Elimination method for the Transmission Efficiency Valley of Death in laterally misaligned wireless power transfer systems

This paper first identifies the Transmission Efficiency Valley of Death (TEVD) in laterally misaligned magnetic resonance coupled (MRC) wireless power transfer (WPT) system. The paper then presents a method to eliminate the TEVD by angularly rotating the transmitter coil (Tx) or receiver coil (Rx). Simulation results of the ANSYS® HFSS® 3-D physical model with 5-turn spiral shape four-coil MRC-WPT system with 60cm outer diameter show that when the Rx is 30cm vertically away from the Tx, TEVD exists when the lateral misalignment value (MIS) ranges from 50cm to 70cm. The presented method eliminates the TEVD and extends the high efficiency range from MIS = 50 cm (83.3% of the Rx diameter) to MIS = 70 cm (117% of the Rx diameter).