LLC resonant converter for electric vehicle battery chargers

Abstract

This study presents a new LLC resonant converter with two transformers in parallel for the electric vehicle battery charger. This topology achieves the zero-voltage switching for main switches in the entire charging profile. In addition, the zero-current switching for output rectifier diodes is extended under charging condition. The proposed charger provides a wide range output voltage for the battery system. Moreover, in order to maintain the high efficiency under charging, the charger adopts a bidirectional switch. At low-output power condition, the charger uses one transformer to transfer the energy. Finally, the design procedure is provided and implemented in a prototype charger with the input DC link 400 V and the output voltage of 36-58 V. Experimental results are presented to demonstrate the system performance. The maximum power is up to 700 W and the peak efficiency is as high as 93.6%.

Hybrid coupler for 6.78 MHz desktop wireless power transfer applications with stable open‐loop gain

“…Using fundamental approximation [28], half bridge at the primary side of Fig. 2 can be simplified as a sinusoidal voltage source.…”

Scaling Rules at Constant Frequency for Resonant Inductive Power Transfer Systems for Electric Vehicles

“…L 1 and L 2 represent the self-inductances of transmitter and receiver respectively and their magnetic coupling is modelled with the mutual inductance M. Resistors R 1 and R 2 represent the ohmic losses in the coils. By applying the fundamental harmonic approximation [21,22], the source is modelled with a sinusoidal voltage source of rms value V 1 and angular frequency ω. Since a rectifier and a filter are used at the receiver side [11,23,24], the load is represented through an equivalent resistance R L given by the ratio between the first harmonics of voltage and current at the rectifier terminals.…”

Analysis and design of asymmetric CLLC resonant DC‐DC converter

“…In recent years, topologies of soft switching resonant DC‐DC converter, especially LLC topologies, are drawing increasing attention from the world . LLC resonant converter was of natural soft switching properties, so the inverter switches achieve zero voltage switching (ZVS), and rectification switches achieve zero current switching (ZCS) without any auxiliary circuit . However, a lot of the current researches attach much importance to the unidirectional LLC resonant converter.…”