A Magnetic-Field Coupled Dynamic Wireless Power Supply System With Constant Voltage Output for DC Servo Motors

The moving sorting machines are widely deployed in the express logistics industry. Wireless power supply instead of the traditional sliding contact line power supply to power the DC servo motors of the moving sorting machine can greatly improve the reliability of the moving sorting machine and reduce its maintenance cost. However, affected by the working characteristics of the sorter, the DC servo motors of the sorting machine trolleys are often in the working state of “on-load start” - “short time throwing” - “no-load pause”, which will cause the wireless power supply bus voltage to decrease or rise rapidly, and seriously affecting the normal operation of the DC servo motors. Therefore, it is of great significance to design a dynamic wireless power supply system of moving DC servo motors with excellent performance against impact load. First, the magnetic coupling mechanism adopts the long-track transmitting and E receiving structure to keep a smooth mutual inductance within the moving range; Then, the system adopts the LCL-S compensation topology to guarantees the characteristics of the constant voltage on the secondary side, and the digital closed-loop Buck converter is connected in the rear stage to achieve accurate and constant voltage output. To overcome the bus voltage to rapidly decrease or rise caused by the impact load, an energy compensation method is proposed. Finally, the prototype of magnetic-field coupled dynamic wireless power supply system was built, which successfully supplied the DC servo motor of the short-time working sorting machine trolley with exceeding 20% of rated load, and the bus voltage up and down error was less than 10% and the energy transfer efficiency can reach 86.85%, which met the design requirements.