As a medium filled inside electrical equipment, insulating oil has many advantages such as insulation, heat dissipation, and arc extinguishing, and is widely used. For example, large power transformers currently use insulating oil for insulation and heat dissipation. But there is a discharge fault inside the transformer. Causing a series of chemical reactions such as light, heat, and electricity in insulating oil under the action of voltage. It is also crucial to regularly test the insulation oil in use to reduce its voltage resistance performance. In the following text, we will take a look at how to measure the breakdown voltage and dielectric loss factor of insulating oil.
Dielectric strength test of insulating oil
The breakdown voltage of insulating oil is a measure of its ability to withstand voltage inside electrical equipment and is one of the main methods used to test the insulation quality of oil products. We will use the GDOT-80A insulation oil dielectric strength tester to conduct oil withstand voltage tests here. According to relevant regulations, the test electrode should be made of brass. The capacity of the oil cup for placing electrodes should be 200 milliliters, and the oil cup should be made of porcelain or glass.
During the process of taking oil samples, it is necessary to preserve the insulating oil and avoid contact with other liquids or impurities, as well as prolonged exposure to air. The oil sample can be placed in the oil cup and left to stand for 10 minutes before the test can begin. The instrument automatically boosts the voltage from zero, and the boosting speed and current limit can be adjusted until the oil gap breaks down, and the breakdown voltage value is recorded. Repeat the test 5 times and take the average value. Compared with the standard breakdown voltage, the 500KV system should be greater than 60KV; The 330KV system should be greater than 50KV; The 220KV~60KV system should be greater than 40KV; The voltage level of 35KV and below should be greater than or equal to 35KV.
Measurement of insulation oil loss factors
Dielectric loss refers to the energy loss caused by the hysteresis effect of dielectric conductivity and polarization in insulating materials under the action of an electric field. Abbreviated as dielectric loss. The measurement of dielectric loss factor in insulation oil quality analysis is an important indicator that can determine the integrity of oil quality and indicate the degree of oil pollution and degradation during operation. Due to the small tan δ value of the insulation oil medium loss, the minimum is only 0.01%. So it is necessary to use a high-precision Xilin bridge for measurement. We recommend that you use the GDOT-80A insulation oil dielectric loss tester, which adopts an integrated structure for fast and efficient testing.
Post time: Aug-09-2024