The effect of new residential appliances on Power Quality

The changing nature of residential network loads means that Power Quality is becoming a significant issue in New Zealand and internationally. Many residential appliances have electronic power converters that characteristically draw a non-sinusoidal current waveform. This results in increased harmonic voltage levels in the distribution network. The total impact depends on the number of appliances, their power ratings, and their harmonic diversity. A measurement survey has been performed of different categories of modern appliances to determine their Power Quality characteristics. In addition, computer modelling of the appliances on a typical distribution feeder shows their relative harmonic voltage impact.