Research On Control Strategy Of Optical Storage Microgrid Based On Virtual Motor Technology

Solar energy is one of the most promising renewable energy sources in today’s society,and photovoltaic power generation accounts for an increasingly high proportion of the total new energy generation.Photovoltaic power generation with energy storage devices to form a photovoltaic storage micro-grid can make good use of solar energy.With a large number of optical storage micro-grids connected to the grid,the use of power electronics is also increasing day by day.The large number of power electronics seriously affects the damping and inertia of the power system,making the power system lose stability when subjected to disturbances.With a high proportion of renewable energy and a high proportion of power electronics in the power system,the study of voltage and frequency stability has become a priority.In this context,this paper introduces Virtual DC Generator(VDG)and Virtual Synchronous Generator(VSG)into the optical storage microgrid,aiming to use virtual motor technology to make power electronics simulate the rotational inertia and damping characteristics of rotating motors,and to solve the problem of damping of power electronics on the power system.The aim is to use virtual motor technology to enable power electronics to simulate the rotational inertia and damping characteristics of rotating motors,and to address the impact of power electronics on the damping and inertia of power systems.The main research elements of this paper are as follows:(1)For a typical optical storage micro-grid system structure,the working principle is analyzed and the corresponding system model is established,including the PV power generation unit model,the energy storage unit model and the converter model,based on which the conventional control strategy of the optical storage micro-grid system is studied.(2)VDG technology is adopted to solve the problems of DC bus voltage stability and poor dynamic performance of the conventional control strategy of the energy storage converter.Firstly,the VDG model of the energy storage converter is established;secondly,the VDG control strategy of the energy storage converter is designed on the basis of the conventional voltage-current double closed-loop control;finally,an online optimization strategy of the VDG rotation inertia and damping coefficient parameters using BP network is proposed.(3)VSG technology is used to solve the problems of output power and frequency fluctuation of the conventional control strategy of grid-connected converters.Firstly,the VSG model of the grid-connected converter is established;secondly,the VSG control strategy of the grid-connected converter is designed on the basis of the conventional active-frequency control and reactive-voltage control loops;finally,BP network is also used to optimize the rotational inertia,damping coefficient,and integration coefficient of VSG online.(4)Reinforcement learning and intelligent optimization techniques are used to solve the frequency coordination control problem of multiple VSGs in optical storage microgrids.A Qlearning-based frequency control strategy is proposed to obtain the total power deficit according to the frequency variation;a power deficit optimization allocation strategy based on the HHO algorithm is proposed to obtain the power deficit allocation of each VSG,which finally realizes the coordinated frequency control of multiple VSGs in the optical storage microgrid.The simulation results show that the proposed energy storage converter VDG control strategy can effectively improve the stability of the DC bus voltage,the PV grid-connected converter VSG control strategy can improve the stability and response speed of voltage and frequency,and the power optimization allocation strategy improves the economic performance of the multiple VSG frequency coordinated control operation of the PV storage microgrid.The research results provide a good basis for solving the problem of the frequency coordinated operation of PV storage microgrid.The results of the study provide new ideas for solving the double-high characteristics of new power systems such as optical storage microgrids.