Credible Power Capacity Evaluation for Load-side Resources to Participate in Power System Primary Frequency Regulation

With the gradual increase of the penetration rate of new energy with uncertainty in the power system, the conventional units that are the main force of primary frequency regulation (P FR) have been replaced, resulting in the weak capacity of the power system for primary frequency regulation. Due to the large investment in supplementary source-side resources, a large number of load-side resources existing in the power system can be used to participate in PFR. Due to the insufficient capacity of individual load-side resources, it is difficult for them to be directly controlled by the power system. This paper proposes using a Virtual Control Unit (VCU) to aggregate various load-side resources, providing P FR for the power system. Since the capacity of each load-side resource is uncertain, the total capacity of VCU is also an uncertain quantity. The VCU uses tagging to categorize load-side resources based on their capacity characteristics. It then employs a two- level aggregation method to aggregate these resources. Since When aggregating all kinds of load-side resources, the VCU needs to report the total capacity to the power grid, thus making it necessary to evaluate its credible power capacity. Through case study analysis, it is shown that the proposed strategy can effectively aggregate a large number of load-side resources to participate in P FR, proving its effectiveness. Further, by utilizing two-level aggregation of load-side resources with tagging, the power capacity characteristics can be parsed into mathematical expressions, greatly simplifying the aggregation difficulty, demonstrating its superiority. Additionally, after risk analysis, the capacity reported by the VCU to the power grid can ensure the maximum expected profit of the VCU, ensuring the sustainability of the strategy.