AGI-FLL Control for Pico-Hydro Based Microgrid with Seamless Connection to Utility/DG Set

Abstract

This work presents a pico-hydro based microgrid (MG) to supply nonlinear loads. It is capable of connecting with the utility or a diesel generator (DG) set. If utility is available and load requirement is less, the power is fed to the utility. The system functions in multimode, if renewable power generation is not adequate at the grid outage, then the system is connected to the DG (Diesel Generator) set to fulfill the requirement of loads. Therefore, to provide uninterrupted power to loads and smooth switching, a robust AGI-FLL (Advanced Generalized Integrator Frequency Locked Loop) is comprehended. In off-grid mode, the AGI-FLL control provides the voltage and frequency regulation for realizing the reliable functioning of MG. In utility connected mode, the VSC (Voltage Source Converter) functions in the current control mode. As only one VSC is utilized, thus reducing the complexity and cost of the implemented system. Moreover, to assess the effectiveness and flexibility of the implemented approach, three phase four wire microgrid is simulated. The response of the AGI-FLL control technique is carried out in MATLAB 15b/Simulink platform. The acquired results validate that AGI-FLL control enhances the power quality and provides required reactive power and neutral current compensation. Additionally, it corrects the mismatch between generation and consumption even during changes in load consumption.