Abstract:
Single phase diode rectifiers are widely used in industrial, commercial, utility and
domestic applications. Many input wave shaping methods have been proposed to
solve the problem of poor power factor which can be classified as active and
passive methods. Six different DC-DC converter topologies have been studied to
solve the low efficiency, poor input power factor and total harmonic distortion
problems of single phase AC-DC converters. The proposed topologies showed
superior performance over passive filtering techniques and output regulated
single phase AC-DC converters. Some of the input switched topologies have
been reported earlier, whereas, new input switched topologies with reduced
component number are proposed in this thesis. Five reduced component input
switched single phase AC-DC rectifier has been studied. The topologies used are
Boost configuration-2, Buck-Boost configuration-3, Ćuk configuration-2, SEPIC
configuration-2 and Inverse SEPIC configuration-2. Results are compared with
the reported ones. Proposed topologies show lower input current THD, higher PF
compared to previously reported topologies. However efficiency remains almost
the same for both previous and proposed topologies. All the newly reported
topologies are easier to implement. Typical output voltage and input current
waveforms are shown. It has been found that without feedback control, the input
switched single phase rectifiers perform better than output regulated single phase
AC-DC converters in terms of input current THD, input power factor and
conversion efficiency. Input switched single phase AC-DC converters reported
earlier and proposed in this thesis are expected to perform better with feedback
control circuit as well. As an example an input switched Boost regulated single
phase AC-DC converter is studied and its performance is briefly compared with
output regulated Boost single phase AC-DC converter.
