Protection of the Neutral Conductor
Protection of the neutral conductor in three (3) phase systems needs to be given importance during design, particularly on reduced neutral conductor size and when the presence of harmonics is …
Common Mode Voltages: Causes, Effects and Mitigation
Common-mode voltages are a common phenomenon when variable speed drives (VSD) are employed to control motors. There are many advantages of using VSDs in motors. Speed/torque control, and power consumption …
Cable Rating Reduction Factor due to Harmonic Currents
The presence of harmonic current in a power system increases the current in the neutral conductor due to phase current imbalance (refer to Fig. 1b). To ascertain that the current-carrying …
Harmonics and Neutral Currents
Before the advent of computers, variable speed drives, soft starters and other non-linear loads, the only source of harmonics in power systems are industrial plants using arc-furnaces. These arc-furnaces require …
What is the Allowable Harmonics In the Philippines?
I have written several articles about the effects of harmonics and its mitigation. Another question that may pop up is, what is the allowable harmonic content at the point of …
Transformer K-factor Rating and Variable Speed Drives
In this article, I have discussed the difference between a conventional transformer and a K-factor rated transformer. In modern-day plants, Variable Speed Drives (VSD) are widely used. The project I …