Improving Electric Power Quality within the Power Supply System of Wide-strip Hot-rolling Mill Stand

The paper proposes studies of electric power quality indexes for 10 kV network supplying electric drives of the wide-strip hot-rolling mill stand equipped with thyristor electric drives. It provides the power supply diagram of the plate rolling shop. Information on the methods of experimental studies of the current and voltage spectral distribution with the use of a standard measuring device and software is provided. The paper shows the nature of higher-order harmonics content for units of the 10 kV distribution substation. It considers the method and system for reactive power control in the load center that ensures a step power change of the reactive-power compensator batteries and the following smooth fine adjustment by automatic control of synchronous motor excitation current. According to the algorithm proposed condenser batteries shall be operated in the basic mode and compensate a semi-constant component of reactive power.