Analysis and design of a single-phase Flyback microinverter on CCM operation

Nowadays, decentralized grid-connected photovoltaic systems with one AC Modules (ACMs) are preferred because power loss of the system is reduced due to removing the mismatch between the modules and a separate MPPT can be applied for each module. This is to increase the overall efficiency, when compared to the central inverter systems. The Flyback type inverter is quite simple for inplementation of one ACM and it has been previously investigated in Discontinuous Conduction Mode (DCM) operation as a Current Sourse Inverter. In this paper, a control strategy to inject a sinusoidal current into the grid with unity power factor for Flyback inverter in Continuous Conduction Mode (CCM) operation is presented. Analysis, small signal analysis and design procedure of Flyback micro-inverter for ACM are presented. The validation of the proposed design will be confirmed by experimental results of a 150W hardware prototype.