# Research on Robust Day-Ahead Dispatch Considering Primary Frequency Response of Wind Turbine
## 1 Introduction
However, it fails to take into consideration the transient response of the speed governor. The situation is improved in [13], which takes into consideration the system inertia, governor ramp rate and frequency modulation dead band and establishes a more accurate primary reserve constraint. Through the optimal dispatch in the real-time market time scale, the dispatch strategy which ensures the abundance of the Primary Frequency Response (PFR) is developed. Within the framework of the Optimal Power Flow (OPF), the above research draws up the dispatch strategy that meets the demands of the primary frequency response. However, with the increase in the wind power penetration rate, the number of conventional units that can be dispatched in the power grid drops, which affects the primary reserve. It is therefore of great significance to fully consider the calculation of the frequency regulation capability of the VSG in wind turbines. The work in [14] elaborates on the impact of increasing the wind turbine capacity in power systems on conventional units and the reserve level and finds that the reserve and system operating costs are increasing. [PERSON], et al. [15] regard wind turbines as schedulable unit resources. It proposes two reserve allocation strategies of wind turbines and analyzes their advantages and disadvantages as well as the applicable scenarios. Based on the analysis, the author puts forward the method which integrates the two mentioned reserve allocation strategies. The method used to determine the reserve capacity through the fixed reserve capacity or a certain proportion of the wind power output is not an effective one, as it might lead to an inadequate reserve capacity or a waste of resources, even though it makesuse of the frequency regulation ability of the wind turbines. Moreover, the flexibility of the system primary reserve does not see an obvious increase. However, the VSG attains a faster adjustment speed, and in order to make sure that it goes with the traditional synchronous generator, the performance indexes are usually basically set to be the same as the traditional one. Therefore, it is probable to set up the primary reserve constraint that is more accurate and suitable for the optimal dispatch of the wind turbines, which will work with the other synchronous generators to enhance the frequency stability of the system by integrating the method to determine the primary reserve capacity of the traditional synchronous generator unit with the VSG technical standard. In fact, the above analysis of wind power primary reserve capacity allocation strategies fails to consider the uncertainty of wind power. In [16], considering that the increase of the grid connection of wind power in Europe in the future will lead to a greater prediction fault, the author proposes the coordinated dispatch at different time scales. The prediction accuracy of new energy varies at different time scales. Normally, other units put aside the reserve capacity for adjustment (different from the primary reserve) within the day-ahead market time-scale dispatch strategy, to ensure the real-time power balance of the system [14]. In this regard, with the two-stage robust optimization method, we can effectively coordinate the dispatch strategies in different stages for different targets. The work in [17; 18; 19] applies the method to the unit commitment problem and decide on the unit start-stop strategy for the first stage and the economic dispatch strategy for the second stage. [PERSON], et al. [20] considers wind power generation uncertainties as well as zonal reserve constraints under both normal and N-1 contingency conditions and proposes a robust model. As robust optimization is a three-layer optimization problem, it needs to be solved by decomposition algorithms such as the [PERSON]'s algorithm and column-and-constraint generation (CCG) algorithm [17; 21; 22].