AGC Real-Time Control Strategy Based on DFT Method

The rapid growth of photovoltaic and wind power generation in our country has led to the increase of power fluctuation in the tie line, which means that the existing grid frequency modulation strategy is no longer applicable. At present, AGC control adopts closed-loop PI control, and its parameter value is determined empirically. Due to the fluctuations caused by the large number to renewable energy, it is difficult for PI control to achieve precise control and adjust the control strategy under the new situation. Therefore, the dispatching organization is urgently required to upgrade the existing AGC control strategy. In order to solve the above problems, this paper proposes an AGC real-time control strategy based on discrete Fourier transform (DFT). The strategy classifies the power fluctuations of tie line by DFT for separating the load fluctuations belonging to the primary frequency modulation and economic dispatch categories, and only compensates for the intermediate frequency part. The simulation results show that the strategy can realize the real-time tracking of the tie line plan power with a low number of command times, and maintain the safe and stable operation of the power grid.