Passive Paralleling of Multi-Phase Diode Rectifier for Wireless Power Transfer Systems

To improve the power level of a diode rectifier, a multi-phase diode rectifier can be employed to increase the current rating. This brief proposes a passive current balancing method for a multi-phase diode rectifier in a series-series compensated wireless power transfer system. For an N-phase diode rectifier, the receiver-side compensating capacitance is split into N branches, forming a parallel resonant network with the newly added parallel resonant inductors. The circulating currents can be greatly suppressed by the parallel resonant network. The resonant inductors only withstand differential-mode currents, which are small. Thus, these inductors are small and low-cost. Experimental results reveal that the proposed method can well balance the phase currents of the three-phase diode rectifier.