Open AccessStep‐charging technique for CC/CV mode battery charging with low‐cost control components in IPT systems
Author(s) -
Na Kyungmin,
Ma Hyunggun,
Namgoong Gyeongho,
Kim Katherine A.,
Jung JeeHoon,
Bien Franklin
Publication year - 2018
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2018.5450
Subject(s) - battery (electricity) , wireless power transfer , maximum power transfer theorem , electrical engineering , voltage , constant current , power (physics) , controller (irrigation) , electronic engineering , engineering , physics , electromagnetic coil , quantum mechanics , agronomy , biology
In wireless power transfer technology, power control technique is required to realise constant current (CC) and constant voltage (CV) modes for battery charging. CC and CV modes are needed to effectively charge lithium (Li)‐ion batteries to ensure long life span and maximum capacity utilisation. The use of additional battery charging circuitry reduces efficiency, increases volume, and increases circuit complexity. The frequency modulation method is a method that can control power without an additional charging circuit, but a high‐resolution controller is needed to control the voltage and current for charging the battery by frequency modulation. This study proposes a system that controls current and voltage for CC and CV modes through a step‐charging method using a battery hysteresis with a low‐cost control system. The in‐band communication circuit is analysed and used to link the primary and secondary sides of the inductive power transfer (IPT) coils, which enables effective feedback control without an additional wireless communication module. This method enables high‐efficiency charging while minimising the overall size and cost of mobile IPT applications such as power tools. The proposed system shows 90.3% transfer efficiency with a 20.75 V, 4 Ah Li‐ion battery at 7 mm distance.