AGC Control Strategy of Interconnected Power Grid Based on Dynamic Stratification

The grid connection of large-scale renewable energy increases the uncertainty of power system supply and demand, and the fixed mode of automatic generation control (AGC) method will be difficult to balance the contradiction between the diversity of frequency modulation demand and the direction of control strategy. In this paper, an AGC control strategy based on dynamic stratification is proposed. Firstly, a two-layer control framework is designed based on the AGC model of multi-area interconnected power network. The upper layer adopts the model predictive control for global optimal control, while the lower layer adopts the traditional proportional integral differential (PID) controller to realize the real-time control of single-area AGC units. Then, the dynamic stratification strategy is designed according to the control deviation of each region in order to adjust the control architecture according to the diversity of the frequency modulation requirements on the basis of ensuring the control effect, thereby effectively saving the system resources. The simulation results show that, compared with the fixed mode of the AGC method, the architecture of AGC control strategy based on the dynamic stratification can reduce the participation of the upper global controller under the premise that the frequency control effect of the power network is basically unchanged, thus reducing the online operation complexity of the interconnected AGC system.