Wireless Power Transfer 2.5 kW with Simple Control and High Efficiency

This paper presents design and construction of a 2.5 kW wireless power transfer apparatus, supplied from a single phase mains with good power factor, high efficiency and simple control circuits. The coils are 30 cm in diameter and the power is transferred over a distance of 25 cm. The efficiency is 91 %, power factor is 0.97 and operating frequency is 320 kHz. The receiving-side output voltage is approximately 230 V DC and can be modified with a different receiving LC circuit. The coupled resonant circuits are designed optimally for the best efficiency. The control circuit principle description is included. The practical construction is shown and measurement results are presented.