Optimization Of Microgrid Bi-directional Energy Storage Converter Model And Control System Analysis

With the development of new energy technology and micro grid techniques, the energy storage converter, as a important link between the public grid and the storage devices, has attracted more and more attention by scholars, and the energy storage and convert technology also changing rapidly.This paper mainly studies the bi-directional energy storage converter’s structure and the design method of the converter controller, the topology of the bi-directional AC-DC converter and the bi-directional DC-DC converter have been determined, some devices’ parameters of the circuit also been calculated with the method presented by this paper. Based on the topology and methods, models of the bi-directional AC-DC converter and the bi-directional DC-DC converter have been established, and the corresponding experiments proved the correctness of the models. Control structures of the bi-directional AC-DC converter and the bi-directional DC-DC converter modeled are designed based on the models, the difficult point of system debugging is focused on the controller parameters optimizing through the models and the controllers have been connected directly. A more well-suited system modeling and controller parameters optimizing method compared with the cut-and-trial method has been put forward combined the controller parameters optimizing methods of SISO system tool box, the system is stabilized and control effect is optimized by using the method of Bode diagram adjustment and parameters comparison. The process and results have been offered in this paper. The simulation of the bi-directional energy storage converter is built which met the requirements, the system model method and the parameters optimizing method are proved correct in simulation environment. The effectiveness of the proposed methods are validated through hardware experiments. In the hardware closed-loop debugging process, a double closed-loop debug method based on power balance theory is proposed according to the results of single closed-loop experiments, it could better guidance the processing of double closed-loop debugging.A lot of experiments shown that the methods above could achieved the controlling of the 500 kW bi-directional energy storage converter.