Damaging long-term overvoltages on industrial capacitor banks due to transformer energization inrush currents

This paper discusses the issues concerning industrial power systems with large capacitor banks and the energization of large furnace power transformers. The application of the capacitor banks could tune the system to a frequency that is excited by the furnace transformer energization current. Examples of situations occurring in industrial systems are shown with field-measured data. Transient and harmonic simulations are also shown describing the phenomena. The effects on the capacitors caused by the overvoltages that are created due to the resonant conditions are discussed. The paper also addresses relevant capacitor standards and how they are related to this type of system phenomena