voltage transformer respectively, and k r is the rated transformation ratio of the voltage transformer, ε is the error of the voltage transformer; Assume that the two channels are A i and A j , then: Among them, A i，2 , A i，1 A i The secondary voltage measurement value and the primary voltage measurement value of the transformer, ε A，i For transformer A i The corresponding error, where A j，2 , A j，1 For transformer A j The secondary side voltage measurement value and the primary side voltage measurement value, ε A，j For transformer A j The corresponding error; Then we have: Similarly, there are: Let the inter-group deviation of the two groups of three-phase signals be: DevB i，j =[e A，i -e A，j ,he B，i -e B，j ,he C，i -e C，j ] S30, determining the correlation coefficient of any two groups of three-phase signals; In step S30, the two channels are set to A. i and A j , then: Among them, Cov(A i，2 , A j，2 ) is A i，2 , A j，2 The covariance of A i，2 , A j，2 The standard deviation of ; similarly: Let the correlation coefficient of the two sets of three-phase signals be: DevR i，j =[r(A i ,A j ),r(B i ,B j ),r(C i ,C j )]; S40, determining the unbalance deviation between any two groups of three-phase signals; The specific steps of step S40 are as follows: S401, three-phase voltage unbalance deviation formula is as follows: in: in, is the three-phase voltage zero-sequence unbalance, is the negative sequence unbalance of the three-phase voltage, U0, U1, and U2 represent the zero sequence, positive sequence, and negative sequence of the three-phase voltage respectively; S402. For the two groups of three-phase signals i and j, the unbalance deviation is: S50, determining the similarity between any two groups of three-phase signals; The similarity in step S50 is: F(i,j)=|DevB i，j ,DevR i，j ,DevU i，j | That is, vector [DevB i，j , DevR i，j , DevU i，j ]; S60, grouping the signals according to the similarity of the three-phase signals; The specific steps of step S60 are as follows: S601. For N groups of three-phase voltage transformers, traverse any two groups of three-phase voltage transformers m, n (m, n = 1, 2, 3 ... N, and m ≠ n), and calculate their three-phase signal similarity F (m, n); S602, for two groups of three-phase voltage transformers, when their signal similarity is less than a threshold, it is determined that the two groups of three-phase signals come from the same bus, and the threshold is λ=0.02%; S603, grouping N groups of three-phase signals according to the similarity of the three-phase signals, connecting all three-phase signals in the group to the same bus, and performing error calculation; S70, performing error analysis on the same group of three-phase mutual inductors.

2. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to claim 1 is implemented.

3. An electronic terminal, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method as claimed in claim 1.

Images