The model used for creating the reference voltage is shown
in Fig. 4. First, photovoltaic output current (Ipv) and output
voltage (Vpv) are passed through a first order low pass filter
with a magnitude of G = 1 and a time constant of T = 0.01
seconds in order to filter out the high frequency components
or harmonics from these signals as shown in Fig. 5 and Fig. 6.
The filtered current and voltage signals (Ipv_F and Vpv_F) are
then fed into the MPPT control block that uses the Incremental
Conductance Tracking Algorithm. An algorithm that is based
on the fact the slope of the PV array power curve shown in
Fig. 7 is zero at the Maximum Power Point (MPP), positive on
the left of the MPP, and negative on the right. The MPP can
thus be tracked by comparing the instantaneous conductance
(I/V) to the incremental conductance (∆ I/∆ V) [11] as in (1):