A Power-Factor-Corrected Wireless Charging System with Simple Control for Indoor Mobile Robots

A conventional resonant-inductive wireless charging system includes a power factor corrector (PFC) to maintain a high input power factor (PF) and low distortion of the input current (THDI). Although a conventional low-power wireless charging system with a PFC has relatively simple power electronic circuitry, its control stage is comparatively complex and expensive. This complexity arises because it relies on multiple feedback loops, as well as a radio communication link with complex communication protocols. As a result, the design complexity and development time are relatively high, and a highly qualified engineer with strong programming and communication expertise is needed. Some state-of-the-art solutions have eliminated the wireless communication link at the cost of increased size of the receiving side. To overcome these drawbacks, this paper proposes a simpler control and communication method that combines output voltage and current limiting with a low-latency wireless communication link transmitting 1-bit logic signals. This approach improves the cost-effectiveness of the control circuit, reduces system complexity, and keeps the receiving side compact, while maintaining performance comparable to conventional and state-of-the-art solutions. The proposed method is validated through simulations and experiments using a 60 W prototype. Results show that the power-factor-corrected wireless charging system with the proposed control and communication scheme achieves a THDI of 4.3%, a power factor of 0.99, high charging voltage accuracy (±0.5%), and satisfactory current accuracy (±9%).