Exprimental verification of Supercapacitor Assisted Sub Module Inverter (SCASMI) Technique

Abstract

With the rapid growth of renewables and the energy efficiency improvements required in power converters, design engineers are focusing on the incremental increase in energy conversion efficiency. In photovoltaic inverters, losses are mainly contributed by switch losses, copper and magnetic losses and input capacitor losses in general. Reducing these losses step-by-step could help to achieve a high end to end efficiency (ETEE) in solar inverters. The proposed supercapacitor assisted sub-module inverter (SCASMI) technique proposed here is expected to reduce copper losses, magnetic losses and input capacitor losses by applying the supercapacitor assisted loss management concept to the traditional R-C circuit loop. This article presents the preliminary successful results of the SCAMI concept of dividing a single inverter into an even number of sub-inverter modules and coupling them with supercapacitor banks which theoretically reduces the input capacitor losses and the copper losses. Experimental results of the simplest case of dividing a 24 V DC to 240 V AC inverter load into two 12 V DC 120 V inverters with SC banks of nominal 12 V are compared with theoretical values.