International Journal of Engineering and Technology

Basically neutral currents are absent in a balanced 3-phase system. However, in the presence of harmonics, neutral currents are naturally flowing. These harmonic-rich currents have been known to negatively affect the current carrying capability or ampacity of the neutral conductor. The effect can be due to two factors. One is due to the magnitude of the harmonic neutral current itself and the other is due to the presence of high frequencies in the current. It has been shown that neutral current magnitude has a direct relationship with content of harmonics in the phase currents. High frequency currents, on the other hand, lead to derating of cable ampacity. This paper study the effect on sizing of neutral conductor due to both factors. The study was done based on several available methods using simulated data.