MPP Tracking

The Maximum Power Point Tracking (MPPT) function in our electronic loads enables the testing of solar or photovoltaic modules by controlling the maximum power point (MPP) of the connected unit under test by varying the voltage setting in constant voltage mode.

The MPP (Maximum Power Point) is the operating point at which the test object (solar, PV module) delivers maximum power. The last found/controlled MPP can be queried via a data interface.

The function consists of the two sub-functions sweeping and tracking, which constantly alternate at an adjustable interval. If the open-circuit voltage measured at startup is higher than the minimum voltage, the electronic load performs a sweep and then readjusts the global MPP found. The sweep function measures the open-circuit voltage Voc of the DUT, determines the V/I characteristic and, based on this, calculates the global MPP. The sweep direction, sweep duration and sweep period (time interval between two successive sweeps) can be set.

power curve vs. voltage
current curve vs. voltage

The V/I characteristic curve can be read via a data interface. On instruments with a graphical user interface, the V/I and V/P characteristic curve is displayed in the function graph:

MPPT characteristics

When the MPPT function is activated, the energy in Wh is accumulated starting from 0 until the execution is deactivated. If the load input is switched off while MPP tracking is active, the accumulation pauses until the input is active again. The value is held even after deactivating the MPPT function until it is restarted. The energy value is visible at the user interface and can be read via a data interface.