AC/DC hybrid micro grid voltage recovery control

AC/DC hybrid is a kind of structure forms of micro grid, to supply AC load and DC load. In order to realize the uniform distribution of DC power between AC converters, improve the DC bus voltage quality; this paper introduces a hierarchical AC converter control strategy. The first layer is the DC voltage-active power droop control method to realize the uniform load distribution; considering that droop control will lead to fall of the DC bus voltage, the second layer control method compensate voltage reference value of DC bus, to realize the recovery of bus voltage, and ensure the quality of the DC bus voltage. In this paper, control methods are analyzed by the root locus method, and the micro grid model is built based on the simulation of soft ware DIgSILENT, to validate the control strategy.