Design and Mathematical Analysis of a Single-Phase PV Residential Micro-In

Abstract

Photovoltaic (PV) system architectures are being designed to optimize
energy extraction. Micro-Inverter (µI) architectures are gaining in
popularity as they are increasing the efficiency and the power extracted
from the PV module and mitigating the shading effect. This work details
the design of a proposed DC-AC µI. The design incorporated a
combination of a virtual DC bus inverter and a proposed three-winding
coupled transformer which is based on a Y-source impedance
configuration. High voltage spikes and low voltage regulation arises from
loosely coupled inductors in the ferrite core. On the other side, transformer
elimination in the µI configurations can generate high common-mode
voltage as a consequence, leakage current can cause distortion of the grid
current. In this paper, the developed transformer with less µI can overcome
all the drawbacks mentioned above. The proposed µI has been created and
designed to remove both leakage inductance and leakage current caused
by a transformer-less µI configuration. In addition, the converter greatly
reduced component stress and increased the converter voltage gain
capability in a single stage. Using Mathematica 11.2 software, a thorough
mathematical model of the µI was built and proved. To assess the
performance and demonstrate the features, PLECS 4.2 simulation software
has been used, which shows a preference for the proposed µI over the
traditional impedance source inverters in terms of boosting capability and
components voltage stress.