Interharmonic Emission in AC–DC Converters Exposed to Nonsynchronized High-Frequency Voltage Above 2 kHz
Selçuk Sakar, Sarah Rönnberg, Math Bollen
Abstract
More and more devices connected to low voltage networks inject currents in the frequency range above 2 kHz up to 150 kHz, so called supraharmonics. Supraharmonics can appear as synchronized or nonsynchronized to the power system frequency. A device exposed to a fixed supraharmonic frequency are here shown to generate interharmonics when the power system frequency deviates from the ideal 50/60 Hz. Resulting interharmonic frequency and magnitude are determined by three factors, the frequency at which a supraharmonic component exist, the voltage magnitude of that component, and the deviation from 50/60 Hz of the power system frequency. Formation of interharmonics is confirmed in a functional model and validated through the measurements and numerical simulations.