Frequency Security-Constrained Day-Ahead Dispatch Considering Flexible Load Power Support

The randomness and uncertainty of renewable energy have brought great challenges to the frequency security of power systems. In the foreseeable future, flexible loads with frequency support capability will be widely integrated. As flexible loads and power systems belong to different stakeholders, how to coordinate the benefits of both entities to ensure frequency security still needs to be studied. This paper establishes a frequency security-constrained day-ahead dispatch method considering the incentive price-based power support of flexible loads. Firstly, the power system model with frequency security constraints is constructed, where an innovative method for frequency constraints based on convex relaxation is used to reduce the calculation while meeting engineering requirements. Secondly, an incentive price decision-making strategy for frequency regulation between the power system and the flexible loads is proposed, where the Stackelberg game is introduced to depict the different interests of the two stakeholders. Furthermore, the multi-agent feature leads to the multiplication of the power system's incentive price and the flexible loads' frequency regulation capacity, which makes the optimization model bilinear. This challenge is transformed using the strong duality theory, and the frequency security-constrained day-ahead dispatch model considering the uncertainty intervals is established, which can be easily solved by the classic two-stage optimization algorithm. Case studies show that the proposed method can effectively incentivize flexible loads to perform power support, and has good effects in ensuring the frequency security and the robustness of the power system.