| PhD Viva

Name of the Speaker: Mr. Lokesh N (EE17D006)
Guide: Prof. Mahesh Kumar
Online meeting link: https://meet.google.com/ims-xuao-jjz
Date/Time: 14th June 2024 (Friday), 3:00 PM
Title: An Improved Sliding Mode Control Scheme for Power Quality Conditioners in Distribution System.

Abstract :

Distributed generation (DG) is a constantly evolving trend that connects renewable energy sources (RES) like solar and wind to the utility grid, in addition to the conventional energy sources like coal, oil, and gas. The widespread use of RESs and the power-switching electronics devices at the industrial and residential levels create power quality (PQ) issues. The custom power devices (CPD) were developed at the distribution system as a result of the severe regulations imposed on DG systems and the consumer demand for better PQ. To enhance the performance of CPDs, the improvement contributed to the conventional sliding mode control scheme will be presented in this talk considering CPD under various grid conditions and converter configurations.

The thesis presents (i) the performance comparison of various phase-locked loops (PLLs) for accurate extraction of phase angle of grid voltage. (ii) While developing a conventional sliding mode control scheme for four-leg voltage source inverter based systems in the natural reference frame, it has been analytically demonstrated that the conventional scheme encounters challenges in generating switching pulses. This difficulty arises due to the coupling of dynamics in the sliding variable on each phase through all phase pole voltages. To address this, a new sliding surface is proposed in this thesis. (iii) Further, to validate the proposed concept, simulation and/or experimental studies conducted on various CPDs are presented. The CPDs considered are four-wire distribution static compensator (DSTATCOM), four-wire dynamic voltage restorer (DVR), and four-wire dual-output converter based unified power quality conditioner (UPQC).