Hybrid Microgrid Load Distribution and DC Voltage Control

AC/DC hybrid microgrid is able to supply AC load and DC load. In order to distribute DC power evenly among interlinking converters and improve the DC power quality, a hierarchical control strategy for the interlinking converters is introduced. The first layer of the control strategy is to use the voltage-power droop control method, which can distribute load evenly. Because the droop control may cause DC voltage fall, the DC voltage reference value is compensated according to the second layer control method, which can recover the bus voltage , guarantee the voltage quality.Analyze this control strategy by root-locus method. A microgrid model is based on DIgSILENT. The control strategy is validated by simulation.