TransformerLess Partial Voltage Architectures for High Power PV Plants

The concept of a partial power converter is promising since it can lead to significant reductions in cost, weight, volume and losses. However, in most cases partial power converters include a transformer to transfer power from one part of the circuit to another. Photovoltaic generators, such as glass-glass PV modules, can withstand high insulation voltages, often exceeding those required by certification standards. This article therefore focuses on a partial power conversion system that does not include any transformer between the PV generators and the low-voltage AC collector. It describes and compares partial power conversion topologies that are currently being patented [12], which facilitate undersizing and the multiplication of MPPT DC/DC converters. This makes the system robust under heterogeneous operating conditions (e.g. temperature and irradiation) between photovoltaic subfields.