Influence of small Constant-Power-Loads on the power supply system of an aircraft

Today most electrical consumers in an aircraft grid are electronic loads. Compared to resistive or motoric loads these loads have constant power consumption, which is independent of the supply voltage. This characteristic may have a negative effect on the stability of a power supply system. In addition real Constant-Power-Loads can have some other peculiarities. Depending of the topology or the supplied voltage type (AC or DC) the dynamic characteristic differs. This paper deals with a characterization of 4 types of Constant-Power-Loads in an actual and future aircraft grid. The investigations are focused to the dynamic characterization of different loads. Theoretical investigations are combined with measurements in an artificial aircraft grid with realistic supply voltage variations.