New findings on bypass damping filter in increasing subsynchronous resonance damping of series compensated system

Subsynchronous resonance (SSR) has three categories, namely induction generator effect, torsional interaction and torque amplification. Bypass damping filter (BDF) was generally considered particularly effective for the induction generator effect. In this study, it is shown that BDF is also an effective countermeasure for torsional interaction and transient torque amplification. In addition, it can help reduce transient overvoltage of the series capacitor in a series compensated system. The parameter tuning method for BDF is proposed, based on electrical damping analysis and criterion for torsional stability. The SSR damping effectiveness of BDF in a series compensated system is verified by electrical damping analysis, torsional mode analysis and time-domain simulation.