Method for evaluating secondary errors of multiple voltage transformers in double-bus connection mode
阅读说明：本技术 双母线接线形式下多台电压互感器继发性误差的评估方法 (Method for evaluating secondary errors of multiple voltage transformers in double-bus connection mode ) 是由 窦峭奇 于 2020-09-04 设计创作，主要内容包括：本发明提供一种双母线接线形式下多台电压互感器继发性误差超差的自适应评估方法和系统。本发明基于三相电压平衡柔性约束条件将站内电压互感器划分为多个评估群体,建立初始评估模态以判断是否存在运行异常的互感器,完成复杂运行工况下单台互感器的状态评估与定位；当存在异常时,在不停电检修的前提下基于自适应切换方法将评估模态从初始模态切换到异常模态,并根据待评估群体中柔性约束条件的变化,建立新的评估子模态,完成站内剩余电压互感器继发性运行误差异常的有效评估。本发明能在不停电运行的条件下,实时实现复杂工况下站内单台和多台电压互感器继发性误差超差的自适应评估分析,评估方法具有普适性和易实现性。(The invention provides a self-adaptive evaluation method and a self-adaptive evaluation system for secondary error out-of-tolerance of multiple voltage transformers in a double-bus connection mode. According to the method, the voltage transformers in the station are divided into a plurality of evaluation groups based on three-phase voltage balance flexible constraint conditions, an initial evaluation mode is established to judge whether a transformer with abnormal operation exists or not, and the state evaluation and positioning of a single transformer under a complex operation condition are completed; when the abnormal state exists, the evaluation mode is switched from the initial mode to the abnormal mode based on a self-adaptive switching method on the premise of maintenance without power outage, a new evaluation sub-mode is established according to the change of the flexible constraint conditions in the group to be evaluated, and effective evaluation of the secondary operation error abnormality of the residual voltage transformer in the station is completed. The method can realize the self-adaptive evaluation and analysis of the secondary error out-of-tolerance of the single and multiple voltage transformers in the station under the complex working condition in real time under the condition of uninterrupted operation, and has universality and easy realizability.)
1. A method for evaluating secondary errors of a plurality of voltage transformers in a double-bus connection mode is characterized by comprising the following steps:
collecting secondary output signals of total-station voltage transformer during actual operationSaid output signalThe method comprises the steps of respectively carrying out standardization processing on normal operation data and real-time sampling data to obtain a data matrix
Establishing a SPE calculation model in a double-bus connection mode;
modeling the data set
The sampling data set
when a voltage transformer with abnormal operation errors is judged to appear in the voltage transformers to be detected, positioning the voltage transformer with abnormal operation errors according to the contribution rate of each voltage transformer to the real-time SPE statistic;
based on the position information of the voltage transformer with the abnormal operation error, data are extracted again to construct a modeling data set of an abnormal mode
Re-decimating data to construct a sample data set of the real-time sample data
2. The method of claim 1, wherein the normalization process results in the data matrixThe process comprises the following steps:
step 101, generating a sample matrix from the secondary output signals，，；
n is the number of voltage transformers, and m is the number of sampling points;
step 102, carrying out standardization processing on the sample matrix to obtain a data matrix:
；
wherein the content of the first and second substances,
3. The method of claim 1, wherein the establishing of the SPE calculation model in the form of double bus connections, the calculating of the statistical quantity control limit and the real-time SPE statistics comprises:
step 201 of computing whitening from said modeled or sampled data setMatrix array
Step 202, whitening the matrix according to the whitening matrixCalculating to obtain an orthogonal matrix(ii) a m is the number of sampling points;
step 203, according to the orthogonal matrix
Step 204, the unmixing matrix is processed
step 205, determining SPE statistic calculation function according to the observation data and the reconstruction variable, and calculating confidence coefficient according to the calculation function
4. The method according to claim 3, wherein the step 201 comprises:
step 20101, covariance matrix of the modeling dataset or sampling datasetObtaining a diagonal matrix by eigenvalue decompositionSum matrix
step 20102, calculating the whitening matrix:
。
5. The method of claim 3, wherein the step 202 comprises:
step 20201, determining the number of independent components to be estimated, and recording i = 1;
20202, randomly selecting an initial unit vector
In a step 20203, the process is carried out,
step 20204, for
step 20205, judge
step 20206, mixing all
6. The method according to claim 3, wherein in step 204, the unmixing matrix is applied to the unmixing matrix
