Efficiency Optimization of LCC-S Compensated Multiple-Receiver Bidirectional WPT System for Stackers in Automated Storage and Retrieval Systems

In automated storage and retrieval systems (ASRS), adopting wireless power transfer (WPT) technology is an available way to avoid the drawbacks of the contact power supply system for multiple stackers. When stackers are dropping goods, it is meaningful to recycle the power generated by the motors and feedback to the other stackers or the ground power supply for improving the overall efficiency of ASRS. This article proposes a bidirectional WPT (BD-WPT) system for multiple receivers. Based on the values of transmission power and the power flow directions of receivers, a general model of the BD-WPT system is established with identifying the system operation modes and their boundaries. To achieve flexible switching among different operation modes and adapt the required transmission power with maximum efficiency point tracking (MEPT), a control strategy of the BD-WPT system is proposed. In the 2-kW experimental prototype built, the power demands can be met in real time, and the power fed back by the stackers can be supplied to other loads or recycled by the ground power supply with good dynamic performance. Compared with the system without MEPT, the efficiency of the proposed system is improved by 26.7% at most, and the maximum efficiency achieves 96.4%.