The Influence of the Network Impedance on the Nonsinusoidal (Harmonic) Network Current and Flicker Measurements

The influence that small variations of the network impedance may have on the nonsinusoidal (harmonic) network current at the point of connection of a harmonic distortion measurement system, as well as on flicker measurements, has been studied. In this respect, an equivalent circuit was devised as a possible low-voltage urban network model. Harmonic disturbances, using three different disturbance sources, and voltage variations that induce the flicker sensation, using square modulation waveforms, were simulated on a computer. The variation with ±10% of the magnitude of the network impedance at 50 Hz was also simulated, and the influence it may have on the spectral distribution of current and power, as well as on the modulation depth generating the flicker sensation, was analyzed.