Top oil heat distribution pattern of ONAN corn oil based transformer with presence of hot spot study using FEMM

Abstract

Transformer thermal modelling is a crucial aspect to be considered as this may help the determination of heat capacity of transformer. This paper present, simulation study on Oil Natural Air Natural (ONAN) transformer heat distribution pattern with and without presence of hot spot temperature (HST). This paper aims to compare the effects of different HST value at different locations inside the transformer unit as well as to evaluate the top oil thermal behaviour of corn oil as cooling mechanism in a transformer. To achieve aforementioned objectives, three HSTs were introduced to the 30 MVA transformer winding to find the total heat build-up in the top of the transformer tank. The outcome of thermal properties is examined using x-y temperature plot. From the results found that the location of HST affects overall transformer’s temperature. HST at the top of the winding give a significant effect compared to when HST is at the bottom of the winding. It is also evident that the usage of corn oil reduced the temperature distribution of the transformer. The findings suggest that the temperature distribution study especially on transformer is important to monitor in-service transformer in a non-invasive manner.

Effect of Hot Spot Temperature to the Temperature and Current Distribution in Transformer-Oil Based Nanofluids

“…transformer with the presence of HST A, HST B and HST C respectively at the top of HV winding. The reason why all HST value is located at top of HV winding is because there is a significant increase when HST is located at the top of HV winding compared to the bottom of HV winding [2,[6][7][8][9]. Figure 8 illustrates the comparison of temperature distribution at the top part of the transformer tank using mineral oil and transformer oil-based Al2O3 nanofluid with the presence of all HST.…”

“…In the year 1886, William Stanley introduced the first transformer for commercial used. The efficiency of this machine is generally higher than 95% since there is no moving part in the transformer [2].…”

“…The transformer oil-filled was introduced to overcome the heat dissipation problem in high rated transformer. This is because the failure of transformer to dissipate heat may reduce the lifespan of transformer [2]. George Westinghouse is the person who immerse the entire transformer in a tank of oil and spaced the laminations in the core so that the oil could circulate by convection among them [1].…”