ÇUKUROVA UNIVERSITY INSTITUTE OF NATURAL AND APPLIED ...

4. MODELING OF PROPOSED DVR Mustafa İNCİ
4.2.3. Design of DC-DC Converter
This topics presents the controller design procedures of the full bridge
isolated dc/dc converter used in proposed DVR. Figure 4.8 shows the structure of
proposed dc-dc converter.
Figure 4.8. Circuit diagram of full bridge DC–DC Converter
The main function of the dc-to-dc converter is to maintain and control the dc
voltage of the inverter during voltage sag. Proposed DC-DC converter allows the
DVR to compensate deep and long duration voltage sags(Jowder et al., 2009).
Timing diagram with basic operating waveforms are presented in Figure 4.9.
Gate signals (S1, S2, S3 and S4) are generated with comparison of reference signal
with carrier.
Primary switches, S1-S4, are hard switched and operated in pairs, S1-S2 and
S3-S4 respectively. Drive signals are 180 degree phase shifted. Switch transistor duty
cycle, D, is below 50 percent to avoid switch overlap and thus short circuit of input
(Nymand et al., 2010).
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