The Borgna-Converter - A new Topology for highly efficient PV Inverters

In this paper, a family of new and simple topologies for highly efficient, non-isolated switched-mode electronic power converters is introduced. Basically, these converters are quite similar to two-channel, interleaved buck-, boost- or buck-boost converters. However, the two sub-converters are connected with a small coupling capacitor in parallel to a small bypass switch. Also, the method of control of the power semiconductors is different. Due to these simple modifications, zero-current / zero-voltage switching is achieved, effectively reducing switching losses and electromagnetic interferences. With a prototype, the authors could show that more than 99% of efficiency can easily be achieved. However, compared to other soft-switching topologies, the complexity of these converters is low, and their method of control is simple. Even though the total number of power electronic components is higher compared to standard switched-mode power converters, the high efficiency and low electromagnetic interferences lead to reduced efforts for cooling and interference suppression, which compensates the costs of the power electronic components. This makes these new topologies ideally suited for cost-sensitive applications with high demands on efficiency such as photovoltaic inverters, power optimizers or battery storage systems. In addition to photovoltaic applications, there are several other areas in which these new converters can be used, such as electric cars or uninterruptable power supplies.