Research On Multi-resource Peak Regulation Strategy Of Source-Grid-Load In Renewable Energy Power System

The grid-connected capacity of renewable energy such as wind power,solar and other renewable energy sources continue to increase,the fluctuation and uncertainty of their output make it increasingly difficult for the system to maintain the power balance,and the demand for flexible peak regulation resources also increases.In order to ensure the stable operation of power system,the flexibility resources of each link of source-grid-load need to be further explored.For this reason,this paper studies the method to improve the flexibility of the high proportion new energy power system from the three sides.The main work contents are as followsOn the power supply side,aiming at the problem that the nuclear power units with increasing installed capacity still operate at rated power,an optimal dispatching model considering the daily load tracking and peak regulation of nuclear power is proposed.First,the feasibility and safety of nuclear units participating in daily load tracking and peak regulation of the power grid are analyzed from the technical level,and the operational constraints of peak regulation for nuclear power plants are given.Secondly,the index of pollutant cost is used to quantify the impact of air pollutants represented by SO₂ and greenhouse gases represented by CO₂ on the environment,which is included into the objective function,and a comprehensive optimal dispatching model considering daily load tracking peak regulation of nuclear power is constructed by combining economic objective and environmental objective.Finally,by taking a local power grid in China as an example,through comparative analysis of the optimization results under different operating modes of nuclear power units,it is proved that the model proposed in this paper can relieve the peak regulation pressure of conventional units in a high proportion of renewable energy grid,effectively promote the consumption of renewable energy and achieve significant emission reduction effect.On the network side,aiming at the problem that the current HVDC tie-lie operation mode cannot balance the peak regulation demands of the sending and receiving power grids,the mechanism of peak regulation after tie-line is connected to the receiving power grids is analyzed,and the constraint of peak regulation margin of the receiving power grids is constructed based on this.Secondly,considering the characteristics of rapid,flexible and adjustable power changes of tie-lines,a coordinated and optimized dispatching model of tie-lines is established with the optimization objective of minimizing the operation cost of multiple regions at the sending power grid and receiving power grid and maximizing the accommodation of renewable energy.Finally,the brainstorming algorithm（BSO）based on step decreasing clustering is used to solve the model.Through comparative analysis with several traditional tie-lines operation modes,it is proved that the model proposed in this paper effectively balances the interest demands of the receiving power grid and the sending power grid,and realizes the integration of flexible resources in multiple regions.On the demand side,aiming at the existing conditions for time-sharing electricity price cannot follow the dynamic adjustment,and even prone to load a new peak of this problem,this paper proposes the use of Euclidean distance and improved differential cosine distance to dynamically measure the numerical similarity and angle similarity between the wind power curve and the demand curve,and establishes an electric vehicle dynamic peak shaving compensation mechanism based on the comprehensive similarity.Then,an optimized dispatch model based on the electric secondary dynamic peak regulation compensation mechanism is constructed,and real-time price incentives are used to guide electric vehicle users to participate in the response during the wind power reverse peak regulation period.In addition,the cost of discharge loss of electric vehicles with different states of charge（SOC）and depth of discharge（DOD）is quantified and incorporated into the user-side objective function,reducing the average number of charge and discharge cycles of electric vehicles per day.Finally,through a comparative analysis with the optimal charging and discharging strategies of electric vehicles under different electricity price mechanisms,it is proved that the model proposed in this paper improves the quality of demand response,reduces the total cost of users,makes full use of the distributed flexibility resources of load side,and directly promotes the accommodation of renewable energy.