Design and Implementation of a Three-Phase Inverter Operated with different Conduction Modes with Automatic Powerfactor Improvement

Abstract

Three phase inverters are widely used to control
different industrial process. Power electronics based inverters are
very popular for fast response and precise control. In this paper
an IGBT based three phase power inverter is proposed.
Conventional three different conduction modes of 1200
, 1500 and 1800 have been adopted. Micro-controller based firing pulse generation circuit using a special multi-winding transformer and opt-coupler to apply isolated firing pulses for each IGBT has
been developed and tested successfully. Simulation and test
results of the inverter for three phase resistive as well as inductive
loads have been presented. The test results are found to be in
good agreement with the simulation outcome and also with the
theoretical analysis. The main objective is to make an inverter
with selectable conduction modes so that specific mode can be
defined for resistive or reactive loads. The required correction for
PFI is done by adjusting the percentage of duty cycle firing pulse
of IGBT to control the capacitive current. The result of the
experiment can be used to design PFI (Power Factor
Improvement) units for the small industries and domestic users
as well. In this paper a three phase inverter of multiple
conduction mode with a switching capacitor power factor
improvement (PFI) system is analyzed