Switched mode power supply, inverter and string monitoring assembly comprising said type of switched mode power supply

Abstract

The invention relates to a switched-mode power supply () for supplying the components of a photovoltaic system () with a constant DC output voltage (U), comprising connections () for connecting to the photovoltaic modules () of the photovoltaic system () for providing a DC input voltage (U), a DC/DC voltage converter () comprising at least one switch (), a transformer (), a control device () for controlling the at least one switch () at a switching frequency (f) for obtaining the desired DC output voltage (U), an output equalizing voltage () and connections () for providing the DC output voltage, as well as the inverter () and a string monitoring assembly () of a photovoltaic system (). In order to obtain a DC output voltage (U) with the losses as low as possible for a very wide range of DC input voltages (U) between 200 V and 1500 V, the DC/DC voltage converter () is formed by a combination of flyback and forward converters having two serially arranged switches ('). Said switches (′) are connected to the control device () which is designed such that the control of the DC output voltage (U) occurs such that the switches (′) are switched in accordance with the flow on the primary side passing through the primary winding () of the transformer ().