Optimal Operation Technology For Microgrid In Large Business District

Due to the shortage of energy resources and climate change caused by the process of fossil energy consumption,how to develop and invoke the new energy is the inevitable trend and strategy of energy development in the future.However,the new energy sources will also cause unavoidable impacts and influence on the power grid in the process of power generation and grid connection,especially the microgrid with small energy magnitudes.When large-scale electric vehicles and new energy sources are integrated into the microgrid,the impacts are even greater due to their small magnitudes,which have a greater impact on the power quality of voltage waveforms and voltage levels,making the microgrid operation process a safety hazard.The cooperative optimization problem of the CCHP microgrids is to optimize the operation variables based on the power flow equation under the condition that the structural parameters,cool/heat/electric coupling relationship and operation equipment constraints of the microgrid system are acknowledged in order to realize the optimal solution of the microgrid seeking for the optimal economic,safe and stable operation.Due to the active-reactive power regulation capability of the soft open point and the distributed air-condition virtual energy storage,which are used to regulate the power quality of the grid,the active-reactive power of the grid can be adjusted in a very agile way,which not only makes the tidal distribution of the grid more reasonable,but also reduces the network loss of the microgrid and the abandoned power of renewable energy.thus ensuring the stability,safety and economy of the microgrid operation effectively.This paper focuses on the synergistic optimisation of CCHP microgrids in large business districts which focuses on the following issues below:(1)Research on the "source-network-load" co-optimisation of CCHP microgrids,using distributed power sources such as PV systems and CCHP units as the "source" layer;using intelligent soft switches as the network layer coordination,regulating the active power and reactive power at both ends of the switches to improve the consumption of renewable energy.By constructing a "source-network-load" co-optimisation model,with the maximisation of social benefits and the minimisation of voltage deviation as the objective function,the "source-network-load" microgrid for large business districts is established.By constructing a "source-network-load" co-optimization model,the "source-network-load" multi-objective co-optimization model is established with the objective function of maximizing social benefits and minimizing voltage deviation.Through the simulation results,the operating model proposed in this chapter are better than the remaining optimization models,and the effectiveness of the proposed model is verified.(2)Research on the optimal operation of the "source-network-load-storage" CCHP microgrid.Due to the high investment cost of energy storage system,the configuration of energy storage is closely related to the operation mode of microgrid.The outer layer uses a particle swarm algorithm to find the optimal annual equivalent investment cost and operation and maintenance cost of the energy storage configuration,while the inner layer uses a robust optimisation model to deal with the source and load uncertainties and transforms it into a simple MILP model by using pairwise theory.The objective function of the inner layer is transferred to the objective function of the outer annual equivalent investment cost by converting the daily operating cost to the adult operating cost.The experiments show that although the total cost increases,the maximum voltage offset decreases and the energy storage configuration costs decrease,thus verifying the effectiveness of the model optimization method.(3)Research on the "source-network-load-storage-vehicle" microgrid co-optimisation problem,the parameters of each electric vehicle are obtained using Latin hypercube sampling,and the NJW clustering method is used to cluster the electric vehicles for unified dispatch management.Considering the uncertainty of distributed energy sources and the two-stage robust optimization approach to deal with the uncertainty of PV and load,the column and constraint generation algorithm(C&CG)is used to solve the main and sub-problems of the model.Compared with free charge and discharging EV users,considering the income increase of EV users with orderly charging and discharge,reduced load peak and valley difference,reduced voltage fluctuation range and decreased network loss value,verified the effectiveness of the method.