Research on Power System Frequency Control Strategy Considering the Limit Ratio of Wind Power

As a new renewable energy source, wind energy has developed rapidly in various countries in recent years, and the wake effect caused by its volatility and randomness brings wind speed differences to wind turbines inside wind farms, increasing the nonlinearity and uncertainty of the system. However, in the face of large-scale wind turbine cluster wind power system, traditional frequency control methods rarely consider the different wind conditions inside the wind farm, resulting in power imbalance between different wind turbines, increasing the actual frequency change rate of the system, and then limiting the limit ratio of wind turbines. Therefore, starting from the core problem of increasing the proportion of wind power that can be accommodated in the power grid, this paper proposes a doubly-fed wind turbine frequency rolling optimization strategy based on distributed model predictive control (D-MPC), which uses the internal optimization zoning rules of the wind farm to aggregate wind turbines with similar wind conditions, and incorporates the dynamic frequency of each zone into the top-level design of D-MPC. In addition, the maximum proportion of wind power connected to the grid is taken as the objective function of the system frequency control, and the MHE evaluator is constructed to estimate the unbalanced power in the wind farm in real time, which effectively reduces the curtailment rate of the power grid. Finally, with the help of PSCAD/EMTDC simulation platform, a power system model suitable for high proportion of wind power is constructed, and the simulation verifies that the proposed control strategy can maximize the proportion of wind power connection while ensuring the safe and stable operation of the power grid.