Effects of phase-shifting transformers and synchronous condensers on breaker transient recovery voltages

This paper describes several system configurations that could lead to very high breaker transient recovery voltage (TRV) and rate of rise of recovery voltage (RRRV) in the presence of phase-shifting transformers, synchronous condensers, and switched capacitor banks. The special considerations involved in determining the most limiting TRV and RRRV are presented. Mitigation measures required for 15 kV and 115 kV breakers that are applied in the above system configurations are also presented. Simulation results presented are part of a design study carried out for the proposed extension to Granite Station in Vermont.