Supplementary Energy Storage and Hybrid Front-End Converters for High-Power Mobile Mining Equipment

To supply the high-power ac-drive systems of the mining equipment, several active front ends with dc choppers are used to ensure reliable operation and an acceptable harmonic current spectrum. Recently, the integration of the energy storage system with the mining equipment has received industry attention, particularly for peak load shaving and smarter energy management of the mines. Currently, the regenerative energy is often burned into the choppers and is not fed back to the grid. The industry is motivated to capture this regenerative energy since it can be as high as 60% of the motoring power, as high as 3 MJ in every operation cycle, and as high as 24-MW peak power. Therefore, there is a possibility of large cost reductions and component rating reduction. In this paper, we investigate the operation of the current state-of-the-art front-end converter systems for multimotor applications. In particular, we propose power conversion configurations and methodology to determine the suitable energy storage technology for the development of the multimotor mobile mining equipment that has encouraging incentives for both the manufacturers and the mine operators.