A LCC-Series Based Multiphase Inductive Power Transfer System Employing Duty Ratio Control

This paper proposes an LCC- Series-based multiphase inductive power transfer (MIPT) system that employs duty ratio control (DRC) to control output voltage. In this control, the duty ratio of the switches is varied, keeping the switching frequency constant to control output voltage at the desired level. The duty ratio to output voltage relationship is obtained using Fourier series representation. A compensation network with an LCC-series (LCC-S) configuration is used, which provides load-independent gain characteristics. The analysis and evaluation of three-phase compensating network components are obtained using fundamental harmonic approximation (FHA) as the switching frequency is kept constant at resonating frequency. The results for a 5kW MIPT system are included to validate both open-loop and closed-loop operation under various duty ratios. Further, it includes the variation of rms current of the primary and secondary loosely coupled coil under different duty ratios.