  As a new type of microgrid structure, AC-DC hybrid microgrid can efficiently
consume new energy distributed generator based on photovoltaics, which is very
suitable for microgrid systems with electric vehicles as the main load. Unlike
the AC microgrid, the DC bus of the AC-DC hybrid microgrid is a low-inertia
system. How to improve the DC bus inertia of the AC-DC hybrid microgrid system
and the stability of the DC bus voltage become particularly important. Based on
this, this paper presents a method for flexible control strategy of microgrid
bus voltage based on multi-node droop. By considering the P / U droop
characteristics of DC ports of power electronic equipment such as energy
storage and electric vehicle charging-discharging equipment, different types of
distributed generator are comprehensively considered. The power reserve rate
and energy reserve rate, through curve shift and other adjustment methods,
improve the DC bus inertia, which effectively guarantees the stability of the
microgrid system voltage. The validity of the proposed method is verified by
building a matlab / simulik simulation system.
