Effectiveness of filter types on efficiency in networks containing multiple capacitors and harmonic sources

This paper investigates the effectiveness of two types of passive filters used for harmonic mitigation in a power system containing multiple capacitors and harmonic sources that cause multiple resonance points. They are notch and second order types installed at the point of common coupling (PCC) and include the utility capacitor bank as a component in their designs. Traditionally, the focus is only on mitigating total harmonic distortions (THDv & THDi). In this study their effectiveness is extended to evaluate the impact of these filters in terms of Total Power, Efficiency and Severity of Resonance factors when an unacceptable distortion is present. The effectiveness is investigated using the SUPERHARM/TOP software package. Computer models are developed to conduct harmonic penetration and harmonic scan resonance studies. Case studies are conducted for a network without a filter, with a notch filter and then with a second order filter. The filters are analysed at the input to the network and effectiveness factors are used to evaluate efficiency.