Fuzzy PID Controller for Accurate Power Sharing and Voltage Restoration in DC Microgrids

Abstract

In DC microgrids, conventional droop control is widely used to perform power sharing of distributed energy resources. Although, this method is communicationless and reliable, it cannot achieve accurate power sharing and voltage restoration due to missing global information such as average output voltage and average power per unit. To solve this problem, this paper proposes a distributed secondary control level based on a Fuzzy logic controller. Thanks to the proposed method, accurate power sharing and average voltage restoration are achieved simultaneously. Based on voltage shifting method, secondary control level is simplified with the only one Fuzzy logic controller. Furthermore, with outstanding feature of the Fuzzy controller, both voltage and power allocation performances are enhanced in comparison with a conventional PID controller or a simple integrator. The proposed control scheme is verified by simulation in Matlab & Simulink.