The impact of large-scale grid-connected renewable power sources, such as wind generators and solar photovoltaic systems, on transient stability of synchronous generators is discussed in this paper. The permanent magnet synchronous generator with variable speed wind turbine is used in the simulation analysis as a wind generator model. The transient stability analysis is performed for IEEE 9-bus system model with high-penetration renewable power sources. The effect of fault ride-through (FRT) capability implemented for each power source on the transient stability is investigated.