The influence of ferroresonance on a temperature of voltage transformers in undeground mines

Mining networks are subject to high requirements in terms of operational reliability and safety. The occurrence of ferroresonances in the network is one of the causes of instrument transformers being overloaded, which can cause their damage. Therefore, it is necessary to avoid this phenomenon and design the instrument transformers in a way so that even in the event of ferroresonance there is no damage. In this article, attention is focused primarily on the thermal effects of overvoltage on instrument transformers of type TJE3 and TJC3, which are used in 6 kV mining networks in the area of the Ostrava-Karviná coal mining district.