Influence of renewable integration on frequency dynamics

Southern California Edison (SCE) is planning to integrate more than 7 GW renewable into their grid by year 2020. As transmission operator, they need to know whether their system can handle this big amount of renewable without compromising system frequency stability. Wind and solar generators connect to power grid via power electronics converters; they are not supplying system with inertia or governor response, which is different with traditional synchronous generators. The influence of renewable generations on system frequency control is investigated in this paper, including reduced inertia and primary control. Besides this, the interaction between frequency stability and voltage stability is analyzed including load modeling characteristics. The ramp down of renewable is studied together with loss of one big plant. Simulation results are demonstrated to validate the analysis. Suggestions for future research and studies will be identified.