A Hysteresis Compensation Algorithm for the Generation of Nonlinear Voltage Sweep for IV-Characteristic Measurement of High-Capacitance Solar Modules With Xenon Flasher

Short measurement time of tens of ms at industrial production leads to high influence of parasitic current on the current voltage (
IV
) curve characterization. This parasitic current deteriorates the measurement accuracy and should be mitigated. However, most methods, like, e.g., sectional measurement or DragonBack
^TM
, are based on either unpractical long measurement time or sophisticated simulations. We present an algorithm for the generation of voltage sweep for low hysteresis measurement of
IV
characteristics in high capacitive solar modules. Using one linear voltage sweep-based
IV
characteristics as input, an optimized nonlinear voltage sweep is generated with our algorithm. While the linear voltage ramp during a 93 ms pulse leads to a hysteresis error at maximum power (ϵ
_Pmpp
) of 1.46% for a 1-cell heterojunction minimodule and 2.35% for a 120-cells heterojunction solar module, the ϵ
_Pmpp
with the optimized nonlinear voltage ramp is reduced to 0.38% and 0.48%, respectively. The hysteresis error of short-circuit current (ϵ
_Isc
) and hysteresis error of open-circuit voltage (ϵ
_Voc
) remain below 0.5% by optimized nonlinear voltage ramp. Thus, all three hysteresis error parameters ϵ
_Pmpp
, ϵ
_Isc
, and ϵ
_Voc
fulfill the standard IEC 60904-1 (edition-3).