Schneider Electric Owner's Guide

Maximum Power Point Tracking
975-0560-01-01 G 1–3
Maximum Power Point Tracking
Maximum Power Point Tracking (MPPT), allows the charge controller to harvest
the maximum energy available from the PV array and deliver it to the batteries.
The MPPT algorithm continuously adjusts the operating voltage of the array to
find the maximum power point. Input power is measured and compared to the
amount of input power harvested at the previous operating voltage. The next
adjustment to the operating voltage is dependent upon whether the charge
controller harvested more or less power than it did at the previous operating
voltage.
The algorithm is implemented by applying a variable load on the array—shown
by the power curve (solid line) in Figure 1-1—until it finds the peak power (the
point at which the combination of the operating voltage and current is
maximized), as indicated by MPP in Figure 1-1. The charge controller will
continue adjusting the operating voltage to stay on the maximum power point.
This is necessary as MPP changes throughout the day due to panel temperature,
panel shading, and sunlight intensity. The adjustments happen without
interruption of output power flow to the batteries.
Fast Sweep™ Shade Tolerant MPPT Algorithm
The charge controller has a Fast Sweep MPPT algorithm that frequently conducts
a very fast sweep of the full operational array voltage window to dynamically
determine the array’s maximum power point. This feature optimizes the high
energy harvest of the solar array., regardless of conditions such as temperature
and shading. For more information on shade-tolerant MPPT optimization, visit
solar.schneider-electric.com/solar.
Figure 1-1 Maximum Power Point Curve
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975-0560-01-01(XW-MPPT80-600_Ops).book Page 3 Wednesday, November 22, 2017 5:52 PM