The Optimal Allocation Of Dispatchable Resources Considering The Flexibility Of Microgrid

In the independent microgrid,with the insufficient supply of fossil energy and the continuous expansion of the installed scale of renewable energy,the uncertainty of the grid is increasing day by day.The randomness of renewable energy and the fluctuation of load cause an increase in the peak-valley difference of net load after the superposition.In order to improve the microgrid’s ability to deal with uncertain disturbances and flexibly adapt to the frequent variability and strong uncertainty of renewable energy with high proportion of access,this paper proposes a method to enhance the flexibility of the microgrid by coordinating and complementing and optimizing the allocation of dispatchable resources on the source-storage-charge side.Firstly,the flexibility of the micro grid was quantitatively analyzed from the perspective of supply and demand balance,and the flexibility demand of the system for prediction error was accurately described by piecewise fitting method of Gaussian mixture model(GMM).Secondly,under the condition of considering various uncertainties,demand response resources are used as flexible resources to participate in scheduling,and multi-type distributed power generation units and energy storage are cooperated to provide adjustable capacity for the system.Finally,the improved particle swarm optimization(IPSO)algorithm was used to optimize the system capacity allocation,and an optimal allocation model was established with the capacity of multi-type units and load response capacity as decision variables,and the goal was to minimize the one-cycle investment operating cost and maximize the flexibility margin index of the system.The analysis of a numerical example shows that this method can greatly improve the overall flexibility of the microgrid while ensuring the system investment and operation cost is small.In addition,since a single form of energy storage cannot significantly improve the downscaling flexibility of the system due to its limited storage capacity,Power to Gas(P2G)technology provides a new way for the absorption and storage of renewable energy.The optimization of the operation and configuration of the power-gas interconnection system aims to improve the flexibility and comprehensive benefits of the coupling system.P2 G is taken as a special flexible resource to participate in the configuration and effectively improve the ability of the micro-grid system to accept renewable energy in multiple ways.In order to fully tap the complementary potential of multi-storage system,a two-layer optimization model of power-gas interconnection system with P2 G and energy storage is considered.Finally,the GA-IPSO algorithm and the software CPLEX was used to verify the feasibility of the established model.The proposed optimal configuration method involving demand response and P2 G technology has significant advantages in improving the flexibility and economy of the microgrid,and promotes the local consumption of renewable energy.