Single-phase off-grid solar microinverter with common ground and voltage boost operation

Abstract The voltage produced by solar panels can fluctuate because of factors such as irradiance, temperature, and shading. This makes it challenging to obtain a stable voltage suitable for powering devices that use regular household electricity. This article presents a novel solar microinverter that operates in off-grid mode and provide a stable output voltage of 230 V from a low and variable input voltage ranging from 24 V to 46 V. A modified Z-source converter with an active switch achieves the requisite gain. The duty ratio of this switch adapts dynamically in response to fluctuations in the input voltage or load. The operation of the microinverter is controlled by Proportional-Integral (PI) controller, ensuring optimal control and performance. The proposed microinverter provides a common grounding feature between the solar panel and load; this suppresses the Photovoltaic (PV) leakage current. A detailed explanation of the circuit operations, component design and a comparison of the proposed microinverter with existing microinverters are provided. The performance analysis of the proposed topology is validated in real time with a 500VA microinverter.