Open AccessPower efficiency optimisation of a three‐coil wireless power transfer using compensatory reactance
Author(s) -
Wang Quandi,
Wang Yingcong
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.2018.5378
Subject(s) - wireless power transfer , electromagnetic coil , reactance , relay , maximum power transfer theorem , transmitter , inductive coupling , wireless , coupling (piping) , capacitor , electrical engineering , control theory (sociology) , power (physics) , electronic engineering , computer science , engineering , physics , telecommunications , mechanical engineering , channel (broadcasting) , voltage , control (management) , quantum mechanics , artificial intelligence
Magnetic coupling resonant‐wireless power transfer (MCR‐WPT) has attracted considerable attention in recent decades. A relay‐coil structure is utilised to extend the transfer distance between the transmitter side (Tx) and receiver side (Rx). This structure increases the complexity of analysing and optimising the operation of the system. The optimal compensatory capacitors of a three‐coil wireless power transfer (WPT) system with a relay coil were investigated based on the transfer efficiency. The WPT system is modelled according to the circuit theory using the magnetic coupling between the Tx and the Rx. The condition to derive the optimal efficiency is deduced into a polynomial equation using only the compensatory reactance of the relay coil. These real solutions are theoretically compared to determine the global optimum. An experimental prototype is implemented, and the experimental results agree well with the calculations.