A Topology-Morphing Series Resonant Converter for Photovoltaic Module Applications

Residential solar photovoltaic (PV) installations frequently use power optimizers to increase their energy production. In this application, the ability to regulate a wide range of voltage with high efficiency is highly desirable. Thus, this paper proposes a novel hybrid-controlled series resonant converter (SRC) for photovoltaic power optimizers. The converter utilizes the advantage of GaN devices, which have improved switching transition times compared to Si devices, hence providing a lower switching loss. Regulation is achieved with fixed-frequency PWM control on the secondary side, while ZVS and ZCS of the devices are achieved with the proposed resonant tank design. The proposed converter maintains high efficiency over a wide voltage range, making the PV system shade-tolerant while keeping the number of switching devices low. The paper presents the operating principles, the design methodology, and simulation results. The results show a high efficiency over a wide voltage range, as well as a wide load range.