| Abstract |
A 3-phase transformerless power electronic conversion system is used as an interface between a photovoltaic array and the utility line. Because of the absense of a power transformer, and because of a high array voltage, the efficiency is high. An MPPT is used for optimal utilisation of the PV-array, which results in a high yield of the system. The power electronic converter is based on the topology of a Pulse Width Modulated Current Source Inverter (PWM-CSI). The inverter is operated at a high switching frequency (20 kHz), so that waveforms with a low distortion are generated, while the power factor is near unity. Both on the ac side as well as on the dc side the harmonics and the ripple components are considered. Performance measurements of a 1 kVA-prototype system shown that the efficiency of the system increases from 65 % at 20 % load to 85 % at full load. From 20 % to full load, the power factor exceeds 0.95. |