will be provided withRearranging according to the order from big to small, and calculating the order characteristic quantityWherein, in the step (A),
calculating the contribution rate of each row vectorAnd cumulative contribution rate：
Dividing the main components according to whether the cumulative contribution rate reaches 85%And residual components；
Calculating a reconstruction variable of a main component at the t-th sampling moment:
；
7. The method according to claim 6, wherein in step 205The statistical quantity is calculated as:
；
calculating confidence using a kernel density estimation methodLower statistical quantity control limitThe method comprises the following steps:
step 20501, orderThe statistical probability density function is
in the formula (I), the compound is shown in the specification,
step 20502, estimating by kernel density estimationProbability distribution function of statistics：
Step 20503, calculate at significance levelStatistical control limits of:
typical values of (a) range from 95% to 99%.
8. The method of claim 1, wherein calculating a contribution rate of each phase voltage transformer to the real-time SPE statistics comprises:
；
wherein the content of the first and second substances,
and positioning the single voltage transformer with the abnormal operation error according to the contribution rate, and reporting early warning information.
9. A system for evaluating secondary errors of a plurality of voltage transformers in a double-bus connection mode is characterized by comprising:
the data acquisition and preprocessing module is used for acquiring secondary output signals of the total-station voltage transformer during actual operation
The calculation model module is used for establishing a SPE calculation model in a double-bus connection mode;
an evaluation module for evaluating the modeling datasetInputting the calculation model, and calculating to obtain confidence
the abnormal state switching module is used for positioning the voltage transformers with abnormal operation errors according to the contribution rate of each voltage transformer to the real-time SPE statistic when the voltage transformers with abnormal operation errors are judged to appear in the voltage transformers to be detected; based on the position information of the voltage transformer with the abnormal operation error, data are extracted again to construct a modeling data set of an abnormal mode
10. A non-transitory computer-readable storage medium, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method for evaluating secondary errors of a plurality of voltage transformers in a double busbar configuration according to any one of claims 1 to 8.
Technical Field
The invention relates to the field of power distribution equipment state evaluation and fault diagnosis, in particular to an evaluation method for secondary errors of multiple voltage transformers in a double-bus connection mode.
Background
The 220kV transformer substation and the large and medium power plant are widely applied to double-bus wiring, the wiring mode has the advantages that the maintenance is convenient and simple, one bus can be maintained under the condition that the normal operation of the other bus is not interfered by the operation of switching the buses, and the wiring mode is flexible in scheduling and convenient to expand.
Under the double-bus connection mode, the existing mature offline detection method solves the problem of abnormal detection of the operation error of the voltage transformer, but the offline detection method can be completed only when power is cut off and the operation error of the voltage transformer cannot be evaluated in real time; at present, various online detection methods exist, but the online detection method is a single-mode evaluation method for isolated problems, the evaluation group division mode and the constraint condition are single, the evaluation group cannot be flexibly divided according to a plurality of physical topological relations among voltage transformers and the change characteristics of the operation errors of the voltage transformers, and the possibility that the operation errors of the remaining voltage transformers in the station are continuously abnormal after the operation errors of the single voltage transformer are abnormal is not considered. For a transformer substation widely applied in a double-bus connection mode, in order to ensure power supply reliability in engineering practice, the power failure chance of the transformer substation is few and the time is short, so that even if a situation that a single abnormal voltage transformer cannot be replaced in time is diagnosed, namely, the possibility that the remaining voltage transformers in the substation are continuously abnormal exists, and an effective evaluation method for the secondary operation error abnormal state of the multiple voltage transformers in the double-bus connection transformer substation does not exist.
