Sunny Boy 700
Technical Description
SB700-11:EE
-
73
-
SMA Regelsysteme GmbH
Minimum MPP voltage of the PV panel
If the temperature of the PV cells is very high the MPP voltage of the PV panel de-
creases. If there is a fixed lower limit of the MPP voltage on the inverter it is not pos-
sible to feed the maximum available PV panel power to the low-voltage electricity
grid. The inverter stays at the lower input voltage limit and cannot follow the MPP of
the PV panel any more. Therefore the Sunny Boy has got a flexible MPP voltage
range.
There is a fixed ratio of the minimum MPP voltage V
MPPmin
from the Sunny Boy to the
PV panel and the grid voltage V
AC
as shown in Fig. 9.1.The minimum DC voltage is
determined according to the current grid voltage. The flexible MPP voltage range
allows for optimum utilization of the inverter’s characteristics and a higher power
yield.
90
95
100
105
110
115
120
125
130
185
190
195
200
205
210
215
220
225
230
235
240
245
250
255
260
265
Vac [V]
Vm
pp mi
n
[
V
]
100 V DC
126 V DC
198 V AC
251 V AC
230 V AC
116 V DC
Fig. 9.1: Minimum MPP voltage of the Sunny Boy 700 in the
input voltage range of 125 V – 250 V DC