Dc dc converters

1. S.Gomathy M.E.,M.B.AS.Gomathy M.E.,M.B.A
DC-DC converters
S.Gomathy M.E.,M.B.A
Assistant Professor
Department of EEE
Kongu Engineering College

2. S.Gomathy M.E.,M.B.A
✓ DC to DC converters are used for converting one level of DC voltage
(usually raw, unregulated or un-controlled voltage level) to another level of
DC voltage (regulated or controlled voltage level).
✓ Other than converting unregulated voltage level to regulated voltage level,
the DC to DC converters are also used for converting one level of voltage
to other level (higher or lower level).
✓ For instance, a PV system may be designed to give 24 volt but when we
want to convert the DC power to AC power with output voltage of 230 V
(device is called inverter), then the input voltage requirement to the inverter
is high.
✓ These converters play a vital role in PV systems where they are used as
charge controllers, maximum power point trackers and for interfacing the
PV source with different types of loads.
✓ The DC to DC circuits are also used for noise isolation, power bus
regulation and current boosting.

3. S.Gomathy M.E.,M.B.A
✓In DC to DC converter, both input side and output side work on DC power, i.e.,
DC current flows at input side and DC current flows at output side.
✓If we know the current and voltage at the input side we can find out the DC
power feed at input side.
✓Similarly, if we know the current and voltage at the output side, we can
calculate the DC power at the output side.
✓Once we know the DC power at the input side and DC power at the output side,
we can calculate the efficiency of the DC to DC converters.

4. S.Gomathy M.E.,M.B.A
• For a DC to DC converter as shown in Figure 8.9, a battery of 25 V is
connected and the input current is 4 A. At the output side, a voltmeter
shows 50 V across the load and the output current is 1.8 A. Find
(i) Power input to the converter
(ii) Power output by the converter or absorbed by load
(iii) Power lost in the converter due to losses
(iv) Efficiency of the converter.

5. S.Gomathy M.E.,M.B.A