Analysis of the impact of sub-hourly unit commitment on power system dynamics.

• Co-simulation platform to study the impact of stochastic UC on power system dynamics. • Monte Carlo time domain simulations of stochastic differential-algebraic equations. • Study of the impact of different levels of wind power uncertainty and volatility. • Comparison of the impact of sub-hourly stochastic and deterministic UC models. This paper discusses the impact of the sub-hourly unit commitment problem on power system dynamics. Such an impact is evaluated by means of a co-simulation platform that embeds a sub-hourly stochastic mixed-integer linear programming security constrained unit commitment (sSCUC) into a time domain simulator, as well as includes a rolling planning horizon that accounts for forecast updates. The paper considers different sub-hourly sSCUC resolutions (i.e., 5 and 15 min) and different wind penetration levels (i.e., 25 and 50%). The focus is on the transient response of the system and on frequency variations following different sSCUC strategies, and different sSCUC wind power uncertainty and volatility. The case study consists of a comprehensive set of Monte Carlo simulations based on the 39-bus system. [ABSTRACT FROM AUTHOR]