Design and simulation of 145 kHz wireless power transfer for low power application

Inductive resonance coupling is one of wireless power transfer technique. This paper presents a wireless power transfer design using inductive coupling which comply to the requirement of the wireless power consortium (WPC) standards in the resonant frequency range of 110 ~ 205 kHz. The circuit design and simulation have been conducted using a powerful and free LTspice simulation software with fast fourier transform (FFT) and directive analysis. Transmitter circuit based on royer oscillator circuit and receiver circuit has full wave rectifier, CLC Alter and load of 100 ohm. The result from experiments are the resonant frequency of circuit design of 145 kHz based on the calculation and 142.66 kHz based on the simulation. The difference between the two resonant frequency is caused by the components used in circuit, such as resistance of inductor (RL) transmitter and receiver 0.1 ohm giving resonant frequency 142.66 kHz which close to 145 kHz. Furthermore, the design circuit cannot reach maximum power efficiency when k close to 1, but the designed circuit can result maximum efficiency of 8.14 % when coupling coefficient (k) is 0.90 and the Rl 0.1 ohm.