Siddharth Kamila Subsynchronous resonance is a phenomenon in which one or more of the resonant frequencies of the turbine generator shaft in thermal power units coincide with a natural resonant frequency of the electrical system with a long radial transmission network with series capacitors, resulting in a voltage drop.

Sub-synchronous control interaction (SSCI) is a stability issue induced by the interaction of a doubly-fed induction generator's control system and a series-capacitor compensated electrical network. It might cause system instability if not addressed appropriately.