Abstract:
Conventional Photovoltaic system use low voltage appliances of 12 or 24
volt rating. Normally available 230VAC, 50Hz lamps, fans and electronics
goods cannot be used in these system. In this thesis, attempt to made to
design and analyze a dc-dc-ac converter to provide a 230VAC at 50 Hz from
PV modules and energy storage batteries used in PV systems. DC converters
are used as DC transformers to step up or step down DC voltages.
Harmonics are generated at the input and load side of the converter, and
these harmonics can be reduced by input and output filter. A Cilk converter
increases and decreases the output voltage. In this thesis work a 12V DC to
300V boost is required. A two stages or cascaded Cilk converter is step up
the DC voltage to 340V from 12V battery. Cascaded Cilk converter is used
for stepping battery voltage up, which can then be converted to AC by a
PWM inverter and filtered to have sinusoidal 230VAC at 50Hz. The output
AC thus obtained can be regulated precisely, either by controlling the duty
cycle of the cascaded Cilk converter or by controlling modulation index of
the PWM inverter. The required 230VAC, 50Hz is obtained by a
conventional single phase PWM inverter followed by low pass LC filter.
The complete circuit has been studied by simulation in this work so as to
obtain the design procedures of an integrated switch mode DC-DC-AC
power converter. The study provides an integrated switching mode
conversion of 12VDC to 230VAC at 50 Hz which will allow conventional
appliances of 50 Hz, 230VAC to be used in domestic photovoltaic system.
