Probabilistic OPF Model with DFIGs Participating in Primary Frequency Regulation

Primary frequency regulation (PFR) provided by the synchronous generators is weakened by less system inertia and more uncertainty due to the wind power. The capability of the doubly-fed induction generator (DFIG) is considered in the short-term economic dispatch (ED) for the PFR in the existing research, but the frequency constraint is not included. With the forecast error of the wind speed, a probabilistic optimal power flow (POPF) model with the DFIGs participating into the PFR is newly proposed to describe the probability distribution of the system cost and frequency. Parameters of the DFIGs under downward regulation are modified with the frequency change. The frequency deviation is introduced to the objective function. The impact of forecast error on the frequency is quantified.