Medium Voltage Harmonic Filters Through the use of electronic converter drives in conveyors, rolling mills, foundries and other energy- intensive industries, it comes in addition to the reactive power consumption also to strong circuit feedbacks. These harmonics can be minimized only by Harmonic Filters. For this reactive power compensation systems are specially tuned on the harmonic component. The corresponding system technology can be delivered either as a sheet steel housing or with discrete components built-in in a concrete transformer station.