A High Voltage Gain Isolated PV Micro-Converter With a Single-Voltage Maximum Power Point Tracking Control Loop for DC Micro-Grid Systems

A high voltage gain, isolated high frequency Photo-voltaic (PV) microconverter with natural continuous conduction mode (CCM) input current and a wide range of zero voltage switching operation is proposed for use in dc microgrid systems. The proposed converter consists of an integrated CCM boost converter and a capacitor inductor inductor (CLL) step-up resonant converter. Further, a new single voltage loop based maximum power point tracking (MPPT) control technique that utilizes the converter's resonant capacitor voltage is also proposed. Theoretical analysis and operating principles of the proposed converter, as well as the descriptions of the proposed MPPT control scheme are provided. Results on a 220 W, 230 kHz and 380 V-output hardware prototype are presented to demonstrate the performance of the proposed step-up PV converter.