Photovoltaic inverter with high efficiency over a wide operation area - a practical approach

Traditionally, importance of efficiency is valued highest for PV (Photovoltaic) inverters. The driving factors are the benefits on installation costs, logistics and real-estate. Obviously, lots of recent research has been dedicated to the performance enhancement of PV inverters. However, the best European efficiency of commercially available inverters (above 100 kW) is 98.3 % and this figure is true only for a part of the actual PV voltage range. For most of the practical purposes, the efficiency specified goes down by 1.5-2 %. Most of the topologies in research are not able to make their way to the market due to practical considerations of manufacturers and customers (agency norms, EMI, reliability etc). Lot of research has been dedicated to develop novel topologies and very little has been done towards practical innovative solutions. This paper presents a practical approach, to achieve European efficiency of 98.7 % and, at the same time minimizing the costs. As the solution is simple, it will motivate the industry to implement it for immediate benefits. The work concentrates on commercial PV inverters in the power range of 100-500 kW. This paper also acts as performance baseline for researchers working on novel topologies.