By hvhipot 
The AC withstand voltage test is the most effective and direct method for identifying the insulation strength of power equipment.
During the operation of power equipment, insulation will gradually deteriorate under the long-term effects of electric fields, temperature, and mechanical vibrations. Including overall deterioration and local deterioration, forming defects. For example, due to the concentration of local electric fields or the fragility of local insulation, there may be local defects. Each preventive testing method has its own advantages, as it can detect some defects and reflect the insulation condition separately. But the testing voltage of other testing methods is often lower than the working voltage of power equipment, which is not sufficient to guarantee safe operation. Although the test voltage for DC withstand voltage testing is relatively high, some insulation weaknesses can be discovered. Due to the fact that the insulation of power equipment is mostly composed of composite dielectrics, the voltage is distributed according to resistance under the action of DC voltage. Therefore, DC testing may not be able to detect the weaknesses of AC power equipment under AC electric fields, such as the difficulty of detecting generator defects in slots under DC.
The AC withstand voltage test meets the electrical conditions that the power equipment can withstand during operation. Meanwhile, the AC withstand voltage test voltage is generally higher than the operating voltage. Therefore, after the experiment, the equipment has a large safety margin, making it an important means to ensure safe operation. The weaknesses of AC power equipment under AC electric field may not be detected by DC testing, for example, it is difficult to detect slot defects in generators under DC. The AC withstand voltage test meets the electrical conditions that the power equipment can withstand during operation. Meanwhile, the AC withstand voltage test voltage is generally higher than the operating voltage. Therefore, after the experiment, the equipment has a large safety margin, making it an important means to ensure safe operation. The weaknesses of AC power equipment under AC electric field may not be detected by DC testing, for example, it is difficult to detect slot defects in generators under DC. The AC withstand voltage test meets the electrical conditions that the power equipment can withstand during operation. Meanwhile, the AC withstand voltage test voltage is generally higher than the operating voltage. Therefore, after the experiment, the equipment has a large safety margin, making it an important means to ensure safe operation. The AC withstand voltage test voltage is generally higher than the operating voltage. Therefore, after the experiment, the equipment has a large safety margin, making it an important means to ensure safe operation.
The AC withstand voltage test voltage is generally higher than the operating voltage. Therefore, after the experiment, the equipment has a large safety margin, making it an important means to ensure safe operation.
However, the test voltage used for AC withstand voltage testing is much higher than the operating voltage. Excessive voltage can increase the loss, heat generation, and discharge of insulation media, accelerating the development of insulation defects. Therefore, in a sense, the AC withstand voltage test is a destructive test.
Before conducting the AC withstand voltage test, various non-destructive tests must be carried out in advance, such as measuring insulation resistance, absorption ratio, dielectric loss factor TG ￠, DC leakage current, etc., and comprehensively analyzing the test results to determine whether the equipment is damp or has defects. If any problems are found, they should be dealt with in advance. The AC withstand voltage test can only be carried out after the defects have been eliminated, in order to avoid insulation breakdown during the AC withstand voltage test, expand insulation defects, prolong maintenance time, and increase maintenance workload.
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as AC withstand voltage test device) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.