Small-signal modeling for phase-shift controlled resonant converters

• Main Authors: Li, Xin, Zhang, Yiming, Chen, Shuxin, Tang, Yi, Zhang, Xin
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Electrical and electronic engineering; Extended Describing Function Method; Phase Shift
• Online Access: https://hdl.handle.net/10356/160237
• Institution: Nanyang Technological University

The extended describing function (EDF) method is widely used in modeling the resonant converters. This article finds that the model of the phase-shift controlled resonant converter deduced by this method might be inaccurate especially when the duty-cycle is close to 1. The reason behind it is investigated, showing that derivation of the inverter bridge model based on its fundamental harmonic will cause error. A novel model of the inverter bridge by Fourier analysis is proposed. Incorporating the novel model into the EDF-based resonant model, the accuracy of the phase-shift controlled resonant converter is greatly improved. A series-series compensated inductive power transfer system is fabricated in the lab to verify the validity of the proposed model.