Select Page

Learn About Transformer Insulating Oil Dielectric Strength (breakdown voltage) Tester


In the power industry, transformers are a vital piece of equipment. They are used to convert high-voltage electrical energy into low-voltage electrical energy to meet various power needs. However, in order to ensure the safety and efficiency of the transformer, we need to conduct regular withstand voltage tests on it.

What Is Bdv Test Of Transformer Oil?

The withstand voltage test is a method of checking the insulation performance of electrical equipment by applying a voltage higher than the rated voltage to test whether the equipment can withstand this pressure. During the voltage withstand test of a transformer, we usually apply a voltage higher than the normal operating voltage to simulate the highest voltage condition that may be encountered.

However, when the transformer oil is subjected to a withstand voltage test, breakdown may occur if its dielectric strength is exceeded. This is because under high pressure, the gases in the oil will be ionized, forming conductive channels, causing electric current to flow through the oil through the equipment, which is a breakdown phenomenon.

Why does transformer oil breakdown?

This is mainly related to the properties of transformer oil. Transformer oil is an insulating liquid. Its main function is to isolate live parts and grounded parts to prevent current from passing through. However, transformer oil itself is not completely non-conductive. In fact, when oil is hit with high voltage, the gases in it become ionized, creating conductive pathways. Additionally, impurities in the oil may cause breakdown.

How to avoid or reduce the occurrence of breakdown?

First, we need to choose a test voltage that is high enough to ensure that the insulation strength of the device can withstand this pressure. Secondly, we need to maintain and inspect the transformer regularly to ensure that its insulation performance is good. If any damaged or aged parts are found, replace them immediately.

Finally, we also need to train operators so that they understand how to perform the pressure test correctly.