Research On Control Strategy Of Hybrid AC/DC Microgrid Interface Converter Based On Parameter Adaption

Microgrid is one of the important carriers for power system to absorb distributed renewable energy.Compared with the single DC microgrid and AC microgrid,the AC /DC hybrid microgrid simplifies the conversion link and conversion device,and can more flexibly and efficiently support distributed renewable energy access to the grid.It is one of the important components of the new power system.Interface converter is the core component of AC / DC hybrid microgrid,which plays an important role in coordinating the bidirectional power flow between AC / DC microgrids.Optimizing the control strategy of the interface converter is the key to improve the operation efficiency and enhance the stability of the whole microgrid system.The main work of this paper is as follows:The first section introduces the AC / DC hybrid microgrid topology,and the mathematical models of distributed wind turbine,photovoltaic and energy storage converters are established on this basis.According to the power distribution principle of AC/DC hybrid micro grid interface converter and the characteristics that the instantaneous power on both sides of the hybrid micro grid is in balance,a virtual synchronous machine(VSM)control model for AC/DC hybrid micro grid interface converter is established.The droop control strategy of AC/DC hybrid micro grid interface converter in island mode is compared with VSM control strategy..The second part in view of the fixed parameter VSM control strategy can’t juggle the speediness and stability of the problem,design the parameter adaptive control strategy of VSM,the control strategy can according to the change of the frequency adaptive adjust the moment of inertia and damping coefficient,can not only slow the decline of system frequency speed,Also can improve the system frequency recovery speed.Finally,in order to verify the feasibility of the parameter adaptive VSM control strategy,an AC/DC hybrid microgrid simulation test platform with TMS320F28335 as the control core is built,followed by a detailed analysis of the test platforms software and hardware.By comparing the experimental results with the simulation results,the results show that the improved VSM control strategy can improve the anti-interference ability of the system frequency in the AC/DC hybrid microgrid on the basis of increasing the system inertia and damping,taking into account the stability and rapidity of the system frequency response.