Anticipatory AGC control strategy based on wind power variogram characteristic

Increasing penetration of wind power has a negative effect on system frequency deviation due to the fast variability and uncertainty characteristics of wind. In this study, a wind power variation prediction-based automatic generation control (AGC) feedforward control method is applied within the conventional AGC framework to minimise system frequency and tie-line deviations. Firstly, the variogram function is introduced for analysing the characteristics of wind power variations. A relationship between the variogram of wind power and the trend component of wind power is found and then a three-parameter power-law model is established. Then, the generation rate constrains of AGC generators is considered as the main constraint factor that influences wind power smoothing. By predicting the wind power variations in AGC control time-scale, a coordination AGC feedforward control strategy is proposed. The control strategy makes different types of AGC generators act in advance to improve the ability of the power system, corresponding to the forecasted ramp variations in wind power generation. Finally, the performance of the proposed coordination control strategy is verified and tested using the actual data from China. Simulation results show that with this new strategy, frequency deviation under wind power variations can be effectively decreased.