ADJUSTING THE VOLTAGE AND FREQUENCY BASED ON DROOP CONTROL FOR PARALLEL INVERTERS IN MICROGRIDS

Abstract

Droop control for load sharing between parallel inverters is one of the power sharing methods popular today because of its advantages compared with other methods. Some articles have presented traditional and improved droop control method. However, most studies aim at only load sharing for the inverters but not reducing the voltage and frequency deviation to improve power quality. Therefore, this paper shows the adjustment of the voltage and frequency method based on fuzzy logic with the aim to minimize the voltage and frequency deviation for improvement of power quality in microgrids. This controller consists
of a droop combined with fuzzy logic to control changes of the slope of the power curve when the load changes, thereby the voltage and frequency deviation could be adjusted. This proposed control method is called the droop-fuzzy logic control method. Experimental results confirm the validity of the proposed control.

Keywords: Droop control, fuzzy logic, inverters, microgrid, power sharing