A Secondary-Side Rotating and Segmented Capacitive Power Transfer System With Low Output Voltage Fluctuations Based on Three DC Busbars

In mechanical power transmission equipment, the power shafts are common mechanical structure. It is not feasible to use traditional power supply methods to supply power from fixed power sources to rotating equipment. Capacitive power transfer (CPT) technology has the advantages of flexible and portable couplers, low eddy current loss, and these advantages are well suited to the power supply needs of equipment installed on rotating bodies. However, there are also some shafts with large diameters that can cause serious electromagnetic radiation and standby losses when using long receiving plates, and a series of problems such as voltage drops caused by segmented couplers. Therefore, this paper proposes a rotating segmented CPT system with low output voltage fluctuation based on three DC busbars; it establishes a mathematical model and equivalent circuit for the system's multi-port capacitive coupling; and achieves the super-position of adjacent rectified output voltages. Experimental results confirms that the system maintains a basically constant output voltage throughout the entire rotation process. In this process, the output voltage of the system drops from 47V to 41V, with a maximum variation rate of 12.77%. The system output power reaches 82W, and the peak efficiency achieves 84.97%.