In future, Distributed Generation (DG) and charging station penetration (as a result of electric vehicle development) will grow rapidly. Both of them will be able to connect directly into distribution transformer. Their penetration enables to change the daily loading pattern of a distribution transformer. During this time, many studies have been conducted in order to determine the DG effect and the charging station to the aging of the transformer. However, those studies have not investigated the effect on the transformer directly. Under their penetration, the liquid insulation may experience different electrical and thermal stress. Therefore, a study to evaluate the condition of the transformer insulation directly will be offered, especially on the transformer oil. In this study the effect of temperature fluctuations as an illustration of the penetration of EV charging and DG on the transformer to the transformer oil characteristics is investigated. Temperature fluctuations are made to resemble the transformer loading profile when there is penetration of EV charging and DG. The evaluation is performed by analyzing physical, electrical, and DGA characteristics of transformer oil. Moreover, the analysis compares the result with effect of transformer daily load and constant temperature pattern. The results show that rapid temperature fluctuation makes the transformer oil quality reduce faster than it should be.
- Breakdown voltage test
- Dissolved gas analysis (DGA)
- Physical and electrical characteristic of transformer oil
- Rapid temperature fluctuation