The electrical characteristics of the TE modules were tested in
steady state and dynamic conditions by using steps of the electric
heat power from 0 to 150 W.
A rheostat was connected to the TE modules as a load, and the
resistance R
set at different values in the range 1–10 U (Fig. 4). The
measured power Po that can be produced by one TE module as
a function of the electric load R
L
is shown in Fig. 5. The temperature
difference (
DT) between the hot side and cold side of the TE module
is about 100
L
C.
In the same figure, we provided the model base power assuming
) of 1.75 U and an
open-circuit voltage (Voc) of 2.65 V for comparison.
for the TE generator an internal resistance (R
int
The comparison between the experimental results and that of
the model permits to validate the experimental procedure.
The variation of the voltage (Vo) and output power (Po) characteristics
for an electric load of 2
U of the TE module as a function
of the temperature difference (
DT) between the hot side and cold
side of the TE module is shown in Fig. 6. Thus, we can verify that the
voltage is proportional to
DT, and the power to DT
.
A fixed resistance (R
L
2
)of2U is used instead of the matched resistance
of 1.75
U because it is obvious that being always at the matched
output is not realistic in a real working system. However, as explained
in [14], knowing the internal resistance makes it easy to determine the
maximum output power using P
max
¼ Vo
2
=4R
Fig. 7. Model of the TE power generator.
int
ð1 þ R
int
=R
L
Þ