Therefore, a self-adaptive evaluation method for secondary error over-tolerance of multiple voltage transformers in a double-bus connection mode needs to be established to solve the problem of secondary operation error abnormity of the voltage transformers.
Disclosure of Invention
The existing voltage transformer evaluation method is a single-mode evaluation method only aiming at isolated problems, the division and constraint conditions of the overall evaluation group are single, and the evaluation group cannot be flexibly divided according to a plurality of physical topological relations among voltage transformers and the change characteristics of operation errors, so that the existing voltage transformer evaluation method can only be applied to the preset working condition of a specific group, and the existing evaluation method cannot be applied to complex multi-mode evaluation problems such as common complex operation working conditions of primary voltage regulation, asymmetric load and the like and secondary operation error abnormity of a plurality of voltage transformers in a double-bus wiring type transformer substation.
In order to solve the defect that the conventional evaluation method is applied to a double-bus wiring type transformer substation, the invention provides an evaluation method and system for secondary errors of a plurality of voltage transformers in a double-bus wiring type.
The technical scheme for solving the problem of operation error evaluation of a single voltage transformer and a plurality of voltage transformers in a double-bus wiring type transformer substation under complex working conditions is as follows:
in a first aspect, the invention provides a method for evaluating secondary errors of multiple voltage transformers in a double-bus connection mode, which comprises the following steps:
collecting secondary output signals of total-station voltage transformer during actual operationSaid output signalThe method comprises the steps of respectively carrying out standardization processing on normal operation data and real-time sampling data to obtain a data matrix
Establishing a SPE calculation model in a double-bus connection mode;
modeling the data setInputting the calculation model, and calculating to obtain confidence
The sampling data set
when a voltage transformer with abnormal operation errors is judged to appear in the voltage transformers to be detected, positioning the voltage transformer with abnormal operation errors according to the contribution rate of each voltage transformer to the real-time SPE statistic;
based on the position information of the voltage transformer with the abnormal operation error, data are extracted again to construct a modeling data set of an abnormal modeThe modeling data set isInputting the calculation model, and calculating to obtain the confidence coefficient of the abnormal mode
Re-decimating data to construct a sample data set of the real-time sample data
In a second aspect, the present invention provides a system for detecting the state of a voltage transformer in a double-bus connection mode, comprising:
the data acquisition and preprocessing module is used for acquiring secondary output signals of the total-station voltage transformer during actual operationSaid output signal
The calculation model module is used for establishing a SPE calculation model in a double-bus connection mode;
an evaluation module for evaluating the modeling datasetInputting the calculation model, and calculating to obtain confidenceStatistical amount control limit of lower SPE
the abnormal state switching module is used for positioning the voltage transformers with abnormal operation errors according to the contribution rate of each voltage transformer to the real-time SPE statistic when the voltage transformers with abnormal operation errors are judged to appear in the voltage transformers to be detected; based on the position information of the voltage transformer with the abnormal operation error, data are extracted again to construct a modeling data set of an abnormal modeThe modeling data set is
In a third aspect, the present invention provides an electronic device comprising:
a memory for storing a computer software program;
and the processor is used for reading and executing the computer software program stored in the memory and realizing the self-adaptive evaluation method for the secondary error over-tolerance of the multiple voltage transformers in the double-bus connection mode.
In a fourth aspect, the present invention provides a non-transitory computer readable storage medium, wherein the storage medium stores therein a computer software program for implementing the method for adaptive evaluation of multiple voltage transformer secondary error out-of-tolerance in a dual bus connection mode according to the first aspect of the present invention.
