Electronic devices have a nonlinear characteristic and emit harmonics into the low voltage grid. Due to the mass-use of this equipment (consumer electronics, lamps with electronic ballast and so on) the harmonic levels in the grid are usually dominated by the emission of those devices. A lot of harmonic studies are available, which analyze their impact on the harmonic levels based on different types of harmonic models. One commonly used model is the constant current source. Measurements have shown that the harmonic currents emitted
by electronic devices significantly depend on the used circuit topology and the existing supply voltage distortion. The paper quantifies the impact of supply voltage distortion on the harmonic current emission of individual devices and the summation of multiple devices.
After a classification of the commonly used circuit topologies for each of them a model is developed. Based on a comprehensive simulation framework, the individual and combined impact of the most important voltage harmonics (3rd, 5th, 7th) on the harmonic current emission of the modeled devices is analyzed by
a probabilistic study. Based on the results the accuracy of constant current source models is evaluated. Finally the impact of voltage distortion on the summation of multiple devices is analyzed and the accuracy of summation studies based on the measurements of individual equipment is assessed