PASSIVE FILTERS FOR HARMONICS
PHF – LIF
PHF
The PHF series Esscom passive filters are characterized by a high capacity to attenuate harmonic disturbances and are designed to be applied in systems where current harmonic distortion must be reduced within defined limits. The use of passive filters contributes to reduce the thermal and electrical overload caused by harmonic currents in installations that include variable speed motor drives, UPS, power rectifiers and other non-linear three-phase loads.
LIF
Esscom LIF series Line Reactors are used to reduce the harmonic content in the current injected into the grid by the soft starter or drive (VFD/VSD), which may interfere with another starter or device connected to the same power supply line. They also protect the starter or drive from transient overvoltages, especially when the power supply comes from a low-impedance network.
Passive Filters (PHF) are additional filters usually installed on the power supply line of the drive.
The filters consist of a combination of inductor (filter inductor) -capacitor inserted in derivation from an asymmetrical series inductor (main inductor). The performance of the passive harmonic filters Esscom PHF series are very high: they reduce the harmonic distortion in current from 100% of THDi to typical values lower than 5%; the filters are made up of capacitors that form a resonant circuit with a reactor that has a high impedance path at the fundamental frequency and a low impedance path at higher specific frequencies.
Passive filters are more commonly connected to individual loads in the system rather than to the common coupling point since the application requires a consistent load for effective harmonic mitigation.
The passive harmonic filter is installed in series with the line and therefore must be chosen according to the current absorbed by the load or by the group of loads. Esscom passive harmonic filters guarantee excellent attenuation and do not need to be tuned with reference to the impedance parameters of the installation site.
