Deviation from linear summation law for large number of homogeneous led lamps

This work presents measurements on how the emission from a lighting installation, in the frequency range up to 2 kHz, increases with the number of lamps. Measurements are performed on an installation with lamps of the same brand and type. Two indicators are used to quantify the deviation of a linear increase: harmonic deviation factor; aggregation exponent. It is shown experimentally that considering a linear increase of emission with the number of lamps may lead to both underestimation and overestimation of the emission from the whole installation. It is also observed that different individual harmonic orders show different behaviour. The deviation from a linear summation law roughly increases with harmonic order, but even for the highest harmonic orders, a unity aggregation exponent remains an acceptable model for most applications.