Research On Optimal Control Strategy Based On Microgrid Hybrid Energy Storage

Since the renewable energy of new energy will be an inevitable development direction in the future,the development and utilization of renewable energy has become one of the important issues to be solved worldwide.The energy storage system,as a kind of energy buffer and storage link,plays a significant role in the microgrid.First,the principles and characteristics of supercapacitors and lithium batteries in hybrid energy storage were analyzed.A series RC equivalent circuit model was selected as the equivalent circuit model of the supercapacitor,and a Rint equivalent circuit model was used as the lithium battery equivalent circuit model.The basic principle of fuzzy algorithm and its application in energy storage system were introduced.The input and output of fuzzy controller and other parameters were determined.Secondly,in order to realize the flexible matching of the voltage and capacity of the hybrid energy storage system,a method in which a supercapacitor and a lithium battery were connected in parallel through a power converter was selected.A Buck-Boost power converter was selected on the supercapacitor side,and a Boost power converter was selected on the lithium battery side.Aiming at the problems of the capacitor voltage and low energy density of the supercapacitor,a power matching method was selected to determine the capacity of the supercapacitor,and a hybrid energy storage system model for the supercapacitor and lithium battery was established.Finally,a hybrid energy storage optimization control strategy based on fuzzy algorithm was proposed,an adjustable pulse generator was designed,a hybrid energy storage parallel control system combining a Buck-Boost converter and a Boost power converter was built,and simulation in MATLAB.The simulation results and experimental verifications show that the proposed hybrid energy storage control method can maintain the bus voltage stability,suppress system oscillation,and increase the service life of the hybrid energy storage system.Figure36;Table7;Reference 57...