Asymmetrical Half-Bridge Flyback for the Design of Auxiliary Power Supplies in Hybrid Inverters

EasyChair Preprint 13855

Abstract

Hybrid inverters are gaining importance because they combine the benefits of regular solar inverters with the flexibility of battery inverters. For increasing their deployment, the aim is to make them efficient and economically viable. This requires techniques that raise the output voltage of the photovoltaic strings. Hence, the auxiliary power supply, which is the focus of research in the last few years, must be capable of efficiently providing a high gain conversion ratio over a wide input voltage range. It must keep the sensing systems, gate drivers and control system in permanent operation. Solutions based on the flyback topology are available in the state of the art. However, they have some limitations: the operating range of the input voltage is wide and the voltage stress that semiconductor devices must withstand is high. In this paper, the Asymmetrical Half-Bridge (AHB) flyback preceded by a boost with PFC capability is proposed for the design of the auxiliary power supply. With this topology, the maximum voltage stress to be withstood by the devices is limited to the input voltage. In addition, it has a good performance over a wide input voltage range, and thanks to its hybrid nature between flyback and forward topologies, it allows reducing the size of the transformer, thus increasing its power density. A converter design that can operate under the challenging specifications of this architecture with an input voltage between 100 V and 1100 V, and providing an output of 24 V and 75 W, is proposed to validate its operation.

Keyphrases: Asymmetrical Half-Bridge flyback, Auxiliary power supply, Hybrid Inverter, solar energy

@booklet{EasyChair:13855,
  author    = {Cristina Martos-Contreras and Alfredo Medina-Garcia and Juan Cruz-Cozar and Jorge Perez-Martinez and Victor Toral and Noel Rodriguez and Diego P. Morales-Santos},
  title     = {Asymmetrical Half-Bridge Flyback for the Design of Auxiliary Power Supplies in Hybrid Inverters},
  howpublished = {EasyChair Preprint 13855},
  year      = {EasyChair, 2024}}