Negative impacts on power quality, caused by frequency-controlled drives, welding lines or computers‘ power supply units for example, can have serious consequences: if a sensitive device, such as an electronic control unit, is damaged by harmonics, total production failure may result. Even the supply grid itself can experience impermissible interference or dangerous overloading due to reactive power, load imbalance, fluctuation in voltage (flicker), and high harmonic currents.
Active filters reliably and accurately compensate for this interference. They measure current and voltage of a grid section and supply precisely the amount of current required for the desired effect. When harmonics arise, currents are actively generated, opposing the interference in the grid, so that the harmonics are wiped out. To reduce voltage fluctuations (flicker), active filters make use of the fact that inductive reactive power reduces the line voltage and capacitive reactive power increases it. Active filters therefore reliably take the strain off grids, extend the service life of devices and increase the safety of industrial systems.
Compared with conventional, passive filters, active filters can be set very accurately to the prevailing requirements at any time – without the risk of overload. Because the systems can be smaller in size and dynamically regulate their filter flow, they result in fewer losses. Active filters are a future-proofed investment for both industrial networks and buildings.