DISTRIBUTION FEEDERS WITH NONLINEAR LOADS IN THE NORTHEAST USA .1. VOLTAGE DISTORTION FORECAST

This paper forecasts the level of voltage Total Harmonic Distortion (VTHD) for a typical customer during the next two decades. The study is based on a growth projection of residential, commercial and industrial loads and the acceptance of new technologies such as Adjustable Speed Drives (ASDs) and Electronic Ballasts. The forecast was generated for the service areas of the above two utilities and applied to three real-life, 13.8 kV feeders. The harmonic power flow was determined for each feeder under the assumption of different levels of current distortions and different types of non-lineal: loads. it was found that short feeders, <3 mi, are more immune to harmonic current effects than long feeders, >5mi. It was found that the rate of increase of VTHD could be as low as 0.01%/year for a short feeder without parallel reasonances or could be as high as 0.35%/year in harmonic sensitive systems.