Coupling Estimation and Maximum Efficiency Tracking in Multi-Transmitters WPT for Fast Moving Receiver

Abstract

Maximum efficiency tracking (MET) with multiple concurrently-activated transmitters (TXs) has not yet been investigated thoroughly. This paper proposes a fast real-time estimation of coupling coefficients and load resistance for multiple concurrently-activated TXs and a moving RX. This is the first paper that demonstrates iteration-less, fast, communication-less MET with power regulation when the RX is moving across multiple activated TX array. The controller senses only the voltage magnitude of TX coil-capacitor resonator, and the input DC voltage and DC current of inverter. Once the parameters are estimated, the controller sets the converters to maximum efficiency point immediately. The benefits of proposed method are that it does not require a communication channel, extra circuit components for MET, time-consuming iterations and computations, and periodic interruption of power flow due to load disconnection or initialization, all of which were limitations in typical methods. Experimental results show that the proposed method provides a fast response (3.8ms) for an RX moving at 6.84 km/h across multiple TXs.

Keywords

• Dynamic wireless power transfer
• resonant converter
• maximum efficiency point tracking
• multiple transmitters