Open AccessThree‐coil structure‐based WPT system design for electric bike CC and CV charging without communication
Author(s) -
Liu Sheng,
Li Xiaoming,
Yang Lin
Publication year - 2019
Publication title -
iet electric power applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.815
H-Index - 97
eISSN - 1751-8679
pISSN - 1751-8660
DOI - 10.1049/iet-epa.2018.5871
Subject(s) - transmitter , electromagnetic coil , wireless power transfer , voltage , compensation (psychology) , electrical engineering , engineering , maximum power transfer theorem , electric vehicle , constant current , battery (electricity) , electronic engineering , power (physics) , control theory (sociology) , computer science , control (management) , physics , psychology , channel (broadcasting) , quantum mechanics , psychoanalysis , artificial intelligence
In comparison with the traditional plug‐in charging systems for the electric bike (EB), wireless power transfer (WPT) systems have superior advantages of convenience and safety. Combining the application requirement range of the EB, this study proposes a three‐coil structure‐based WPT system in order to achieve ideal and reliable constant current (CC) output and constant voltage (CV) output without the need for a sophisticated control strategy and the real‐time communication links between the transmitter and receiver sides. Two ac switches are utilised at the transmitter side to implement the change of charging mode from CC to CV. By correctly selecting the parameters of compensation components, the required load‐independent CC and CV characteristics with zero phase angle in the CC and CV modes can be achieved. Besides this, a load identification method based on the active power calculation used to estimate the equivalent resistance of the battery in the whole charging process, is utilised to judge the switching point from CC to CV mode. Finally, the feasibility of the method is verified through the construction of a laboratory platform with a 3.3 A charging current and a 57 V charging voltage.