| PhD Viva

Name of the Speaker: Mr. Nitheesh R (EE19D026)
Guide: Prof. Lakshminarasamma N
Co-Guide: Dr. Arun Karuppaswamy B
Online meeting link: https://meet.google.com/vsh-hjcx-ezu
Date/Time: 4th October 2024 (Friday), 3:00 PM
Title: Real-Time Modeling, Design, and Implementation of Power Electronic Converters for Renewable Energy Applications

Abstract :

The research work investigates a power electronic system used for renewable energy applications with a DC-DC converter in the first stage and a DC-AC converter in the second stage. The research is divided into three works. The first work delves into designing and implementing a novel real-time testing platform for power electronic applications using the proposed elemental blocks. The efficacy and accuracy of the proposed work are demonstrated through validation tests conducted on various circuits, including the RL circuit, buck converter, SRDAB, and GCI. Furthermore, real-time data is corroborated with MATLAB, along with results from hardware experimental setups.

The next work is the high gain DC-DC converter, known as the boost full bridge-based dual bridge series resonant converter (BFB-DBSRC), which is a modified version of the DBSRC. It has been designed to elevate low voltage DC to high voltage DC. For stability and performance analysis, the converter has been modeled. The derived small-signal model is validated through time-domain simulation, and the hardware frequency response characteristics are plotted using SFRA. A comparison of the frequency response characteristics is made. An experimental setup with an input voltage of 80 V DC and an output voltage of 800 V DC of 1.5 kW is made to verify the hardware with bidirectional power flow operation of the proposed topology.

The third study introduced a novel converter topology based on DAB that utilizes a pole point inductor to double the input voltage. The proposed pole point inductor-based DAB (PPI-DAB) topology is compared with three similar topologies, highlighting the need for the new topology due to the large and costly capacitor bank in the others. Averaged and small-signal models are derived. The study identified the issue of DC bias current, which leads to problems such as magnetic saturation in the transformer and potential failure of the converter system. To mitigate this, a control method to eliminate the DC bias current is proposed, called the unison duty-phase peak current control. This control algorithm is simulated on PLECS for the PPI-DAB topology. Furthermore, a hardware experiment is conducted using a 1.5 kW system with an input voltage of 80 V and an output voltage of 800 V of 1.5 kW to verify the effectiveness of the topology and control algorithm.