Line filters       

We offer line filters up to high outputs in passive and active versions to reduce harmonics and to protect the system against overvoltages.

The selection of a suitable solution is made taking into account the situation on site. The effectiveness and interaction with the consumers also connected to the network is checked using computer-aided simulation processes.

Passive line filters essentially consist of suitably arranged inductances and capacitances. Suitable resonant circuits are formed from these elements to match the harmonics to be filtered. The passive filters are used to solve limited problems.

Passive line filters rae connected with two disadvantages:

• The filter units are matched to the respective harmonic to be filtered and therefore only work in this narrow frequency range.

• Additional energy storage devices are added to the power supply system already affected by harmonics. Experience shows that this creates the risk of additional resonances that can overload the components involved and destroy them through overheating. Therefore, a careful check is required before using a passive filter.
• A passive line filter is not protected against future changes in the power supply system

Active line filters, on the other hand, have controlled semiconductors in addition to the energy storage device. The electronic control detects deviations in the network or a downstream consumer and regulates them. There is no danger of additional excited resonances. Future changes of the power supply system are also corrected.

Our filters are delivered as a compact unit. On site, they are only connected to the network and checked by our specialists for proper function.