Analysis and design of three-coil radio-energy-efficient transmission system with constant current and constant voltage characteristics

Abstract

Abstract To meet the requirements of constant current (CC) or constant voltage (CV) power supply for sensors and other electric loads, this study proposed two types of three-coil WPT (wireless power transfer) system: one with relay coil and another with dual transmitter and single receiver. On the basis of actual coil parameters and target gains, the transmission characteristics of different circuits were analyzed, the design method of compensation network for three-coil WPT systems with CC and CV characteristics was given, and the transmission efficiency and lateral offset competence of the two designs were compared under the same load resistance. Finally, the correctness and effectiveness of the proposed system’s CV and CC output characteristics and its parameter design method were verified through physical experiments. Results show that under CC condition, the transmission efficiency of the three-coil system with relay coil is lower than the dual-transmitter and single-receiver type. Moreover, under CV, the transmission efficiency and offset characteristics of the former are higher than the latter.