ASSESSMENT OF HARMONICS AND INTERHARMONIC OF GRID-INTERACTIVE SYSTEMS

Edmund Kwafo Adjei-Saforo

Kumasi Technical University

Misbawu Adam

Kumasi Technical University

Solomon Nchor Akansake

Kwame Nkrumah University of Science and Technology

Samuel Addo Darko

Kumasi Technical University

Keywords: Harmonics, inter-harmonics, inverters, photovoltaic


Abstract

Power quality is at all times an important issue in the area of power systems. With the reconstruction of industrial structure and not-long-ago development of intelligent grid technology, more and more renewable energy is integrated into the power systems that may corruptly abase the power quality transmitted to the end-users. Many modern solid-state devices widely used in a range of applications in these green or renewable energy systems offer economical and reliable solution for effective and efficient control of these systems. Notwithstanding these, they also present nonlinear operational characteristics and introduce voltage and current contamination such as harmonics and inter-harmonics into the power grid . The inter-harmonics produced by converters employed in renewable systems are overlooked by some researchers, but their integral effects are very titanic. In this paper, harmonic and inter-harmonics generated by converters used in photovoltaic and wind turbine are investigated. It analyzes the harmonics and inter-harmonic generated by pulse width Modulation (PWM) modulation, the dead zone effects of semi-conductor switching device - Insulated Gate Bipolar Transistor (IGBT), and the DC voltage fluctuations. This leads to observation that as the number of harmonics increases, the switching frequency increases, which has been verified by theoretical analysis, simulation, and experimental results.


Author Biographies

Edmund Kwafo Adjei-Saforo, Kumasi Technical University

Faculty of Engineering and Technology, Kumasi Technical University

Misbawu Adam, Kumasi Technical University

 Faculty of Engineering and Technology

Solomon Nchor Akansake, Kwame Nkrumah University of Science and Technology

Faculty of Physical Sciences Computational Sciences

Samuel Addo Darko, Kumasi Technical University

Faculty of Engineering and Technology