Live detection method for power capacitive equipment

Abstract

A live detection method for power capacitive equipment comprises the following steps: detecting MOV by adopting a leakage current third harmonic compensation method to obtain the condition of MOV leakage current; calculating the correlation degree between the leakage current values measured under different environmental conditions and external environmental factors according to a grey correlationanalysis method; selecting various corresponding measurement data from a previous power failure detection database, processing the data through an intelligent diagnosis algorithm, and establishing a state evaluation data model; carrying out live detection for the leakage current; using a straight-through current transformer to obtain end screen current and lightning arrester grounding current of the capacitive equipment, and obtaining current characteristic information of the equipment through a numerical analysis and fault diagnosis algorithm; evaluating the state of the capacitive equipmentin the obtained state evaluation data model, and comparing the state with the data in the step 4 to form a comprehensive comparative analysis result. According to the method, the operation and maintenance management level of the capacitive equipment can be improved, and large-area power failure accidents can be effectively avoided.

Description

technical field

[0001] The invention belongs to the technical field of electric power detection, and relates to a live detection method for electric capacitive equipment. Background technique

[0002] The capacitive equipment in the substation is the main electrical equipment in the power system. Its safe operation is related to the safety of the power grid and the quality of power. The safe operation of the capacitive equipment is of great significance to improve the economic and social benefits of enterprises.

[0003] Capacitive equipment mainly includes arresters, transformers, high-voltage bushings, voltage transformers, current transformers, etc. With the rapid development of my country's medium and low-voltage power grids, capacitive equipment has been widely used more and more. During the long-term charged operation of capacitive equipment, due to the influence of various factors (environmental pollution, chemical corrosion, heating caused by various reasons, electro...

Examples

Embodiment Construction

[0027] The present invention will be further described below.

[0028] A live detection method for electric capacitive equipment, comprising the following steps:

[0029] Step 1: Use the third harmonic compensation method of leakage current to detect MOV, and obtain the situation of MOV leakage current;

[0030] S1: Obtain MOA resistive current i by formula (1) r ;

[0031]

[0032] S2: Obtain the MOA capacitive coupling current i by formula (2) c ;

[0033] i c =jωC kk (u k2 -u k1 ) (2);

[0034] where k=1, 2, 3, ..., n;

[0035] Step 2: Calculate the degree of correlation between the leakage current value measured under different environmental conditions and external environmental factors according to the gray relational analysis method. The specific analysis is as shown in Table 1 to Table 5;

[0036] Table 1 Correlation degree between leakage current and external environmental factors when there is no rain in summer and autumn

[0037] Relative hum...

technical field

[0001] The invention belongs to the technical field of electric power detection, and relates to a live detection method for electric capacitive equipment. Background technique

[0002] The capacitive equipment in the substation is the main electrical equipment in the power system. Its safe operation is related to the safety of the power grid and the quality of power. The safe operation of the capacitive equipment is of great significance to improve the economic and social benefits of enterprises.

[0003] Capacitive equipment mainly includes arresters, transformers, high-voltage bushings, voltage transformers, current transformers, etc. With the rapid development of my country's medium and low-voltage power grids, capacitive equipment has been widely used more and more. During the long-term charged operation of capacitive equipment, due to the influence of various factors (environmental pollution, chemical corrosion, heating caused by various reasons, electro...

Examples

Embodiment Construction

[0027] The present invention will be further described below.

[0028] A live detection method for electric capacitive equipment, comprising the following steps:

[0029] Step 1: Use the third harmonic compensation method of leakage current to detect MOV, and obtain the situation of MOV leakage current;

[0030] S1: Obtain MOA resistive current i by formula (1) r ;

[0031]

[0032] S2: Obtain the MOA capacitive coupling current i by formula (2) c ;

[0033] i c =jωC kk (u k2 -u k1 ) (2);

[0034] where k=1, 2, 3, ..., n;

[0035] Step 2: Calculate the degree of correlation between the leakage current value measured under different environmental conditions and external environmental factors according to the gray relational analysis method. The specific analysis is as shown in Table 1 to Table 5;

[0036] Table 1 Correlation degree between leakage current and external environmental factors when there is no rain in summer and autumn

[0037] Relative hum...

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