A Virtual Resistance Optimization Method Based on Hybrid Index in
Low-Voltage Microgrid
Abstract
The introduction of virtual resistance can effectively suppress the
circulating current between microsources and improve power allocation in
low-voltage microgrid, but it also causes the voltage deviation of
microsources' inverters. An optimization method of virtual resistance
based on hybrid index is proposed in order to suppress circulating
current and improve voltage deviation at the same time in this paper.
The gradient descent method is used to design the virtual resistance
optimization process, aiming at the optimization of hybrid index
composed of circulating current and voltage deviation. The constraints
are deduced with power quality requirements, capacity limitation and
static stability, and then virtual resistance values are optimized. The
effects of switching load and microsource on the optimization results
are analyzed through the simulation of low-voltage microgrid, and the
simulation results show that the virtual resistance optimization method
can significantly suppress circulating current while improving power
quality.