A high step-up Z-source-flyback converter with integrated inductors for photovoltaic applications

Increasing the voltage gain by means of Z-source network will provide some features such as low-voltage stress of semiconductor devices, low duty cycle of the switch and low reverse recovery problem of output diode that leads to improve the converter performance and efficiency. The proposed converter in this paper employs a Z-source network with coupled inductors integrated with flyback converter to make it appropriate for high step-up applications. One magnetic element is used in this converter, which is its main advantage over previously introduced Z-source converters. Steady-state analysis and operation principles of the proposed converter in continuous conduction mode that leads to low current ripple, and low conductive losses for semiconductor devices due to decreasing the RMS currents are presented. In order to verify the theoretical analysis, experimental results of a prototype are provided. This converter's high-voltage conversion ratio will result in 300 V output from 20 V input voltage source for 100 W output power.