Transformer power safety accidents are relatively frequent, so power enterprises pay more attention to high-voltage testing of powerhigh-voltage test transformers. This article analyzes the classification of test transformers and the safety measures that need to be taken before high-voltage testing of power transformers, and also specifically elaborates on the influencing factors, testing, and deviations that occur during high-voltage testing of power transformers.
During the operation of the power system, insulation defects in high-voltage test transformers are an important factor causing equipment failures. Among the current accidents in the power system, a large part is caused by insulation defects. Therefore, in order to effectively reduce the probability of accidents, during power operation, power professionals can use various high-voltage testing methods to effectively test the data and information during equipment operation, thereby judging the feasibility of equipment operation. With the continuous improvement of the current power market development, power enterprises are in fierce market competition. In order to effectively occupy the market, gain advantages in competition, ensure the quality of power equipment, and ensure safety during use, it is an important means for power enterprises to improve their market competitiveness.
Test transformers are divided into many types. Usually, high-voltage testing of power transformers can be divided into two categories: characteristic testing and insulation testing. Among them, characteristic testing mainly conducts tests on the main circuit contact resistance, volt-ampere curves, GIS, polarity, etc. of circuit breakers and other electrical equipment such as power transformers. Insulation testing includes both destructive and non-destructive types. The former involves withstand voltage tests such as DC and AC, because of the high voltage, it is easy to find defects in the equipment during the test, but because it is destructive, it is easy to damage the insulation of the equipment during the test, thereby greatly reducing its lifespan. The latter generally uses non-destructive methods to test it, which can find overall defects in electrical equipment, but because the voltage is relatively low, the sensitivity is also relatively low. Different tests produce different effects, but in actual testing, non-destructive testing is still a more commonly used testing method.
Transformers are easily affected by moisture, generally caused by their outer shell. Under normal circumstances, the water molecules in the electric field are positive in electrical polarity, but if a positive polarity voltage is applied to the transformer winding, it will cause changes in water molecules, the amount of water continuously decreases, so the current passing through the transformer will also decrease. When the applied voltage is negative polarity, the current passing through the transformer will increase. However, in reality, not all transformers are affected by voltage polarity. For example, new types of power transformers generally do not show moisture absorption, so the water content in new transformers is extremely low, even negligible. From this perspective, there is no certain relationship between the polarity of the test voltage and current leakage.
In order to ensure the safe and accurate operation of powerhigh-voltage test transformers, the power high-voltage test transformer is an important guarantee for its safe operation. High-voltage testing requires high professionalism, so professional and technical personnel with strong professional knowledge should be selected to conduct the test. At the same time, various safety protection measures should be taken before the test, and test skills should be flexibly mastered during the test, so as to avoid the occurrence of various factors affecting the test results as much as possible, thereby ensuring the accuracy of the test results.
