Structure and circuit solution of a wireless power transfer system for application in mobile robotic systems

Abstract

This paper presents the development of a medium-power wireless power transmission system for use in robotics and other applications. The presented system can be used to power devices or charge batteries. The system is based on the principle of inductive power transmission. A feature of the system is the use of a resonant self-oscillator, for which the transmitting LC circuit of the system is a frequency setting. The use of identical receiving and transmitting resonant circuits makes it possible to refuse additional frequency control devices in the receiving part of the system. The presented circuitry solution of the wireless power transmission system ensures operation in the resonance mode in the receiving and transmitting circuits, where the receiving and transmitting coils are at various positions relative each other, while not requiring a dedicated monitoring and control system for this. Experimental verification of the proposed solution was carried out on a prototype of a system with shell elements, shielding from magnetic fields, while the maximum level of efficiency of the system without an output stabilizer in the receiving part was 80.41%, with a transmitted power of 131.5 W, at a transmission distance of 15 mm. The dependency curves of the efficiency and the transmitted power were obtained for three distances of energy transfer — 0 mm, 15 mm and 30 mm. With distances between the coils up to 30 mm, the efficiency of the system is above 70% with a transmitted power of more than 55 W. Key words Wireless charging system, wireless power transmission, resonant oscillator, wireless power transmission efficiency. Acknowledgements This research is supported by the RFBR, project no.19-08-01215_А.