A high gain Z-source boost DC–DC converter with common ground for solar PV applications

Abstract

This paper proposes a high-gain dc–dc converter with common ground utilizing a Z-source network for low voltage solar photovoltaic (PV) applications. This converter features a common ground and a high output–input voltage conversion factor at a low duty cycle. These converters find their most common application in grid-tied or stand-alone solar photovoltaic systems, particularly those with low output voltages that must be increased to the required level. The presented converter operating duty ratio is within 0–0.5 and maintains similar voltage stress on Z-network components since it employs the conventional Z-source configuration. The presented converter provides a common ground between source and load, unlike conventional Z-network converter. A type-2 closed-loop voltage controller and state–space average model evaluate the converter’s dynamic behavior for reliable and steady performance. A laboratory hardware prototype of 250 Watts is built and low gate signals are generated by using a ARM cortex M4 Microcontroller (STM32F407VGT6). The experimental results confirm that the proposed converter, with a gain of 10.46 and a power of 250 Watts, has a maximum efficiency of around 93%. The experimental results validates the effectiveness of the proposed converter under both constant and shifts in amounts of solar irradiation.