THE ELECTROMAGNETIC TRANSIENTS PROGRAM (EMTP) AS AN EFFECTIVE TOOL TOEVALUATE ACTIVE POWER FILTERS FOR HARMONIC COMPENSATION

The Institute of Electrical and Electronic Engineers (IEEE) 'Recommend ed Practices and Requirements for Harmonic Control in Electric Power S ystems' sets limits for the current and voltage harmonic distortions a t the point of common coupling in order to maintain an acceptable qual ity of electric power in the presence of nonlinear loads. Both the uti lity and its customers share a common responsibility since enforcement of the above practice by the utility would require that the affected customer use a suitable harmonic mitigating method. To this effect, th is paper demonstrates how the Electromagnetic Transients Program (EMTP ) may be used to investigate two harmonic mitigating methods, namely, the use of shunt passive power filters and the combination of a series active (APF) and shunt passive (PPF) power filters. Both methods redu ce the harmonic currents injected into the distribution system; howeve r, the combination of the series APF and shunt PPFs has a better compe nsation characteristic with a higher capital cost than only shunt PPFs . Before a final decision is reached, the cost of the higher harmonic losses throughout the distribution system when using only shunt PPFs m ust be taken into account.