| PhD Viva

Name of the Speaker: Mr. Tony Thomas (EE21D052)
Guide: Prof. Mahesh Kumar
Online meeting link: https://meet.google.com/dkj-nyxu-med
Date/Time: 27th December 2024 (Friday), 3:30 PM
Title: Operation and Control of PV-Wind based DC Microgrid with Hybrid Energy Storage System

Abstract :

Distributed energy sources play an immense role in the present energy world in providing electrification in remote areas. Among the various distributed energy sources, a hybrid combination of solar and wind has been extensively used. The intermittent and stochastic nature of these renewables make the storage system compulsory for providing reliable power to the load. A combination of batteries and supercapacitors as hybrid storage makes a good choice due to the high energy density of batteries and the high power density of supercapacitors. The first work, utilizes an enhanced exponential reaching law based sliding mode control for extraction of maximum power in the wind energy conversion system. This control law provides faster dynamic response with excellent current tracking and reduced chattering while ensuring MPPT operation. A control method based on the Lyapunov function, ensuring global asymptotic stability is implemented for the bidirectional converters of battery and supercapacitor. The implemented control scheme maintains the DC link voltage constant during solar, wind, and load variations.

The incremental negative impedance feature of constant power loads in the DC microgrid may destabilize the system and its significant presence might affect the dynamics of power electronic converters. The second work presents the control scheme for a PV-wind-hybrid energy storage system based standalone DC microgrid with constant power loads. A control scheme based on super-twisting control and modified super-twisting observer is proposed for the bidirectional converters of battery and supercapacitor. The implemented control scheme provides wider stability margin, better dynamic performance, and tightly regulates the DC bus voltage. The relevant theoretical analyses and the performance of the control algorithms by simulation and experimental studies are presented. The third study develops a power management strategy using an observer-based control scheme for a grid-interactive microgrid. The algorithm determines the system’s operational mode and makes decisions based on the estimated disturbance value. The state of charge of the battery and supercapacitor is kept within their designated limits, and the performance of the power management strategy for charging, discharging, and grid connected operation is verified.