Power disturbance and harmonic distortion in electrical systems have proven to be fatal to equipment, cables, transformers, capacitor banks etc. The situation has deteriorated further with the use of products such as variable speed drives, soft starters, rectifiers, UPS, discharge lamp etc.
These devices will generate or increase the harmonic distortion and high frequency interference in the power system caused by non-linear loads. These disturbances will cause overheating to cables, transformer and related equipment etc.
Detuned Harmonic filter reactors are connected in series to the capacitors banks and the main purpose is to prevent the harmonic current cause by non-linear loads flowing into the capacitor and cause premature failure. It is also to prevent the resonance of the system.
Detuned Harmonic Filter Reactors are manufactured according to the Filtering % p and the required kVAr is the ratio of inductance to capacitance.
For a 50Hz system:
p=7% = 189Hz is used where protection to capacitor and harmonics reduction is required
p=6% = 204Hz is to be used where the system is rich in 5th harmonics and above
p=13% = 139Hz is used where voltage distortion exceeds permissible limit current
Detuned Harmonic Filter Reactors can be manufactured as single-phase or three-phase, choosing the tuning frequency according to the dominant harmonic current order in the system according to the bus bar voltage and capacitor impedance / power.
Detuned Harmonic Filter Reactors do not destroy harmonic components in the system. It only prevents the harmonic current from increasing in amplitude.