Assessment of Harmonic Distortion in Power Distribution Systems Serving University Campuses in Zaria, Kaduna State

This study assesses harmonic distortion levels in the power distribution systems supplying Ahmadu Bello University, Zaria, Kaduna State, North West Nigeria. University campuses host a high density of non-linear loads including computer laboratories, variable speed drives, UPS systems, fluorescent and LED lighting fixtures, and laboratory equipment, all of which inject harmonic currents into the distribution network and cause voltage waveform distortion. Field measurements were taken at 15 representative load points spanning academic blocks, laboratories, hostels, and administrative buildings using a Fluke 435 Series II power quality analyser over a two-week period covering weekday and weekend loading patterns. Total harmonic distortion of voltage and current, individual harmonic orders up to the 50th, and power factor were recorded at each point. Results indicate that voltage THD exceeds the IEEE 519 limit of 5 percent at six of the 15 measurement points, with the computer laboratories and server rooms recording the highest values of 9.8 and 11.4 percent respectively. The 3rd, 5th, and 7th harmonic orders dominate the current spectrum at all locations. Power factor averages 0.78 across the campus, indicating a significant reactive power burden on the campus substation. Neutral conductor overloading is identified as a secondary consequence of high 3rd harmonic triplen currents. The study recommends installation of passive low-pass filters at the computer laboratory distribution boards and upgrades to K-rated transformers in high-harmonic-load areas. Keywords: harmonic distortion, power quality, university campus, IEEE 519, Zaria.