The Harmonic Sources in Electrical Power Systems Analysis & Classification
Dr. Eng. Ihsan Mohammad Motee Bwadekji
The primary cause of harmonic problems in electrical power systems is the massive increase in non-linear loads resulting from technological advancement, such as the use of power electronic circuits and equipment, particularly in AC-to-DC conversion and interfacing stages, or in loads powered by energy systems and utilizing electronic components or microprocessor-supported controllers. These devices generate harmonics due to the loads passing through power systems. Before the advent of power semiconductors, the main sources of waveform distortion were the presence of electric arc furnaces, the cumulative effect of fluorescent lamps, and the limited deployment of transformers and electrical machines. In general, harmonics are emitted by the following equipment: * Converters * Devices which include semi-conductor elements * Generators * Motors * Transformers * Lighting equipment working by gas discharge principle * Photovoltaic systems * Computers * Electronic ballasts * Uninterruptible power supplies (UPS) * Switching power supplies * Welding machines * Control circuits * Frequency converters * Static VAR compensators * Dynamic VAR compensators * Arc furnaces * HVDC transmission systems * Electrical communication systems