Harmonics on a power system may cause which effects?

Harmonics on a power system may cause which effects?

• A. inefficiency in motors
• B. low total power factor
• C. utility-imposed penalties
• D. all of the above

Answer: (D)

Harmonics distort the voltage and current waveforms in a power system, which leads to several adverse effects. The distorted current increases I^2R losses in motor windings and other equipment, causing heating and reduced efficiency. This same distortion also lowers the overall power factor because the harmonic currents do not contribute to useful real power, even though they add to the apparent power. Utilities monitor harmonic levels and power-factor metrics; if these exceed limits, penalties or charges can be applied to reflect the reduced power quality and potential impact on the grid. Because harmonics can cause all of these problems, the correct choice is all of the above.

Harmonics distort the voltage and current waveforms in a power system, which leads to several adverse effects. The distorted current increases I^2R losses in motor windings and other equipment, causing heating and reduced efficiency. This same distortion also lowers the overall power factor because the harmonic currents do not contribute to useful real power, even though they add to the apparent power. Utilities monitor harmonic levels and power-factor metrics; if these exceed limits, penalties or charges can be applied to reflect the reduced power quality and potential impact on the grid. Because harmonics can cause all of these problems, the correct choice is all of the above.