A method and an arrangement for controlling power supply in an electric mining unit, and a method for controlling power supply in a mining unit, as well as a mining unit

摘要

The invention relates to a method for controlling the supply of electric power to an electric mining unit intended for the processing of rock material, in which method, by means of a three-phase electric power network (2) provided in the mining unit and a mains switch (2') for connecting the mining unit to or for disconnecting it from an external electric power network (2"), and a power source (7), as well as at least one inverter (8, 8') and at least one transformer (14) and switches (3, 4, 5, 16, 17), the supply of electric power to the mining unit is controlled in such a way that when the electric power network (2) of the mining unit is connected to the external electric power network (2"), the first electric motor (9) and the second electric motor (13) are supplied from the external electric power network (2") or from the power source, and the power source (7) is simultaneously charged for at least part of the time from the external electric power network (2") by means of the inverter and the transformer or a charging system (15), and that when the second electric motor (13) is supplied from the external electric power network (2"), the first electric motor (9) is simultaneously supplied, if necessary, solely from the power source (7) provided in the mining unit, by means of the inverter (8). The invention also relates to an arrangement and a mining unit.