Effect of Power Quality on the Performance of Explosion-Proof Transformers in Mining in Vietnam

Abstract

When meeting customer demand, utility companies must consider power quality. Currently, the industrial power network in general
and the underground mine power network in particular have long feeder lines, supplying power to many nonlinear loads and power
electronic converters, which reduces power quality. Poor power quality can damage sensitive equipment and lead to costly repairs, leading
to lost time, data corruption, and lower productivity. In this paper, a fuzzy system is developed to determine the power quality of the
power network for different operating conditions and study its influence on the performance of the explosion-proof transformer in the
underground mine power network in Vietnam. The simulations and calculations were performed on Matlab-Simulink software for a
three-phase, 630-kVA, 6/1.2 kV explosion-proof transformer in power networks with variable power quality. A fuzzy system is developed
with four measurable inputs, including frequency deviation, voltage unbalance factor, total harmonic distortion of supply voltage, total
harmonic distortion of current, and an output variable, power quality. The simulation results show that the explosion-proof transformer's
performance decreases when the power quality degrades, and the proposed fuzzy system can accurately diagnose this.