Selective capacitor disconnection for passive harmonic filters
White Paper on effective elimination of capacitive reactive power in a low-load or idling scenario where the system as a whole is connected to the network.
Capacitors must be easily accessible in order for customers or equipment manufacturers to implement a suitable switching device. When capacitors are connected, this can lead to extremely high starting currents. And once they have been connected and disconnected a number of times, switching contacts tend to become worn or welded. This presents the system operator with certain challenges...
"The use of passive harmonic filters is the subject of ongoing debate: Is there an effective way to eliminate capacitive reactive power in a low-load or idling scenario without disconnecting the system as a whole from the network? The obvious answer is simply to disconnect the capacitors used in filters – but this is often easier said than done."
