Electricity Quality Assurance in Open-Pit Mining: Considerations of Today

This paper presents the today considerations of electricity quality assurance in open-pit mining. Improved technology and equipment for open-pit mining, the implementation of cutting-edge high-performance machinery require more efficient and reliable power supply to open-pit mining sites. Variable-speed drives, equipped with semiconductor converters, are used en masse in open-pit mining power systems, compromising the quality of electricity. Until recently, harmonic filters were the core solution to the electricity quality problem. As of today, variable-frequency drives are often used in combination with frequency converters, coupled with active front ends to improve the quality of electricity. The particularities of open-pit mining do complicate the design and choice of these electricity quality controllers. The problem could be addressed by a comprehensive approach that takes into account all the features of these electricity systems. The computer models proposed herein can be used to assess how electric drives with semiconductor converters affect the quality of electricity in open-pit mining. The paper shows that it is the type of the semiconductor converter-equipped drive and the proposed electricity quality controller that determine which mathematical model is to be used. It further presents the guidelines on how to choose electricity quality controllers, based on the developed methodology.