A contactless power transfer system with capacitively coupled matrix pad

Capacitively Coupled Power Transfer (CCPT) technology has been proposed recently as an alternate contactless power transfer solution. This paper proposes a CCPT system with a matrix type of primary charging pad to maintain desired output voltage regardless of the positioning and alignment of the pickup. The capacitive coupling and system performance are analyzed in details, and a new algorithm is developed to control the proposed system. A prototype CCPT system using readily available aluminium sheets as the capacitive coupling pad is developed to prove the concept design. The system demonstrates that 0.7–2.5W output power can be obtained under coupling variation.