Description

• An inductor, also called a coil, choke or reactor, is a passive two-terminal electrical component that stores energy in a magnetic fieldwhen electric current flows through it.An inductor typically consists of an insulated wire wound into a coil around a core.
• Inductors are used extensively in analog circuits and signal processing. Applications range from the use of large inductors in power supplies, which in conjunction with filter capacitors remove ripple which is a multiple of the mains frequency (or the switching frequency for switched-mode power supplies) from the direct current output, to the small inductance of the ferrite bead or torus installed around a cable to prevent radio frequency interference from being transmitted down the wire. Inductors are used as the energy storage device in many switched-mode power supplies to produce DC current. The inductor supplies energy to the circuit to keep current flowing during the “off” switching periods and enables topographies where the output voltage is higher than the input voltage.
• Band-pass filters, which are used to filter lowest order harmonics such as 5th, 7th, 11th, 13th. Band-pass filters can be tuned at a single frequency (single-tuned filter) or at two frequencies (double-tuned filter).
• The Three-Phase Harmonic Filter is built of RLC elements. The resistance, inductance, and capacitance values are determined from the filter type and from the following parameters:
  • Reactive power at nominal voltage
  • Tuning frequencies
  • Quality factor. The quality factor is a measure of the sharpness of the tuning frequency. It is determined by the resistance value.