| The contradiction between rural power grid construction and rural economy development is becoming increasingly prominent,and China is stepping up its efforts to upgrade and transform rural power grid.The increase in grid-connected capacity of renewable energy also makes rural power grid face multiple challenges of rational planning,safe and stable operation.The application of energy storage technology in rural power grid is a powerful measure to solve the above problems.At present,energy storage configuration technology research is mainly focused on a single scenario,and the needs of energy storage configuration research in multiple application scenarios are not considered enough.In order to further improve the power supply stability of rural power grid and fully tap the application potential of different types of energy storage in power grid,the multi-scenario energy storage configuration technology of weak rural power grids is studied.Firstly,the typical application scenarios of energy storage in power grid are analyzed from the perspectives of the power generation side,the grid side and the user side.And the requirements of different typical application scenarios for energy storage types and performance are summarized.The improved IEEE33 bus model is used to verify that energy storage can alleviate the low voltage of rural power grid and reduce the active power loss.Secondly,according to the analysis results of the suitable location and type of energy storage of the weak rural power grid user side,the battery energy storage is selected at the residential load to complete peak-valley shifting.Based on the change rate of load peak-valley difference,a method for energy storage configuration with limited peak load shifting is proposed,and the user-side energy storage configuration model is established taking into account the battery’s own performance constraints.And the influence of the value of limited value peak-valley filling coefficient on the peak-valley shifting effect and the economy of the energy storage system is analyzed.Next,based on the analysis of wind and solar power output characteristics and wavelet packet decomposition,a decomposition strategy is proposed to determine the target of stabilizing wind and solar fluctuation.And considering the hybrid energy storage power allocation,a renewable energy generation side energy storage configuration model is established.Taking the wind and solar power generation system data as an example,the influence of the layer number of wavelet packet decomposition and the hybrid energy storage system power allocation on energy storage configuration results is simulated and analyzed.The wavelet packet decomposition strategy can avoid the influence of subjective factors and obtain the optimal number of wavelet packet decomposition layers and the optimal wavelet packet basis.Then,comprehensively considering the voltage stability index and the economic cost of the energy storage system,the grid-side energy storage configuration model is established,which is based on the energy storage performance constraints and system operation constraints.The simulation analysis of energy storage configuration in weak rural power grid is used to verify the rationality of energy storage configuration and the importance of reasonable location of energy storage access.Finally,on the basis of the above studies,the influence of user-side energy storage configuration and renewable energy generation side energy storage configuration on the power grid is discussed.And a multi-application scenario collaborative planning method for energy storage configuration is proposed to reduce the interaction between source-grid-charge in the process of energy storage configuration,and realize the decoupling configuration for power grid energy storage system planning.A numerical example is used to compare the direct energy storage configuration with the collaborative planning energy storage configuration scheme to verify the effectiveness of the collaborative planning configuration. |
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