Adaptive Analysis Of Control Strategy Of Microgrid Inverter For Power Flow Calculation And Study Of Power Flow Algorithm

With the shortage of resources and the increasingly serious environmental pollution,distributed generation is of great significance for resource utilization,environmental protection,and adjustment of energy structure due to its high energy utilization,low pollution,clean and renewable characteristics.But in general,the output of new energy generation is often random and uncontrollable.If directly connected to the power grid operation,it will have adverse effects on the safety and stability of the system,and increase the complexity of power grid management.As an integration of new energy,energy storage and load,the microgrid has been used in the form of "good citizens" in the form of grid operation.It has attracted the attention of experts and scholars at home and abroad.Power flow calculation plays a fundamental role in state analysis and stability analysis of power systems.But the power flow calculation of microgrid needs to consider the node types of inverter nodes.It is often necessary to transform the inverter into PQ and PV type nodes by using the node type equivalent method.However,the equivalent condition of the node type and the type of the equivalent node are not much studied at present.Firstly,the control strategy of distributed generation access to microgrid is analyzed,and the equivalent node types of all control strategies in microgrid power flow calculation are analyzed and summarized.Based on the consideration of filter parameters,the corresponding node types of traditional droop control and robust droop control are compared and analyzed,and the characteristics of inverter control strategy that can be directly equivalent to nodes are summarized.Then,for the robust droop controller node,using the Newton Raphson method based on robust droop controller active power and reactive power constraint equation,construct the Jacobian matrix solution based on initial voltage.Then calculate the power flow of microgrid with inverter controlled by robust droop control strategy.Based on the fifth framework of EU microgrid system,the proposed algorithm is verified by the operation parameters supplemented.Finally,because of the light intensity,wind speed and randomness and fluctuation of power load,we build the model of photovoltaic power generation system,wind power generation system and load,and use Monte Carlo simulation calculating power flow of the micro grid,calculation results are analyzed.Based on the fifth framework of EU microgrid system,the power and load are replaced by random power flow model to verify the correctness and effectiveness of the proposed algorithm.Stochastic power flow calculation can greatly reduce the amount of computation,and the statistical results are more comprehensive than deterministic power flow,which is conducive to the planning and design of microgrid,and provide better decision information for the economic dispatch of microgrid system.