Research On Control Strategy Of Small Community Energy Router Based On Distributed Energy

The energy router is the energy hub and control center for the integration of distributed energy into the power grid.It can realize the energy flow of distributed energy,energy storage devices and AC/DC loads between different interfaces,and can also realize the mutual conversion of various power forms.In this paper,a small community energy router based on distributed energy is taken as the research object,and its topology and control strategy of AC/DC interface converter are discussed and studied.The specific work includes :According to the instantaneous power balance principle of the energy router,the virtual synchronous generator control(VSG)strategy of the inverter is designed,including the virtual governor for controlling active power and the virtual exciter for controlling reactive power,so as to realize the control of the AC side port.Through MATLAB/Simulink simulation,the simulation model of virtual synchronous generator control strategy is built,and the effectiveness of virtual synchronous generator control strategy is verified.Aiming at the shortcomings of the traditional DC/DC chopper,two control strategies of DC/DC chopper are designed.First,the bidirectional DC/DC chopper introduces the droop control strategy on the basis of the voltage outer loop current inner loop control.Second,according to the rotor mechanical equation of the DC motor and the electromotive force balance equation of the stator,the bidirectional DC/DC chopper introduces the virtual DC motor control on the basis of the voltage and current double closed loop to realize the control of the DC side port.Through MATLAB/Simulink simulation,the advantages and disadvantages of the two control strategies and the influence on the dynamic performance index of the system are compared and analyzed.In the traditional pre-synchronization control mode with phase-locked loop(PLL)module,the small community energy router system of distributed energy is prone to voltage distortion and sag during the switching from island mode to grid-connected mode,which leads to the problem that the system cannot be smoothly connected to the grid and the waveform has a high distortion rate.A presynchronization control strategy without phase-locked loop based on phase angle compensation is proposed.