Estimation of Power Losses Caused by Supraharmonics
Keywords:Power losses, power quality, supraharmonics
Nowadays increases the number of power electronic devices in distribution electrical networks rapidly. Modern generation and consumption units use high switching frequency power converters for the network connection and therefore cause the voltage and current distortion in the frequency range over 2 kHz (so-called “supraharmonics”) in addition to conventional harmonics. Supraharmonics cause additional power losses in electrical equipment. The goal of the offered paper is the estimation of power losses caused by supraharmonics. The method of the supraharmonic power losses estimation combining the analytic determination of AC cable resistances at the supraharmonic frequencies with the use of measurement results of supraharmonic currents in a real MV/LV cable network is considered in the paper. In the paper is shown that supraharmonic power losses in a MV cable under study can reach the values of several percent with respect to the power losses at the fundamental frequency and can exceed 10% regarding the power losses caused by conventional current harmonics.