The Effects of Harmonics on Capacitors include additional heating – and in severe cases overloading, increased dielectric or voltage stress, and unwanted losses. Also, the combination of harmonics and capacitors in a system could lead to a more severe power quality condition called harmonic resonance, which has the potential for extensive damage.
Also, the combination of harmonics and capacitors in a system could lead to a more severe power quality condition called harmonic resonance, which has the potential for extensive damage. Consequently, these negative effects will shorten capacitor life.
Capacitors are typically installed in the electrical power system – from commercial and industrial to distribution and transmission systems – as power factor correction devices. However, even though it is a basic component of a harmonic filter (aside from the reactor), it is not free from the damaging effects of harmonics.
In the presence of harmonics, the total power factor is defined as total power factor = TPF = cos0 = Ptotal Stotal (5-6) where Ptotal and Stota1 are defined in Eq. 5-4. Since capacitors only provide reactive power at the funda- mental frequency, they cannot correct the power factor in the presence of harmonics.
Capacitor Bank Behaves as a Harmonic Source. There are many capacitor banks installed in indus- trial and overhead distribution systems. Each capaci- tor bank is a source of harmonic currents of order h, which is determined by the system short-circuit impedance (at the capacitor location) and the capac- itor size.
For small capacity rectifier circuits such as those for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously.