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

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.