Dynamic Evaluation Method for Short-Circuit Resistance Ability of Transformers Based on Whole-Life Operation Information

Abstract

The present invention discloses a dynamic evaluation method for the short-circuit resistance ability of transformers based on full-life operation information. The method includes obtaining various parameters during the operation of transformers of multiple different manufacturers, models, and operation times, classifying and statistically analyzing the transformers by manufacturer and model to respectively obtain various parameters during the operation of multiple transformers of the same manufacturer and model within the corresponding operation time; performing a correlation analysis based on the calculated reduction value of the current short-circuit resistance ability of the transformer and the changes in various parameters during the operation, and screening out relevant parameters; constructing an evaluation model for each manufacturer and model of transformer according to the parameters related to the current short-circuit resistance ability of the transformer screened out; obtaining various parameters related to the short-circuit resistance ability of the transformer and inputting them into the evaluation model of the corresponding manufacturer and model to obtain an evaluation result. The present invention greatly improves the evaluation accuracy and realizes the advantage of energy conservation on the premise of ensuring effective evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic evaluation of the short - circuit resistance ability of transformers, and particularly relates to a dynamic evaluation method for the short - circuit resistance ability of transformers based on full - life operation information. Background Art

[0002] Transformers are important equipment in the power system and play the role of voltage conversion. There are various indicators for reflecting the current operating state and reliability of transformers, and the short - circuit resistance ability is one of them. Currently, generally, the short - circuit resistance ability is evaluated before leaving the factory. During the actual operation of the transformer, the short - circuit resistance ability of the transformer will decrease due to many factors. The actual maximum short - circuit current amplitude of the transformer is less than the allowable maximum short - circuit current amplitude of the transformer, and the actual maximum short - circuit current time is less than the dynamic and thermal stability time limits of the national standard transformer, which are the basic conditions for ensuring the safe operation of the transformer. Therefore, it is very necessary to dynamically evaluate the short - circuit resistance ability of the transformer during its operation. Summary of the Invention

[0003] The purpose of the present invention is to provide a dynamic evaluation method for the short - circuit resistance ability of transformers based on full - life operation information in view of the deficiencies of the existing technology.

[0004] To achieve the above purpose, the present invention provides a dynamic evaluation method for the short - circuit resistance ability of transformers based on full - life operation information, including:

[0005] Obtain various parameters during the operation of transformers of multiple different manufacturers, models, and operation times, classify and statistically analyze the transformers by manufacturer and model to respectively obtain various parameters during the operation of multiple transformers of the same manufacturer and model within the corresponding operation time;

[0006] Calculate the reduction value of the current short - circuit resistance ability of the transformer, perform a correlation analysis based on the reduction value of the current short - circuit resistance ability of the transformer and the changes in various parameters during the operation period, and screen out the parameters related to the current short - circuit resistance ability of the transformer;

[0007] Construct an evaluation model for each manufacturer and model of transformer according to the parameters related to the current short - circuit resistance ability of the transformer screened out;

[0008] During the operation of the transformer, obtain various parameters related to the short - circuit resistance ability of the transformer and input them into the evaluation models of the corresponding manufacturers and models to obtain the evaluation results of the short - circuit resistance ability of the transformer.

[0009] Further, the calculation method of the reduction value of the current short - circuit resistance ability of the transformer is as follows:

[0010] δF = F O - F S

[0011] Among them, δF is the reduction value of the current short-circuit withstand ability of the transformer, and F O is the short-circuit withstand ability value of the transformer before leaving the factory, and F S is the current short-circuit withstand ability value of the transformer, and the F O and F S are calculated respectively through existing evaluation methods.

[0012] Furthermore, it further includes:

[0013] Set a correlation threshold, and screen out the parameters whose correlation coefficients are above the set correlation threshold.

[0014] Furthermore, the operating time is evenly distributed throughout the entire operating life of the transformer.

[0015] Furthermore, during the operation of the transformer, monitor the parameters related to the current short-circuit withstand ability of the transformer. When the change amount of the parameters related to the current short-circuit withstand ability of the transformer exceeds the set change threshold, trigger an evaluation.

[0016] Furthermore, set an evaluation interval time, and intermittently evaluate the short-circuit withstand ability of the transformer at the set evaluation interval time.

[0017] Beneficial effects: By collecting various parameters during the operation of transformers of multiple different manufacturers, models, and operating times, classifying and analyzing the transformers according to different manufacturers and models, and respectively constructing evaluation models, the evaluation accuracy is greatly improved; there are two ways to trigger the evaluation, namely parameter change and timing, achieving the advantage of energy saving on the premise of ensuring effective evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flowchart of a dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following further clarifies the present invention in conjunction with the accompanying drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0020] As Figure 1 shown, the embodiment of the present invention provides a dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information, including:

[0021] Obtain various parameters during the operation of transformers from multiple manufacturers, models, and operating times, classify and count the transformers by manufacturer and model, and respectively obtain various parameters during the operation of multiple transformers of the same manufacturer and model within the corresponding operating times. Specifically, the above-mentioned various parameters include operating voltage, current, types and frequencies of previous faults, magnitudes and durations of previous fault currents, commissioning time, etc. The above-mentioned operating times are evenly distributed throughout the entire operating life of the transformer to improve accuracy.

