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What are the serious consequences of overheating of power equipment in a substation?


Fault classification

Normally, operating power equipment will generate heat due to the action of current and voltage. It mainly includes heat generated by current effects and heat caused by voltage effects. When there is a defect or malfunction in the power equipment, the temperature of the defective or faulty part will change abnormally. This causes local heating of the equipment. Assume that the development of these hidden dangers is not detected and promptly stopped, which will eventually lead to equipment failure or accidents, which will seriously expand into grid accidents.


The heating faults of power equipment can be basically divided into two categories, namely external faults and internal faults. The basic characteristics are as follows:

1) External heating fault: It radiates infrared rays to the surrounding area in the form of local overheating, thermal faults of various exposed joints and connectors, and its infrared heat map shows the thermal field distribution centered on the fault point. Therefore, it can be visually judged whether there is a thermal fault from the heat map of the device, and the fault location and the severity of the fault can be accurately determined according to the temperature distribution.

2) Internal heating failure: its heating process is generally long, and it is stable heating, solid, liquid and gas in contact with the fault point, forming heat conduction, convection and radiation, and in this way the heat generated by the internal fault is constantly The ground is transferred to the device housing to change the thermal field distribution of the outer surface of the device. The transformer can basically find the overheat fault of the transformer in advance through regular variable ratio test and winding test.

Electricity production includes power production in power plants as well as transmission and distribution. The inefficiency of these two links has made it difficult to increase the capacity of the power industry, and accidents have occurred.

The problems in the production chain are mainly concentrated on poor infrastructure. Equipment is outdated, so energy conversion efficiency is low, and accidents often occur. In May of this year, a nuclear power plant in New York State, a fire and explosion accident, due to power plant transformer equipment barriers, and such accidents have occurred in the United States in recent years.



The test items are required for 110kV/220kV substation acceptance and maintenance testing(with corresponding tester types):

Test Object

Testing Item

Tester Type

Cable

Cable AC Hipot Testing

JYCX

Details

Cable Insulation Resistance Testing

JYM KYORITSU

Details

Transformer

Insulation Resistance of Winding

JYM KYORITSU

Details

DC Leakage Testing in 1min

JYDHV

Details

Winding Resistance Testing

JYR50S

Details

Winding Deformation Testing

JYP

Details

Turns Ratio Testing

JYT-A

Details

AC Hipot Testing

JYCX

Details

Short Circuit Impedance Testing

JYW6300

Details

Dan Delta Testing

JYC

Details

Oil Breakdown Voltage (BDV)Testing

JY6611

Details

Oil Tan Delta Testing

GTD-61A

Details

Switchgear

Circuit Breaker/Disconnector Resistance

JYL-200B

Details

Relay

Relay Performance

JY7003G

Details

On-load

On-load Switchgear Testing

JYK-I

Details

Tap Changer Dynamic Testing

JYK-I

Details

Instrument   Transformer

Current Transformer (CT)Testing

JYH-C

Details

Potential Transformer (PT)Testing

JYH-C

Details

Surge Arrestor

Zinc Oxide Characteristics Testing

JY6800

Details

1mA DC Reference Voltage

JYDHV

Details

Capacitor

Capacitor Current

JY6700

Details

Capacitor Inductance

JY6700

Details

Ground Grid

Grounding Down Lead Earth

JYD

Details

Related Articles:

What Test Items are Required for 110kV/220kV Substation Acceptance and Maintenance Testing?

What Tests Must be Done before the Transformer Leaves the Factory?

Main Factors Affecting the Operating Life of Transformers

What is the Purpose of Measuring the DC Resistance of the Transformer Winding?

Points to note in transformer oil breakdown voltage (BDV) test

DC winding resistance tester with 500 times tests on a single charge -JYR9310