De-Tuned Filters

Detuned Filter Reactors are used in series with capacitor banks in power factor correction units. By using these types of detuned reactors it is possible to avoid the following negative effects on the system:

  • Overcurrent during switching on the capacitor banks
  • Incidental resonance of Capacitors along with stray inductance
  • Overload of capacitor banks due to the harmonic resonance
  • Short lifetime of capacitors
  • Overheating of the utility transmission cables.Overheating of the Distribution Transformer
  • Unintended triggering of the protective devices
  • Distortion of utility voltage waveforms and problems on voltage sensitive devices
  • Interferences on data transmission systems
  • Unexplainable faults in electronic boards
De-Tuned Filters Technical Specifications
  • Design : Chokes are produced according to IEC 60938 specification
  • Winding material : Copper or Aluminium
  • Insulation Class : Class F (155 C)
  • Protection Degree : IP00
  • Rated Voltage of Capacitor : As per customer Specs
  • Rated Supply Voltage : As per customer specs
  • Resonance Frequency : 7%(fr:189 Hz)/14%(fr:134Hz)
  • Reactive Power Output : 2.5 KVAR to 100KVAR
  • Thermal cutoff : 135 C
Specifications Of Inductors for 440 Volt Capacitors at 7% (189 Hz)
Capacitor Power (kVAR) Inductance L (mH) Rated Current (Amp) Weight of Choke in Copper (KG)
2.5 17.5 3.2 3.8
5 8.63 6.4 5.2
10 4.31 12.8 6.8
15 2.88 19.2 10.3
20 2.16 25.7 13
25 1.73 32.1 14.3
30 1.44 38.5 17
40 1.08 51.3 23
50 0.86 64.1 25
60 0.72 77 34
75 0.58 96.2 38
100 0.43 128.3 48

Chosing the correct detuned filter reactor and capacitor value on the detuned power factor correction systems is very important. To obtain optimum performance from a detuned power factor correction system, the 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 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.

We manufacture chokes for operation in reactive power compensation systems to protect capacitive batteries. Together with capacitors, they form a resonance system which limits the amplitude of harmonics currents. Generally, as a standard practice, sensors are inserted in reactor windings in order to protect the choke from overheating.