Improving the Electromagnetic Compatibility of Hot Rolling Mill Electric Drives at CJSC “MMK Metalurji” with Supply Network 34.5 $\text{kV}$

For more than a decade, the electric drives based on frequency converters with active front end FC-AFE and AC motors with voltages of 3 - 3.45 kV have been considered the most efficient among regulated electric drives of high power, from the point of view of reliability and economy. These drives are widely used in various industrial areas, where they are mainly used in units with frequent dynamic modes. In particular, in metallurgy FC-AFE are used as part of the main electric drives of rolling mills. The experience of industrial operation shows that when FC-AFEs operate in 6–35 kV in-plant distribution networks, unacceptable voltage distortions may occur due to the network configuration and PWM features of FC-AFEs. Such problems are present in the 34.5 kV distribution network of CJSC “MMK Metalurji” steel plant, where FC-AFEs are used as main electric drives of hot rolling mill. This paper is devoted to finding solutions to ensure electromagnetic compatibility of these FC-AFEs with the 34.5 kV supply network.