Research on Energy Router with VSG Based on Impedance Remodeling Harmonic Suppression

As the core of regional energy interconnection, the energy router controls the energy flow and interaction, and feeds back to the energy internet dispatch center through coordinated commands, and then carries out the collection and control of the local energy network and the flow of the information network. However, the large number of nonlinear uncertain loads connected to the grid, coupled with the basic topology of the energy router consisting of power electronics, increases the harmonic content of the input and output, far exceeding the tolerance of harmonics on the grid side and the user side. The addition of a virtual synchronous machine (VSG) can compensate for the low inertia and low damping at the power electronic interface of the energy router and simulate the operation of synchronous generators and synchronous motors through the VSG control strategy to increase the output power of the energy router ports and reduce reactive power compensation, but also increase the harmonic content. The harmonic suppression method using impedance reshaping can improve grid-connected power quality by changing the line harmonic flow direction and increasing the virtual impedance to suppress the harmonic currents generated by the grid harmonic voltage, which makes the nonlinear load harmonic currents flow to the VSG.