State-variable analysis of wireless power transfer networks for linear and nonlinear loads

A state-equation approach to modeling wireless power transfer (WPT) networks is presented. The state-variable approach was investigated because it permits termination of the network in nonlinear loads, which is not possible with the usual analysis with the phasor transform. The modeling work presented here involves a three-coil WPT network terminated in a rectifier and filter; simulation has been carried out using constant-resistance and constant-power loads. The validity of the model was established by comparison with commercial circuit-analysis software.