What does the term "harmonic distortion" refer to in electrical systems?

Harmonic distortion in electrical systems refers to the presence of frequencies that distort the normal wave shape of electrical signals, specifically the sinusoidal waveform that is typically generated by AC sources. This distortion is caused by non-linear loads, such as computers, fluorescent lighting, and other electronic devices, which draw current in a way that creates additional frequencies (harmonics) that are multiples of the fundamental frequency.

These harmonics can interfere with the performance of electrical equipment, degrade the quality of power delivery, and result in overheating or other issues in electrical components. Understanding harmonic distortion is crucial for maintaining system efficiency and reliability, as excessive distortion can lead to poor power quality and can require corrective measures, such as the installation of filters or the use of more robust equipment designed to handle such distortions.

The other choices discuss unrelated concepts: increasing voltage in transmission lines involves different technologies such as transformers, temperature fluctuations concern thermal management of electrical components, and the type of load refers more to the nature of the devices connected to the system rather than to distortion of waveforms.