Optimization Tool for Dc-Link Capacitor Bank Design in PV Inverters

The development of a tool is presented for optimizing dc-link capacitors design in PV inverters. Reliability of power converters is well known to be one of the bottlenecks for decreasing the cost of renewable energy systems. Thus, this paper proposes an analysis and design method for estimating the lifetime performance of multiple capacitor bank designs. A case study is performed in a single-stage single-phase PV inverter. A realistic mission profile is used and built with real weather data and combined with a PV model in order to obtain the relevant values of power processing throughout a 1-year operation. A capacitor electro-thermal modeling is done in order to evaluate their operating conditions in time. Results show that the proposed tool is able to provide crucial information to the designer, such as the compromise between lifetime, cost, and volume.