Influence of power factor compensating capacitors on estimation of harmonic distortion

Introduction of a tariff system which also considers the harmonic injection level is gaining importance as a mechanism to limit the increasing levels of harmonics in power systems. Many researchers have proposed methods to quantify the harmonic power flow from both supply side and load side so that penalties for harmonic injection can be introduced into the tariff structure. The IEEE Standard 1459-2000 defines electric power quantities for nonsinusoidal waveform conditions. Any penalty system introduced for harmonic distortion should be designed to recover the losses due to it and at the same time the penalty should be legally and scientifically acceptable. It should be ensured that no penalty is imposed on a clean consumer who does not inject any harmonics into the system and follows recommended practices of power system management. This paper analyses some of the available methods to quantify the harmonic injections and also identifies cases where a non-polluting consumer is also penalised by these methods. Studies on the possibility of increased harmonic distortion due to attempts made for power factor compensation by traditional methods are presented in the paper. The effectiveness of IEEE Standard 1459 in such cases is investigated.