ABSTRACT

The harmonics from the point of generation will penetrate into the power system. The purpose of harmonic analysis is to ascertain the distribution of harmonic currents, voltages, and harmonic distortion indices in a power system. Direct measurements can be carried out using suitable instrumentation. In a noninvasive test the existing waveforms are measured. The distribution of harmonic voltages and currents are no different for networks containing one or more sources of harmonic currents. A voltage scan may be carried out by applying unit voltage to a node and calculating the voltages versus frequency in the rest of the system. For simplicity, all the harmonics may be considered cophasial. This does not always give the most conservative results, unless the system has one predominant harmonic, in which case only harmonic magnitude can be represented. The simplest harmonic model is a rigid harmonic source and linear system impedance.