A novel low cost solar central inverters topology with 99.2% efficiency

For solar central inverters, high efficiency is still a very important issue. It increases the yield, but even more important, it reduces the thermal stress of all components, minimizes the cooling effort or allows higher ambient temperatures. The main challenge is not only to reach high peak efficiency in one operation point but more to provide a good performance over the whole voltage and power range. In this contribution, a new topology for central inverters connected to the medium-voltage grid is presented, analyzed and practically examined. Measurements on a 100 kW prototype prove this concept by an excellent high and flat efficiency graph peaking at 99.2 %. This result is obtained with conventional silicon semiconductors.