Study On Power Distribution Method Of Microgrid Based On Multi-Agent Consistency

With the continuous development of new energy power generation technology,the application of distributed power generation is becoming more and more extensive.The microgrid provides effective technical support for integrating various distributed power sources into the grid.However,in the microgrid running on the island,due to the distance between the distributed power sources and the common AC bus and the difference in the network structure,the reactive power output of each micro power supply cannot balance the load in the microgrid and the frequency of the microgrid system with droop control deviates from the rated value,which seriously affects the power quality and the safe and stable operation of the microgrid.Therefore,the paper discusses the reactive power equalization distribution of the microgrid and the system frequency offset.Firstly,the research summarizes the distributed power grid-connected inverter control strategy and micro-grid control mode.On this basis,the multi-agent consistency theory is studied.Secondly,the mathematical model of the micro-power inverter is established.The voltage-current double closed-loop controller is designed according to the model,and the frequency domain method is used to adjust the controller parameters,so that the micro-power equivalent output impedance is inductive while optimizing the controller performance.Thirdly,a distributed reactive power control strategy based on multi-agent consistency is proposed for the reactive power distribution of island microgrid.Each distributed power supply receives the reactive power of adjacent micro-power supply through communication network.The difference of reactive power is iteratively summed by consistency algorithm,and then the reference rated voltage amplitude of sag characteristic curve is self-adaptive compensated by proportional-integrator.The droop control realizes the power balance distribution and generates the frequency offset.A distributed frequency adjustment strategy with adaptive sagging coefficient is proposed.Distributed generations in microgrid acquire the information of adjacent micro-sources and local active power through low-bandwidth communication technology.Consistency algorithm and proportional integrator are used to obtain the self-adaptive regulation of sag coefficient,so that the frequency of microgrid system can be adjusted without error,and the accuracy of active power sharing load according to its rated capacity can be improved.Finally,the microgrid model is built in PSCAD,and the distributed reactive power control strategy with multi-agent consistency and the distributed frequency adjustment strategy with adaptive droop coefficient are simulated and verified by different working conditions.The results show that the designed control strategy realizes the power balance distribution,realizes the micro-grid frequency without static difference,improves the power quality,and enhances the reliability and stability of the system.