Survey of harmonic voltage and current at distribution substation in Northern Taiwan

This paper presents a survey of voltage and current harmonic distortion levels at 40 power transformers and 10 capacitor units in Northern Taiwan. Through one year measurement, about 12,000 sets of harmonic voltage and current data are recorded and analyzed. The types and levels of harmonics are showed in each power transformer which supplies different residential, commercial, and industrial customers with various loads. At the same time, a suggestion is given to the representative value of background level of harmonic voltages with 95% cumulative probability which is adopted by Taipower. At last, effects of harmonics on capacitors and power transformers are discussed. Keywords: harmonics, distribution substation, survey, electric power quality.