The increasing demand for electricity in the current era requires good electricity
distribution. One of the components that must be maintained in the distribution of
electrical energy is a transformer. Transformers are useful in order to carry out the
transformation of power (current and voltage) from the AC system to other current and
voltage systems with the same frequency. This transformer makes use of the
electromagnetic principle. UAT (Unit Auxiliary Transformer) functions as a step down
transformer that supplies power to the Atomizing Air Compressor and SFC (Static
Frequency Converter). Atomizing Air Compressor and SFC are auxiliary equipment used
to assist the process of starting the initial rotation for the turbine so that it can operate.
Efficiency is the ratio between the power that comes out of the transformer (Pout) and
the power that enters the transformer (Pin). This indicates that at 05.00 the transformer
load is large because the existing losses are large. In other words, the auxiliary
equipment charged to the UAT is working. The efficiency value becomes small because
the Is is small. Meanwhile, at 14.00, the efficiency becomes large because there is not
much load received by the UAT, which means that the losses are small and the
transformer works in ideal conditions. So, the efficiency value becomes large because the
Is is large.