Contactless Energy Transfer System With FPGA-Controlled Resonant Converter

Power supply based on an inductive coupled contactless energy transfer system is presented in this paper. The energy is transferred using a rotatable transformer and a power electronic converter. To minimize total losses of the system, a series resonant compensation circuit is applied assuring zero-current switching condition for insulated-gate bipolar transistors. The analytical expression of the transfer dc voltage gain is presented and discussed. The novelty of the system lies in the application of a fully digital field-programmable-gate-array-based controller and a protection system. The resonant frequency is adjusted by a primary peak current regulator. Some simulation and experimental results illustrating the operation of the developed 3-kW 60-kHz laboratory prototype are given. Although the presented power supply with a rotatable transformer is constructed mainly for robotics and manipulators, the described design and control methodology has general validity and can be applied for a wide class of contactless power supply with core or coreless transformers.