Design of Symmetric Voltage Cancellation Control for LCL converters in Inductive Power Transfer Systems

This paper presents a new design strategy for Symmetric Voltage Cancellation (SVC) Control used in LCL converters for Inductive Power Transfer (IPT) Systems. It was found that the operating mode that eliminated diode reverse recovery losses in the H-bridge had particularly low losses. An analytical technique is used to calculate the operating modes. Three common control schemes used in LCL converters were computed and normalized graphs are produced to aid designers in making engineering tradeoffs between more efficient switching schemes, total harmonic distortion (THD) and the overall cost of the converter. For a typical LCL converter example, total losses in the H-bridge can be reduced by a factor of 11 by restricting operation to a mode with no diode reverse recovery loss.