Comparison and Analysis of the Contactless Power Transfer Systems Using the Parameters of the Contactless Transformer

As contactless transformer has large airgap, long primary wire (over several tens meter) and multi-secondary wire, it has large leakage inductance, small magnetizing inductance and poor coupling coefficient (usually lower than 0.5). Therefore, large magnetizing current flows through entire primary system due to small magnetizing inductance and the overall system efficiency will be low. To improve efficiency of the overall system, several kinds of resonant converter can be chosen. In this paper, we analyze and test several kinds of contactless power transfer system such as series resonant converter, series-parallel resonant converter (in this case, series resonant frequency is equal to parallel resonant frequency), and resonant converter with matching transformer. This paper shows analysis and simulation results of each contactless power transfer system. And the results are compared and verified on the 30 kW experimental prototype