Harmonics-what are they, how to measure them and how to solve the problem (in connection with standards IEEE 1159-1995 and IEEE 519-1992)

To express a deviation from a pure sine wave usually the term harmonics components is used. In electricity harmonics are described as follows (IEEE 1159-1995): "Harmonics are sinusoidal voltages or currents having frequencies that are integer multiples of the frequency at which the supply system is designed to operate". The multiples are integer multiples of the basic (fundamental) frequency 50 Hz. The author discusses the reasons why harmonics in power systems should be considered seriously. The author briefly discusses seven definitions from IEEE 519-1992 that are of importance. The author then discusses who produces harmonics, how they are monitored and how to solve the problems caused by harmonics.