User Manual

4
Input power (P
PV
)= Output power (P
Bat
)
Input voltage (V
Mpp
) *input current (I
PV
) =Battery voltage (V
Bat
) *battery current (I
Bat
)
Normally, the V
Mpp
is always higher than V
Bat
, Due to the principle of conservation
of energy, the I
Bat
is always higher than I
PV
. The greater the discrepancy between
V
Mpp
&V
Bat,
the greater the discrepancy between I
PV
& I
Bat
. The greater the
discrepancy between array and battery, the bigger reduction of the conversion
efficiency of the system, thus the controller‘s conversion efficiency is particularly
important in the PV system.
Figure 1-2 is the maximum power point curve, the shaded area is charging range
of traditional solar charge controller (PWM Charging Mode), it can obviously
diagnose that the MPPT mode can improve the usage of the solar energy
resource. According to our test, the MPPT controller can raise 20%-30%
efficiency compared to the PWM controller. (Value may be fluctuant due to the
influence of the ambient circumstance and energy loss.)
In actual application, as shading from cloud, tree and snow, the panel maybe
appear Multi-MPP, but in actually there is only one real Maximum Power Point. As
the below Figure 1-3 shows:
Figure 1-2 Maximum Power Point Curve