22-09-2012, 11:25 AM
Single-Phase AC–AC Converter Based on Quasi-Z-Source Topology
ABSTRACT
A Solid State AC/AC Converters converts on AC waveform such as main supply to another AC waveform.
CONVERTERS : 1) Converters with DC link.
2) Cycloconverter.
3) Hybrid matrix Converter
4) matrix Converters.
AC-DC-AC and matrix converters Provide variable output voltage and variable frequency.
Applications: Voltage regulation.
PWM AC-AC Converters used to perform as AC choppers.
Applications: For a better power quality, efficiency, low harmonic current in line, single stage conversion, simple topology. AC/AC Converters also perform Conditioning, Isolating, and Filtering of input power.
The Direct PWM AC/AC Converters Derived from the DC-DC topology. Where all unidirectional switches substituted by bidirectional switches.
Converters are in two modes: AC & DC.
In AC Converters implemented in both single phase and three phase system.
Traditional Conventional System:
To obtain the output voltage direct PWM AC/AC Converters are implemented AC-thyristor controllers, which use phase angle of ac supply.
Dis advantages : High THD(Total Harmonic Distortion),low input power factor.
Advantages of proposed system : Buck-Boost voltage, Reversing or maintain phase angle, low thd, high input power factor.