NLC Electric Systems Practice Exam 2025 - Free Electric Systems Practice Questions and Study Guide

Harmonics in electrical systems are defined as voltage or current waveforms that have frequencies that are integer multiples of the fundamental frequency. In a typical power system, the fundamental frequency is usually 50 Hz or 60 Hz, depending on the region. Harmonics arise when non-linear loads, such as computers, fluorescent lighting, and variable frequency drives, draw current in a non-linear manner, causing the current waveform to deviate from its ideal sinusoidal shape.

The presence of harmonics can lead to several issues, including overheating of equipment, increased losses in the power system, and disruption of sensitive electronic devices. Therefore, understanding harmonics is crucial for maintaining power quality and ensuring the efficient operation of electrical systems. Highlighting the importance of this concept, harmonics directly relates to the analysis and mitigation of distortion in electrical waveforms, which is essential for electrical engineers and systems operators in designing and maintaining effective electrical networks.