Modeling and optimization of pavement scale-model for magnetically coupled resonant in wireless power transmission systems

Electric vehicles (EVs) can achieve energy conservation and sustainable development. However, the development has been limited by mileage and battery size. The application of magnetically coupling resonant (MCR) wireless power transmission (WPT) can be used to solve the drawbacks of the EVs. In this study, the parameters of the primary coils and the secondary coils were selected and optimized by using COMSOL Multiphysics finite element software. The influence of the primary coils on the mutual inductance of the secondary coils were conducted to adopt the modes of non-superposition, 1/3 superposition and 1/2 superposition, respectively. The mutual inductance formulas of coils were derived in different superposition modes, the calculation results were in well coincided with the simulation. The pavement scale-model based on MCR wireless power transmission was established by simulation and calculation results to determine the coil parameters and the optimum superposition mode. The influence of the secondary coil on the wireless charging efficiency was explored in static and different moving speeds. The results showed that speed of 40–60 cm/s and spacing of 28 mm were deemed as the optimal charging efficiency when considering the requirements of movement state of the EV and coil embedment.