Harmonic Cancellations in Parallel Active Front End Inverters in Distribution Networks: IEC 61000-3-16 and Phase-Angles

Abstract

Harmonic emissions have been changed in distribution networks, with respect to frequency range and magnitude, due to penetration of modern power electronics systems such as Active Front End (AFE) technology utilised in renewable energy systems such as solar and wind farms. This paper presents current harmonics generated by parallel AFE inverters in distribution networks for the frequency range of 0-2 kHz to address harmonic limits in IEC 61000-3-16 standard. In this paper a comprehensive review and analysis of phase angles of all harmonics generated by grid connected power electronics systems have been carried out. The impact of phase angle for harmonic cancellation at a system level depends on the phase angle variation over a large time period. The outcome of this investigation identifies harmonic emission and behaviour of parallel grid connected inverters with AFE technology at a system level in low voltage distribution networks.