ABSTRACT
This chapter presents a general description of the most relevant aspects to bear in mind when looking at losses in electrical systems related to harmonic currents. The utilization of harmonic cancellation schemes that eliminate higher-order harmonics is also relevant because losses are associated with the square of the current. Increased rms values of current due to harmonic waveform distortion lead to increased heat dissipation in equipment and undesired fuse operation in capacitor banks. For the case of harmonic distortion, the total losses can be expressed as the summation of the individual losses, including every harmonic frequency. Total harmonic distortion factor measures the contribution of the additional rms harmonic current to the nominal rms fundamental current; however, similar to crest factor, it does not have a means to consider harmonic heating losses. In the case of motors supplied from variable frequency drives, elevated levels of harmonics can be involved.
