Research On Optimal Planning,dispatching And Control Technology Of Prefabricated Energy Storage Power Station For Microgrid

The prefabricated energy storage power station for microgrid integrates energy storage system,power electronic converters,gird-connected interface of distributed generation and management control system into a movable steel box.It is a miniaturized integrated scheme of power station for island microgrid,which is very suitable for power supply in remote areas such as islands,pastoral and border areas.However,due to the high cost of construction and operation of the prefabricated energy storage power station for microgrid,and the fact that the control technology is still immature,the promotion and application of the prefabricated energy storage power station for microgrid is limited.Therefore,it is of great practical significance to study the optimal planning,dispatching and control technology of prefabricated energy storage power station for microgrid to meet the application needs of weak power scenarios in remote areas,which is important for reducing the construction and operation costs and improving the operation economy and stability of the prefabricated energy storage power station.The main contents of this paper are as follows:(1)In view of the problem of energy storage unit selection of prefabricated energy storage power station for microgrid,a multi-attribute decision-making method based on on interval type 2 fuzzy sets is proposed to ensure the objectivity and accuracy of selection results.First,by analyzing the economic,technical,and environmental impact of each energy storage scheme under the weak power scenario in remote areas,the hierarchical structure and index system of energy storage selection for microgrid are established.Then,the interval type 2 fuzzy sets is introduced into the decision-making process of the selection of energy storage,and the approach to the ideal point method based on the interval type 2 fuzzy sets is proposed to obtain the comprehensive weight of each index,the sequence of energy storage alternatives is completed,and the most suitable type of energy storage for prefabricated energy storage power station is determined.(2)In view of the capacity configuration for the energy storage system and distributed power generation in the prefabricated energy storage power station,a capacity optimization method which considering the equal annual cost is proposed to reduce the construction cost of the prefabricated energy storage power station while ensuring the system demand.First,the lowest annual investment and operation cost is taken as the objective function,an optimal configuration model considering various costs and constraints is established.Then,the large M method is used to linearize the model,the software CPLEX is used to solve the model,and the optimal configuration results are obtained.Finally,the impact of fuel price and power supply reliability on the optimal configuration is analyzed.(3)In order to further improve the operation economy of the prefabricated energy storage power station for microgrid,an energy optimal method which considering source-side and loadside uncertainty is proposed.First,the uncertainty model of the source and load is established by using triangular fuzzy number,and the energy optimization model with the lowest operation cost as the objective function is proposed by considering the load-side resources and system operation constraints.Then,a hybrid duration rolling optimal strategy based on adaptive confidence is proposed,which reduced the model’s dependence on accurate prediction and realized the real-time coordination of the model’s robustness and economy.Finally,the uncertain programming theory is used to transform the model,and the effectiveness of the proposed energy optimization method is verified by an example.(4)In order to ensure the SOC balance of the different energy storage units and reduce the voltage deviation,an adaptive droop control strategy of energy storage system is proposed.First,the SOC equilibrium term is added to the traditional droop control equation,then the adaptive virtual resistance and voltage compensation factor are introduced into the control equation by considering the line impedance and voltage deviation.Then,the small signal model of the proposed control strategy is built,and the influence of control parameters on the system stability is analyzed.The simulation results verify the correctness of the proposed adaptive droop control strategy.(5)Considering that the prefabricated energy storage power station is running without large grid support and has low inertia,a virtual inertia control strategy for t the converter of the energy storage power station is proposed considering parameter adaptation.First,virtual inertia and virtual damping are introduced into converter control by analyzing the inertia damping characteristics of traditional synchronous generators.Then,by analyzing the operation of the system when the power fluctuates,the adaptive adjustment strategy of the control parameters is proposed,and the small signal model of the proposed adaptive virtual inertial control strategy is built,and the influence of the control parameters on the system stability is analyzed.The simulation results verify the correctness and superiority of the proposed adaptive virtual inertia damping control.