A method for fault diagnosis of power transformers

A technology for power transformers and fault diagnosis, which is applied in the measurement of electrical variables, instruments, and electrical measurement to achieve the effects of improving classification accuracy, simple algorithm structure, and improving accuracy.

CN106093612BActive Publication Date: 2019-03-19STATE GRID JIANGSU ELECTRIC POWER CO ELECTRIC POWER RES INST +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2019-03-19

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Abstract

The invention discloses a power transformer fault diagnosis method. The power transformer fault diagnosis method comprises the following steps of determining N fault types of a transformer, and determining corresponding fault characteristic quantities for diagnosing the N fault types; taking the fault characteristic quantities corresponding to the N fault types as a testing sample, and performing normalizing processing of testing sample data; combining any two of the N fault types, establishing X (described in the specification) SVM ( Support Vector Machine) secondary classifiers, and training the X SVM secondary classifiers, and optimizing a SVM kernel function using a method based on combination of K-fold cross validation and an artificial bee colony algorithm; calculating generalization errors of each SVM classifier according to the K-fold cross validation method; and diagnosing the N fault types using an improved reordering adaptive directed acyclic graph support vector machine method. The invention has a capability of well diagnosing the fault type of a transformer, can greatly improve the accuracy of transformer fault diagnosis, and provides a reliable basis for transformer maintenance.
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Description

technical field

[0001] The invention relates to a power transformer fault diagnosis method, which belongs to the technical field of power equipment state detection. Background technique

[0002] Judging the operating state of the transformer and its latent faults, so as to discover the nature and development trend of the internal faults of the transformer in time is of great significance for mastering the operating state of the transformer and the safe and stable operation of the power system. DGA (dissolved gas analysis) method is currently one of the most effective and simple methods to find early internal faults in oil-immersed transformers. Among them, the IEC three-ratio method has made a great contribution to discovering latent faults of transformers in the past equipment maintenance. However, in long-term practice, it is found that a considerable part of the DGA results of this method are not covered in this code, which leads to the inability to diagnose some faults....

Examples

Embodiment Construction

[0046] The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

[0047] Such as figure 1 As shown, a power transformer fault diagnosis method includes the following steps:

[0048] Step 1, determine N fault types of the transformer, and determine fault feature quantities corresponding to the N fault types for diagnosing.

[0049] Here N=8, that is, there are 8 types of transformer faults, namely: low-energy discharge fault, high-energy discharge fault, partial discharge fault, low-temperature overheating fault (t700 ℃), low energy discharge and overheating fault, high energy discharge and overheating fault.

[0050] When the transformer is in normal operation, the CH produced in the transformer oil 4 (methane), C 2 h 6 (ethane), C 2 h 4 (ethylene), C ...