Q´HARM-a harmonic power-flow program for small power systems

The salient features of a harmonic power-flow program called Q´HARM, are described. Two kinds of harmonic-producing components, the line-commutated six-pulse bridge rectifier and the gaseous discharge lighting load supplied from nonsinusoidal sources, are accurately modelled in this program. Case studies involving the use of Q´HARM for a small power system including converters and gaseous discharge lamps are described. The results include the effect of filters and the computed values of telephone influence indices. It is also shown that the maximum values of telephone influence indices for the different harmonics occur at different points on any transmission line in the system.<>