A Generalized Steady-State Model for Bidirectional IPT Systems

Bidirectional inductive power transfer (BD-IPT) systems are high-order resonant circuits, which are complex in nature and sensitive to variations in system parameters and control variables. Consequently, modeling and design of BD-IPT systems are relatively difficult in comparison to unidirectional IPT systems. An accurate model that predicts the behavior of BD-IPT systems under different operating conditions is invaluable but yet to be reported. This paper, therefore, proposes a generalized steady-state model through which the behavior of BD-IPT systems can be accurately characterized. The proposed mathematical model is comprehensive and includes the effects of harmonics and sensitivity to variations in system parameters and control variables. Using the model, this paper investigates the behavior and sensitivity of BD-IPT systems under a range of practical operating conditions. The validity of the proposed generalized model, which is verified using the results of a 1-kW prototype system, provides a clear insight into BD-IPT systems and is expected to be useful at both design and implementation stages.