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Idiomas disponibles
Idiomas disponibles
EN
ADVANTAGES OF MPPT VS PWM TECHNOLOGY (CONTINUED)
GAINS OF A MPPT OVER PWM
The voltage of a photovoltaic solar panel varies according to its temperature: its voltage decreases as the
temperature increases and vice versa. This normative value, called the temperature coefficient, is given
with a cell temperature of 25°C.
Example: with a panel that displays +/-0.34%/°C, we must correct the Vmp voltage by -0.34% per cell
degree above 25°C.
As shown in the example below, which highlights voltage variations due to temperature and voltage drops
due to the cable, a UNIMPPT charge regulator allows an APG (Average Production Gain) of 20% in
summer and up to 40% in winter.
In addition, it is noted that the more the battery is discharged and/or the panel voltage is high, the greater
the advantage of an MPPT over a PWM is.
Solar radiation
during the winter
Sunrise
9h
12h
End of charge
16h
Solar radiation
During the summer
Levé du jour
7h
10h
Fin de charge
14h
* Example MPPT efficiency 95%
24/59
100 W solar panel with a UNIMPPT regulator
Solar
Panel
panel
Voltage
temperature
Vmp
5°C
20,0
19,9
19,8
19,7
19,6
15°C
19,5
Solar
Panel
panel
Voltage
temperature
Vmp
30°C
18,4
17,2
17,2
16,6
16,3
70°C
16,0
-Voltage
Voltage
drop due to
battery
the cables
charge
(5%)
19,0
12,2
18,9
12,5
18,8
13,0
18,7
13,5
18,6
14,0
18,5
14,6
-Voltage
Voltage
drop due ti
battery
the cables
charge
(5%)
17,5
12,2
16,3
12,5
16,3
13,0
15,8
13,5
15,5
14,0
15,2
14,6
www.uniteck.fr
Theorical
Theorical
Gain in
gain in
value
%
6,8
56%
6,4
51%
5,8
45%
5,2
39%
4,6
33%
3,9
27%
GPM Moyen
Theorical
Theorical
Gain in
gain in
value
%
5,3
43%
3,8
31%
3,3
26%
2,3
17%
1,5
11%
0,6
4%
GPM Moyen
Gain
rectified
MPPT *
53%
49%
42%
37%
31%
26%
+ 40%
Gain
rectified
MPPT *
41%
29%
24%
16%
10%
4%
+ 20%
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