Harmonics and disadvantages

Harmonics are distortions of the sine wave which is provided by the local power company. These distortions are usually produced by electrical equipment that utilizes the family of semiconductors known as thyristors (diodes, SCR’s etc). Harmonics are classified as being even multiples of the 50 or 60 Hertz base frequency, which makes the second harmonic frequency 120Hz and the third 180Hz. The harmonic distortion may involve higher than normal peak voltages and currents which can cause premature failure of devices such as motors, transformers, circuit breakers and switchgear through insulation breakdown, excessive arcing and overheating.

Harmonic Filters

By determining the potential causes of harmonics in the setting, and by examining the facility electrical prints, the proper resistor configuration can be developed. Harmonic filters are the best solution to harmonic distortion. Harmonic filters are only one piece of the power system puzzle. To properly condition the system, more active components such as capacitors and reactors may have to be used as well.

Harmonic Filter Applications

  • HVDC conversion stations
  • Transmission voltage regulation
  • Power quality and transfer increase
  • Reactive power control
  • Voltage stabilization (Wind farm)
  • Dynamic voltage support (Railway)
  • Arc furnaces, rolling mills (Metal)
  • Winders and crushers (Mining Industries)
  • Compressors, pumps and drill
  • Electrical propulsion and diesel systems