Wireless Power and Bidirectional Data Transfer Scheme for Battery Charger

Wireless battery charging has been becoming a recent trend in mobile devices. However, there are relatively less research efforts focusing on the large power applications. It is a major drawback of the battery charging in traditional electric vehicles which relies on the use of a plug-in charging device. This paper proposes a wireless power and bidirectional data transmission scheme, data related to battery status, vehicle identification number, or emergency messages that can be mutually transmitted between two isolated units via the same LC tank. The primary unit employs an inverter to yield alternating current and power flow to the load via mutual inductance. The secondary unit transfers data by adjusting current of load, and the primary unit receives data based on the zero-voltage switching method. The primary unit transfers command by trimming the current's curve and the secondary unit receives command and make decoding using the period of carrier wave. It is worth to mention that the design scheme enables it to handle the situation of emergency by sending back the message to the primary unit to make an emergency halt.