The problem of the aging power transformer park is quite pressing. This is mostly due to the high costs of the new equipment. That is why most electric power companies strive to optimize their financial losses and extend lifetime of transformers already in operation. Doing so costs an order of magnitude less, without any adverse effect on power transmission and distribution. This article concerns the reasons of transformer aging and the possible ways to extend their life time.
Analyzing the special literature on operation of oil-filled electrical systems, it should be noted that the reasons of transformer aging most often mentioned are moisture, temperature and oxygen.
Adverse environmental factors and extreme operating conditions also play their part, albeit to a lesser degree. This is due to the fact that such extreme conditions influence is negligible compared to moisture, heat and oxygen, affecting the transformer and its components constantly.
Long exposure of transformer insulation to high temperature causes it to decompose and “age”. In the long run this causes malfunctions and failures of the equipment.
If there is moisture in the insulation system, this may cause decomposition of molecular chains, increase aging of cellulose and reduction of the dielectric properties.
Moisture most often enters the transformer from the air, through incorrectly installed or degraded gaskets and seals. It should be noted that water vapor may form from decomposition of cellulose. The higher the moisture level, the less is the dielectric strength of the insulation.
High oxygen and moisture levels in the oil cause the formation of bubbles, which lead to formation of cavities and local tension, provoking breakthroughs and failures.
To extend transformer service life, several measures must be taken. The condition of the transformer must be checked and tested, and the oil in the transformer must be filtered using special equipment.
The CFU filtration unit by GlobeCore removes solid particles form the oil. This unit is mobile and simple in operation and servicing.
CMM-CM machines, employing sorbents, are used for oil dehydration. An important features of these units is the ability to reactivate the sorbent inside the unit.
The CMM-M units remove water and gas from transformer oil. Depending on the initial condition of the product, it can be processed in one of the following modes:
- filtration with heating and thermovacuum purification;
Using the GlobeCore products allows to keep the performance of transformer oil as good as new, extending the lifetime of the oil, as well as transformer in general. Reliability of power transmission and distribution is improved, reducing costs of fresh oil purchase and losses due to equipment downtime