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Detection Technology

Safety measures before high voltage test

time:2020/11/3   source:华天电力  reading:822 time

Insulation defects of high-voltage test transformers are an important factor leading to equipment failures. A large part of the current accidents in the power system are caused by insulation defects. Therefore, in order to effectively reduce the probability of accidents, power professionals can use various high-voltage test methods to effectively test the data and information of the equipment during operation, so as to judge the feasibility of equipment operation. With the continuous improvement of the current power market development, power companies are in fierce market competition. In order to effectively occupy the market, gain an advantage in the competition, ensure the quality of power equipment, and ensure the safety in use is for power companies to improve their market. An important means of competitiveness.


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There are many types of high-voltage test transformers. Under normal circumstances, the high-voltage test of power transformers can be divided into two categories, characteristic test and insulation test. The characteristic test is mainly to test the main circuit contact resistance, ampere-volt curve, GIS, polarity, etc. of the circuit breaker of electrical equipment such as power transformers. The insulation test includes two types: destructive and non-destructive. The former involves withstand voltage tests such as DC and AC. Because of the higher voltage, it is easy to find defects in the equipment during the test, but because it is destructive Therefore, it is easy to damage the insulation of the equipment during the test, which greatly reduces the length of its life. The latter is generally tested with non-destructive methods, and defects in the overall electrical equipment can be found, but due to the relatively low voltage, the sensitivity is relatively low. The effects produced by different tests are also different, but in actual tests, non-destructive tests are still a more common test method.


High-voltage test transformers are easily damp, usually caused by their outer skin. Under normal circumstances, the electrical properties of water molecules in the electric field are positive, but if a positive voltage is applied to the windings of the transformer, it will cause the water molecules to change, and the amount of water will continue to decrease, so the amount of current passing through the transformer will also change. less. When the applied voltage is negative, the amount of current passing through the transformer will increase. But in fact, not all transformers are affected by voltage polarity. For example, new power transformers generally do not suffer from moisture. Therefore, the water content in new transformers is extremely low, or even negligible. In this way, there is no certainty between the polarity of the test voltage and the current leakage.


In order to ensure safe and accurate work, power transformers are an important guarantee for the safe operation of power high-voltage test transformers. In the high-voltage test, the professional requirements are high. Therefore, professional and technical personnel with strong professional knowledge should be selected for the test. At the same time, various safety protection measures should be taken before the test, and the test skills should be flexibly mastered during the test. Try to avoid the occurrence of various factors that affect the test results, so as to ensure the accuracy of the test results.


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