Interharmoniques – La perturbation de la qualité de l’énergie qui n’apparaît pas sur les analyseurs d’harmoniques standard
Interharmonics — frequency components that are not integer multiples of the fundamental (e.g. 75 Hz, 130 Hz sur un 50 Système Hz) — are produced by PV inverters, éoliennes, Chargeurs EV, cycloconverters, and HVDC links. Their most dangerous effect: un interharmonique à 58 Hz creates an 8 Hz beat frequency — squarely in the range of peak human visual sensitivity. Cas de terrain: simultaneous PV + Chargeur de VE + microwave on one LV circuit produces stochastic interharmonics causing light flicker. Standard IEC 61000-4-7 analysers cannot correctly characterise them.