Market Analysis of High Voltage Test Transformer
2022-11-25
In recent years, power safety accidents are more frequent, so power enterprises pay more attention to the high-voltage test of power transformers. This paper analyzes the classification of high voltage test of power transformer and the safety measures to be taken before the high voltage test of power transformer. At the same time, the influencing factors in the high voltage test of power transformer, the test and the deviation in the test are described in detail.
In the process of power system operation, the insulation defect of equipment is an important factor leading to equipment failure. In the current power system accidents, a large part of them are caused by insulation defects. Therefore, in order to effectively reduce the probability of accidents, during power operation, power professionals can use various high-voltage test methods to effectively test the data and information during equipment operation, so as to judge the feasibility of equipment operation. With the continuous improvement of the current power market development, power enterprises are in the midst of fierce market competition. In order to effectively occupy the market, occupy an advantage in the competition, ensure the quality of power equipment, and ensure the safety in use is an important means for power enterprises to improve their market competitiveness.
1 Classification of high voltage test of power transformer
High voltage test transformers can be divided into many types. Generally, 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 and polarity of circuit breakers of electrical equipment such as power transformers. The insulation test includes destructive and non-destructive tests. The former involves DC and AC withstand voltage tests. Because of its high voltage, it is easy to find the defects of the equipment during the test. However, because of its destructive nature, it is easy to damage the insulation of the equipment during the test, thus greatly reducing the length of its life. The latter is generally tested by non-destructive methods, which can find the overall defects of electrical equipment. However, due to the relatively low voltage, the sensitivity is relatively low. Different tests have different effects, but in actual tests, non-destructive testing is still a common test method.
2 Safety measures before high voltage test of power transformer
During the high voltage test, its safety work is crucial, so before the test, reasonable arrangements should be made for various arrangements.
First of all, within the test site, hang warning slogans and pull up safety nets to keep passers-by away from the test site. So as to effectively ensure that personal safety will not be harmed during the test. In addition, relevant personnel are required to guard to avoid the intrusion of outsiders at the high-voltage test site, which may cause personal injury. Secondly, the high voltage test has high technical requirements, so the professional skills of the staff are highly required. It is not only necessary to ensure that the work participating in the test has high professional skills, but also to ensure the overall quality of the staff. This is of great significance to the normal and orderly development of high voltage test. At the same time, high voltage test is a work with high risk, so before the test, it is necessary to give a detailed description of the risk of the test part borne by each staff member, so that the staff can have a clear understanding, so as to take corresponding safety protection measures before the test, and pay special attention to safety during the test. In the high-voltage test, the operator is usually arranged to be a person with poor professional skills among the staff participating in the test. In order to prevent wiring errors from affecting the test, it is also necessary to check the wiring to ensure the safety of the test site.
3 Influencing factors of high voltage test of power transformer
3.1 Effect of polarity of test voltage on current leakage
The transformer is easy to get damp, which is generally caused by its skin. Generally, the electrical property of water molecules in the electric field is positive, but if a positive voltage is applied to the windings of the transformer, it will cause the change of water molecules, and the amount of water will decrease continuously, so the amount of current passing through the transformer will also decrease. When the applied voltage is negative, the amount of current passing through the transformer will increase. However, in fact, transformers are not all affected by voltage polarity. For example, new power transformers are generally not affected by moisture. Therefore, the water content in new transformers is extremely low, or even negligible. In this way, there is no certain relationship between the polarity of test voltage and current leakage.
3.2 Effect of temperature on high voltage test
The change of temperature will fully affect the insulation resistance. Therefore, when the external temperature keeps rising, the movement of molecules and ions in the insulation material will also speed up with the increase of temperature, which will lead to the increase of the polarity of the insulation resistance and the decrease of the insulation resistance. At the same time, in the process of rising temperature, the movement speed of water molecules in the insulation resistance will also be constantly accelerated, so that impurities on the insulation resistance surface can be rapidly dissolved, thus making the resistance rapidly drop. In addition, the reduction of insulation resistance is also directly related to the dirt on the surface. At the same time, the analysis of some research data shows that the change of temperature will also lead to the change of insulation absorption ratio of transformer. In this case, it can be divided into two cases. For the dry variable pressure Lu, the absorption ratio will increase with the increase of temperature. But once the temperature rises to more than 40 ℃, the absorption ratio will decrease. In other cases, the temperature will increase, and the absorption ratio will decrease.
Qingdao Hengfengyou Electric Group, is an electrical enterprise with transmission and distribution industry as its main business, integrating product research and development, manufacturing and trade. Designated suppliers for the world's top 500 enterprises.Its main products include oil-immersed transformer,dry-type transformer,electric furnace transformer,mining transformer ,rectifier transformer .It has been successfully sold to more than 50 countries around the world. Product certification is complete. Hengfengyou Electric will provide you with the best electrical product solutions. 【https://www.hengfengyou-electric.com ； sales@hengfengyou-electric.com ； WhatsApp：+86158 5325 2696（Jack） 】
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