What is the primary effect of nonlinear loads on electrical systems?

The primary effect of nonlinear loads on electrical systems is the injection of harmonic currents. Nonlinear loads, such as computers, LED lights, variable frequency drives, and other electronic devices, do not draw current uniformly over the entire cycle of the voltage waveform. Instead, they can lead to the distortion of the current waveform, causing harmonics to be present in the electrical system.

Harmonic currents are multiples of the fundamental frequency (typically 60 Hz in North America) and can create various issues, such as overheating of equipment, increased losses in transformers, and interference with sensitive electronic devices. These harmonics can also cause malfunctions in protective relays and create a need for mitigation measures like harmonic filters, which adds to operational costs.

Understanding the effect of harmonic currents is essential for maintaining the efficiency and reliability of electrical systems and ensuring that all equipment operates within its design specifications. This is critical in the context of balancing power quality and ensuring the longevity of the electrical infrastructure.