TITLE:
Study and Design of a DC/AC Energy Converter for PV System Connected to the Grid Using Harmonic Selected Eliminated (HSE) Approach
AUTHORS:
Dominique Bonkoungou, Éric Korsaga, Toussaint Guingané, Sosthène Tassembédo, Zacharie Koalaga, François Zougmoré
KEYWORDS:
Inverter, Modulation Index, Transistors, Power Stage, Harmonic Selective Eliminated, Photovoltaic (PV) System
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.12 No.3,
March
18,
2022
ABSTRACT: Nowadays,
distributing network-connected photovoltaic (PV) systems are expanded by
merging a PV system and a Direct Current (DC)/Alternating Current (AC) energy
converter. DC/AC conversion of PV energy is in great demand for AC
applications. The supply of electrical machines and transfer energy to the
distribution network is a typical case. In this work, we study and design a
DC/AC energy converter using harmonic selective eliminated (HSE) method. To
this end, we have combined two power stages connected in derivation. Each power
stage is constituted of transistors and transformers. The connection by
switching of the two rectangular waves, delivered by each of the stages, makes
it possible to create a quasi-sinusoidal output voltage of the inverter.
Mathematical equations based on the current-voltage characteristics of the
inverter have been developed. The simulation model was validated using
experimental data from a 25.2 kWp grid-coupled (PV) system, connected to
Gridfit type inverters. The data were exported and implemented in programming
software. A good agreement was observed and this shows all the robustness and
the technical performances of the energy converter device. It emerges from this
analysis that the inverter output voltage and the phase angle thus simulated
are very important to control in order to orientate the transfer of the power
flow from the continuous cell to cell to the alternating part. Simulated and
field-testing results also show that increases in the value of the modulation factor
(m) for low power output are highly significant. This study is an important
tool for DC/AC inverter designers during initial planning stages. A short
presentation of the design model of the inverter has been proposed in this
article.