PCC Voltage Quality Restoration Strategy of an Isolated Microgrid Based on Adjustable Step Adaptive Control

Abstract

Autonomous microgrids supply power to large remote areas, where access to the grid is infeasible. The generation of these microgrids is highly dominated by renewable energy sources equipped with a storage battery. Due to the uncertainty associated with the renewables, the sustainability and reliability of supply become the prime areas of focus. The battery reduces the uncertainty during demand rise, power deficiency, and overloading with their faster response than diesel generators and microturbines. In this article, the power generation of the isolated microgrid is considered from solar and wind energy sources along with a battery. As the load decreases/increases suddenly, the point of common coupling (PCC) voltages are disturbed. So, as a remedy, a new control strategy for enhancing the voltage profile at PCC is introduced here. The improved adjustable step continuous norm adaptive control strategy filters the constituent of the load current, providing enhanced power quality and assurance of the system reliability in feeding sensitive loads. The intelligently controlled proportional integral controller enhances the speed regulation of the synchronous generator, whereas the enhanced perturb and observe technique provides the effective wind maximum power point (MPP) tracking. The load side power converter regulates the dc-link voltage and the boost converter allows the extraction of solar MPP. The batteries are deployed as the residential storage systems for backing up the power firming renewable production. Moreover, it optimizes the power flow and operation of the microgrid. It provides the required power based on fluctuating load demand. The performance improvement obtained on a laboratory developed test setup verifies the microgrid effectiveness under renewable generation variability and load alterations.