Maximizing energy harvest of the impedance source PV microconverter under partial shading conditions

This paper presents a novel efficiency enhancement method for the multi-mode quasi-Z-source series resonant DC-DC converter (qZSSRC) operating in a boost mode. To decrease the conduction losses associated with the shoot-through control the authors propose to use the reconfigurable rectifier at the output stage of the qZSSRC that enables DC gain control in the most critical operating points by the reconfiguration of the rectifier instead of the shoot-through control. The paper explains the operation and the control principle of the qZSSRC with the reconfigurable rectifier and provides an application example and experimental results of the proposed approach in a 250 W impedance source photovoltaic microconverter operating in partial shading conditions.