Primary voltage and current control for an autonomous inverter-based microgrid

This paper presents a new technique to design the voltage and current controllers in an inverter-based microgrid. The proposed method provides a systematic approach to design the controllers based on Lyapunov theory, and does not utilize the conventionally employed Proportional-Integral (PI) controllers, which are difficult to tune. Also, the use of PI controllers requires the simultaneous synchronization of tuning parameters in different stages of a larger system that render their use to be extremely tedious for large industrial applications. The novelty of the proposed controllers lies in the methodical design procedure and a flexibility to model the controller without analyzing the system equations and eigenvalues. Lyapunov Direct Method has been used to design the controllers for adequate active and reactive power sharing among different Distributed Energy Resources (DERs) present in a microgrid. The proposed controller has been tested on a test system and has manifested its advantage over its conventional counterpart in terms of less settling time, lower overshoot, and zero steady-state error in the observed control signals, along with expected objectives of adequate power sharing and voltage regulation in the system.