The thesis describes a development of simple and low engineering cost Single Cycle Controlled grid connected inverter. The voltage
source current controlled inverter aims to support low voltage grid
from small scale distributed power sources.
Single Cycle Controller uses real time current to control PWM
switching of the inverter. The controller forces output current to
have the same phase as an ordered AC signal. The inverter supports
the grid at unity power factor if the AC signal is taken directly
from the grid. Use of a generated AC signal is proposed, which
allows control over active and reactive current injection or
absorption by the inverter. A new synchronized waveform generation
method implementable in a
microcontroller is proposed in the thesis.
A number of Single Cycle Control switching strategies for the
H-bridge converter are tested. A hybrid pulse width modulation
switching strategy is used as it switches only one switch at high
frequency at any time, which reduces switching losses in the bridge
and allows easier implementation in hardware. The controller
limitation near voltage
zero crossing in boost mode is illustrated.
Single Cycle Control faces results in current distortion near
voltage
zero crossings. Strategies to manage this are presented.
The inverter is simulated in PSCAD and hardware prototype is
built. The prototype results are presented for current injection
into the grid at unity power factor.
| Identifer | oai:union.ndltd.org:canterbury.ac.nz/oai:ir.canterbury.ac.nz:10092/3451 |
| Date | January 2009 |
| Creators | Ghimire, Pramod |
| Publisher | University of Canterbury. Electrical and Computer Engineering |
| Source Sets | University of Canterbury |
| Language | English |
| Detected Language | English |
| Type | Electronic thesis or dissertation, Text |
| Rights | Copyright Pramod Ghimire, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
| Relation | NZCU |
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