Electric voltages and currents that can cause power quality issues on an electric power system are called harmonics. It can be produced by electronic devices with nonlinear loads drawing current in sudden short pulses. They are prevalent when multiple computers, printers, fax machines, copiers, UPSs, variable speed drives, etc., are all on the same electrical system. Harmonics specifically lowers the power quality and its efficiency in a commercial building or industrial facility. Overloading neutral conductors, overheating transformers and increased associated losses, and nuisance tripping of circuit breakers are some common problems caused by harmonics. The various studies that are constantly contributing towards advancing technologies and evolution of this field are examined in detail. This book elucidates the concepts and innovative models around prospective developments with respect to this field. A number of latest researches have been included herein to keep the readers up-to-date with the global concepts in this area of study.