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 power capacitor units in Northern Taiwan. Through one year of measurements, about 12,000 sets of harmonic voltage and current data were recorded and analyzed. The types and levels of harmonics are shown 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 the background level of harmonic voltages with 95% cumulative probability which is adopted by Taipower. In conclusion, the effects of harmonics on capacitors and power transformers are discussed.