Detuned reactors are connected with capacitors to tuned filter circuits with resonance in the audio frequency range to reduce, block or filter harmonics or communication frequencies. The detuned reactors are connected either in a parallel configuration in the system (with system voltage applied across them) or in a series configuration (with load current flowing through them).
By using these types of detuned reactors it is possible to avoid following negative effects on system.
Over current during switching on the capacitor banks
Overload of capacitor banks because of the harmonic resonance.
Short lifetime on capacitors
Overheating of the utility transmission cables.
Overheating of the distribution transformer.
Unintended triggering of the protective devices
Distortion of utility voltage waveform and problems on voltage sensitive devices
Interferences on data transmission systems
Unexplainable faults in electronic boards
Choosing the correct detuned filter reactor and capacitor value on detuned power factor correction Systems is very important. To obtain optimum performance form a detuned power factor correction System following criteria must be controlled and met during the pairing of the reactors and capacitors.
The resonance frequency must be chosen according to harmonic analysis of the system
The voltage across the terminals of the capacitor will increase because of the inductive reaction of the reactor. The rated voltage of the capacitors must be chosen according to the resonance frequency.
In detuned power factor correction systems, presence of higher voltage rated capacitors and reactors causes a difference between rated capacitor power and obtained reactive power. The obtained power must be calculated in order to avoid low compensation
The reactors will generate extensive heat due to heavy harmonic load on them.
The cabinets must be designed to disperse this heat.