Active Power Factor Controller

A power factor of one or "unity power factor" is the goal of any electric utility company because if the power factor at the load end is less than one, the utility company has to supply more power than required for unity power factor. In doing so the apparant power is lost in the form of heat. In order to compensate this apparant power loss, utility companies levy penalty to the consumers who maintain the power factor less than one.

It is also to be noted that low power factor reduces an electrical system's distribution capacity by increasing loss due to higher current flow and results in voltage drops.

Power factor controller with Harmonic filters: Certain Loads like UPS and Variable frequency drive produce harmfull harmonics which circulate in the electrical system and adds to the neutral current.

As these harmonics cause a lot of problems to loads and transformers and hence have to be mitigated. Harmonic filters in series with capacitors acts as a low impedence path to these harmonic currents and they eliminate or mitigate these harmonics.

It is now mandatory that harmonics are kept within certain levels to avoid penalty by the supplier of power.

Harmonic Filters: Harmonic reduce system efficiency and waste precious energy . Harmonic overheat and overload electric installations , distribution transformers fuses and conductors etc.

They cause premature system ageing or generate the requirement for an increase in system capacity. Harmonics overload capacitor banks in VAR compensation and cause parallel resonance and cause malfunction in electronic controls, disturbances in sensitive medical devices, or crashes in communication networks.

Types of Harmonic filters:
  • Detuned filters in series with Automatic capacitors banks, which acts as harmonic traps.
  • Passive harmonic filters fitted in series with the harmonic load. Suitable for installing with stable loads and filters harmonics at source itself.
  • Active filters: Active Version is ideal for the reliable compensation upto the 50 th harmonic, as well as reactive power , in a targeted manner. With a response time of less than 300 micro seconds. The active filter mitigates harmonics in the neural wire also and triplen harmonics upto the 50th.

The Active filters have the following advantages: Reliability, cost saving , efficiency, fast response time, compact and rugged. Active filters will enable to achieve compliance with international standards like IEEE 519-1992 as well as EN61000-2-3.

For more Info on Harmonics please refer to attachment.