[0022] Calculate the reduction value of the current short-circuit withstand ability of the transformer. Specifically, the calculation method of the reduction value of the current short-circuit withstand ability of the transformer is as follows:

[0023] δF = F O - F S

[0024] where δF is the reduction value of the current short-circuit withstand ability of the transformer, and F O is the short-circuit withstand ability value of the transformer before leaving the factory, and F S is the current short-circuit withstand ability value of the transformer, and F O and F S are calculated respectively through existing evaluation methods. Conduct a correlation analysis based on the reduction value of the current short-circuit withstand ability of the transformer and the changes in various parameters during the operation period, and screen out the parameters related to the current short-circuit withstand ability of the transformer. The icon correlation analysis method can be used to conduct a correlation analysis on the reduction value of the current short-circuit withstand ability of the transformer and the changes in various parameters during the operation period. To reduce the amount of data, a correlation threshold can also be set, and the parameters with a correlation coefficient above the set correlation threshold are screened out. Thus, the parameter data with insufficient correlation is eliminated. Generally, the correlation threshold can be set to 0.2.

[0025] Construct an evaluation model for each manufacturer and model of transformer based on the parameters screened out as being related to the current short-circuit withstand ability of the transformer. Since the correlation direction of the same parameter for transformers of different manufacturers and models is generally the same, but the degree of correlation will vary, an evaluation model is constructed separately for transformers of different manufacturers and models, which can greatly improve the accuracy in the later evaluation stage.

[0026] During the operation of the transformer, obtain various parameters related to the short-circuit withstand ability of the transformer and input them into the evaluation models of the corresponding manufacturers and models to obtain the evaluation results of the short-circuit withstand ability of the transformer. Before evaluating the transformer, it is necessary to pre-select the manufacturer and model of the transformer, and during the later operation process, the corresponding evaluation model is automatically called for evaluation. After obtaining the evaluation results, if the short-circuit withstand ability of the transformer is lower than the set threshold, an alarm signal can be output to remind relevant personnel to conduct maintenance.

[0027] In the absence of emergencies, the short-circuit withstand capacity of the transformer decreases slowly with the aging of the equipment. Moreover, during the operation of the transformer, it is not necessary to evaluate the short-circuit withstand capacity of the transformer in real time. It is preferable to monitor the parameters related to the current short-circuit withstand capacity of the transformer. When the change amount of the parameters related to the current short-circuit withstand capacity of the transformer exceeds the set change threshold, an evaluation is triggered. An evaluation interval time can also be set, and the short-circuit withstand capacity of the transformer is intermittently evaluated at the set evaluation interval time.

[0028] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, the other parts not specifically described belong to the prior art or common general knowledge. Without departing from the principle of the present invention, several improvements and refinements can also be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information, characterized in that Including: Obtain various parameters during the operation of transformers of multiple different manufacturers, models, and operation times, classify and count the transformers by manufacturer and model to respectively obtain various parameters during the operation of multiple transformers of the same manufacturer and model within the corresponding operation time; Calculate the reduction value of the current short-circuit withstand capacity of the transformer, perform a correlation analysis based on the reduction value of the current short-circuit withstand capacity of the transformer and the changes in various parameters during the operation period, and screen out the parameters related to the current short-circuit withstand capacity of the transformer; Construct an evaluation model for each manufacturer and model of transformer according to the parameters related to the current short-circuit withstand capacity of the transformer screened out; During the operation of the transformer, obtain various parameters related to the short-circuit withstand capacity of the transformer and input them into the evaluation models of the corresponding manufacturers and models to obtain the evaluation results of the short-circuit withstand capacity of the transformer.

2. The dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information according to claim 1, wherein The calculation method of the reduction value of the current short-circuit withstand capacity of the transformer is as follows: δF = F O -F S Among them, δF is the reduction value of the current short-circuit withstand ability of the transformer, and F O is the short-circuit withstand ability value of the transformer before leaving the factory, and F S is the current short-circuit withstand ability value of the transformer. The F O and F S are calculated respectively through existing evaluation methods.

3. The dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information according to claim 1, wherein Also including: Set a correlation threshold and screen out the parameters with a correlation coefficient above the set correlation threshold.

4. The dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information according to claim 1, characterized in that, The operation time is evenly distributed throughout the entire operation life period of the transformer.

5. The dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information according to claim 1, characterized in that During the operation of the transformer, monitor the parameters related to the current short-circuit withstand capacity of the transformer. When the change amount of the parameters related to the current short-circuit withstand capacity of the transformer exceeds the set change threshold, trigger an evaluation.

6. The dynamic evaluation method for the short-circuit withstand ability of a transformer based on full-life operation information according to claim 5, wherein, Set an evaluation interval time and intermittently evaluate the short-circuit withstand capacity of the transformer at the set evaluation interval time.

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