Effects of harmonics on voltage distortion and losses in wiring

Many loads in modern offices and industrial plants are nonlinear. A common source of harmonic currents in power systems is the electronic equipment that uses a rectifier supplying a d.c.-link with storage or ripple- smoothing capacititors. This type of electronic power supply is used either in factory adjustable-speed drives or in personal computers and home electronics. They create current and voltage distortion. In Slovenia, a.c. mains supply with a frequency of 50 Hz is used. Waveform distortion results from on addition of other frequencies which are multiples of the fundamental frequency. Nonlinear loads usually generate current distortion. Voltage distortion is created by the current flowing in of supply and distribution impedances. Nonlinear loads have a very low power factor in terms of total watts/volt-amps. This means that there is more current flowing in the power system than required to have the job done. Harmonic currents cause power system heating and losses in wiring and transformer.