Abstract :
Many commercial systems are private 400 V supplies. A large number of distorting loads have been connected at these sites with the result that the source current waveform may be distorted. Consequently, excessive harmonic voltages may be generated. Other commercial supplies may be connected to systems which contain excessive distortion. This problem is likely to occur when an office is installed within the confines of a larger private supply. In either case the level of harmonic distortion may be sufficiently high to cause problems and this prospect should be considered at the planning stage. Commercial systems contain many of the features of a larger system but at a different scale. This means that the relative importance of the different elements of the supply is different to their importance to a larger power network. Many of the distorting loads found in commercial systems are small in size but there are many such loads contributing to the total distortion, These factors and others are considered in the paper
