Influence of Harmonics on the Working Efficiency of a 6/1.2 kV Transformer in a Pit Mine

Abstract

Explosion-proof transformers 6/1.2 kV is important electrical equipment responsible for
supplying electricity in underground mine electrical networks. A failure of this transformer will cause an
interruption in the power supply and loss of safety in underground mining. Usually, explosion-proof
transformers in underground mine electrical networks are designed and manufactured to work with ideal
parameters such as sinusoidal currents, and the network structure is symmetrical. However, today in
underground mine electric networks, many power electronics are connected to the network, such as
inverters and soft starters. As a result, a current flowing through the transformer is non-sinusoidal,
overloading the transformer even by working with the design specifications. This paper studies the
influence of harmonics on the working efficiency of a 6/1.2 kV transformer in a pit mine. Research results
suggest reasonable solutions for transformer operation to ensure longevity and not cause damage to the
transformer.