The beneficial effect of adopting the further scheme is that: the detection and the positioning of the abnormal voltage transformer are realized only according to the operation data of the voltage transformer to be detected without using a standard voltage transformer on site, so that the evaluation cost is reduced, and the operation and maintenance level of the voltage transformer is improved; after the abnormal operation of one voltage transformer is judged, the mode can be switched on the basis of the positioning information of the voltage transformer with the abnormal operation, the data set is collected again to carry out the subsequent real-time operation error monitoring of the voltage transformer, the error state of the voltage transformer in the whole operation period can be tracked and accurately evaluated in real time, and the error state of the voltage transformer under a certain working condition and in a certain time period can be avoided being evaluated only in the field test; the method can solve the problem of evaluating the operation states of a single voltage transformer and a plurality of voltage transformers in the transformer substation under the complex working condition, namely, the remaining voltage transformers can still be evaluated under the condition of maintaining abnormal voltage transformers without power outage, and the effectiveness of the on-line evaluation method in long-term operation under the condition of power outage is kept.
Drawings
FIG. 1 is a flow chart of a preferred embodiment of a method for evaluating secondary errors of a plurality of voltage transformers in a double bus connection mode according to the present invention;
FIG. 2 is a diagram illustrating real-time data in an initial mode according to an embodiment of the present invention
FIG. 3 is a schematic diagram illustrating the contribution rate of a three-phase voltage transformer with abnormal operating errors in an initial mode according to an embodiment of the present disclosure;
FIG. 4 is a diagram of the real-time mode of abnormal neutron mode 1 in the embodiment of the present inventionA schematic of the statistics;
fig. 5 is a schematic diagram of the contribution ratio of the three-phase voltage transformer with abnormal operation error in the abnormal mode neutron mode 1 in the specific application embodiment provided by the present invention.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.
The embodiment of the invention provides an evaluation method for secondary errors of a plurality of voltage transformers in a double-bus connection mode, and aims to solve the problem of evaluation of operation errors of a single voltage transformer and a plurality of voltage transformers in a double-bus connection mode transformer substation under a complex working condition through a self-adaptive multi-mode systematization method under the conditions of not depending on standard voltage transformers and uninterrupted operation, and obtain the evaluation results of online operation error states of the single voltage transformer and the plurality of voltage transformers in the double-bus connection mode transformer substation. Specifically, the method comprises the following steps:
collecting secondary output signals of total-station voltage transformer during actual operation
And establishing a SPE calculation model in a double-bus connection mode.
Modeling data set
Sampling data set
If the real-time SPE statistic is not greater than the statistic control limitAnd when the situation shows that the voltage transformer to be detected is in a normal operation state, continuously monitoring and updating the real-time SPE statistic.
When a voltage transformer with abnormal operation errors is judged to appear in the voltage transformers to be detected, positioning the voltage transformer with abnormal operation errors according to the contribution rate of each voltage transformer to the real-time SPE statistic;
based on the position information of the voltage transformer with abnormal operation error, data are extracted again to construct a modeling data set of an abnormal mode
Data re-extraction to construct real-time sampled dataSample data setTo sample a data setCalculating real-time SPE statistic by the input calculation model, wherein the real-time SPE statistic is greater than the statistic control limit
The evaluation method for the secondary errors of the multiple voltage transformers in the double-bus connection mode, provided by the invention, does not need to use a standard voltage transformer on site, realizes the judgment of an abnormal voltage transformer only according to the operation data of the voltage transformer to be detected, reduces the evaluation cost, is favorable for improving the operation and maintenance level of the voltage transformer, can switch the modes and reacquire a data set to monitor the real-time operation errors of the subsequent voltage transformer on the basis of the positioning information of the voltage transformer with abnormal operation after judging that one voltage transformer has abnormal operation, has higher engineering application value for the complex evaluation problem of the self-adaptive evaluation of the secondary errors of the multiple voltage transformers in the double-bus connection mode, solves the long-term operation problem of the online evaluation method under the condition of no power outage, and greatly improves the effectiveness and the adaptability of the online evaluation method, the operation characteristics of the current transformer substation are better adapted.
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