A High-Interoperability Optimal Frequency Control Method for the AGV Dynamic Wireless Charging Systems without Communication

In this paper, a communication-free optimal frequency control method for the dynamic wireless charging (DWC) system of automated guided vehicle (AGV) with high interoperability is proposed. By periodically monitoring the primary winding currents, the position of the receiver (Rx) can be located in real-time, and the transmitters (Txs) which are strongly-coupled to the Rx will be activated for power transmission. In order to improve the system efficiency, an optimal frequency control (OFC) scheme for achieving zerophase-angle (ZPA) is proposed. A proportional-integral (PI) loop is employed to achieve quick elimination of the reactive power in primary side. Experimental results show that the positioning and the optimal frequency tuning can be completed within 10ms.The out-phase can be controlled within 3.57° in the worst case, and the system transfer efficiency is increased up to 11.1%. Rxs with different shapes are utilized in experiments as case studies, and the same performance is verified. The results prove the system has high interoperability. Without any bi-directional communication and auxiliary position sensor, the system with the proposed control strategy is proven to be reliable and ecofriendly.