Wireless Power and Drive Transfer for Piping Network

This paper proposes and implements a new wireless power and drive transfer (WPDT) system using wireless switches. A wireless piping network is conceived especially for pipeline transportations and in-pipe robots desiring wireless motor drive. Also, a multi-frequency resonant network is newly explored to generate the variable-frequency-modulated magnetic fields where the wireless switches can extract the drive information directly. Differing from single-frequency T-circuits, this multi-frequency network can offer different resonant frequencies which are not only coupling-independent but also large-scale load-independent. Importantly, it can realize both the power self-equalization and zero-phase-angle operation in transmitter and receiver circuits. To conduct the conceived WPDT, the magnetic resonant modulation is used to control the wireless switches automatically at the receiver side, thus flexibly enabling the bidirectional motions of DC motor and the variable-frequency speed control of AC induction motor. The experimental system efficiency can reach 83.5% based on a 200-W prototype at a 130-mm distance. Both theoretical analysis and hardware experimentation are given to verify the feasibility of proposed WPDT system for wireless piping networks.