A new thermal governor modeling approach in the WECC

Recordings of large generation trips in the Western Electricity Coordinating Council (WECC)(1) indicate that only about 40% of the simulated governor response actually occurs. This paper presents the development of a new turbine-governor modeling approach that correctly represents thermal(2) units that have demonstrated unresponsive characteristics as "base loaded" units, or as units with load-controllers. The developmental work included the creation of a WECC-wide system database based on disturbance monitoring and SCADA recordings of staged tests. The new modeling approach has been extensively validated against recordings from three WECC system tests and several large disturbances and has been recommended for use in all operation and planning studies in the WECC. Current effort is to obtain validated data for the new models from generator owners that will replace the developmental database. The new modeling results in improved dynamic simulations of thermal and hydro plant responses, of power flows in key interties, and of system oscillations following large generation trips.