In “dual-high” power systems

the lack of inertia and reserves makes frequency security a prominent concern. Embedding frequency constraints and coordinating the optimization of heterogeneous frequency regulation resources in dispatch are effective solutions. Therefore

this paper proposes a distributionally robust frequency constrained unit commitment optimization scheme considering load-side frequency support. First

the system frequency response process is analyzed

and a system frequency response model considering load-side frequency support is established

from which a set of frequency security constraints is constructed. Second

the uncertainty of renewable energy is characterized using fuzzy sets based on the Wasserstein distance

and a distributionally robust optimization model for unit commitment that includes frequency constraints is formulated. Due to the highly non-convex nature of the proposed model

a two-stage decomposition algorithm is employed for iterative solution. Additionally

an adaptive multi-directional cut-plane method is proposed to effectively link the master and subproblems. Finally

case studies are conducted based on modified IEEE 39-bus and IEEE 118-bus test systems. The results demonstrate the necessity of incorporating frequency constraints and the importance of load side frequency support in renewable energy power system dispatch schemes

validating the effectiveness of the proposed unit commitment scheme and the superiority of the solving method.