Dynamic Gyrator Models for the Transient Analysis of IPT Systems

In this article, a new dynamic gyrator model is proposed for transient analysis of inductive power transfer (IPT). The well-known dynamic phasor is applied to an IPT system and then the dynamic gyrator is derived from the phasor domain circuit. The proposed dynamic gyrator has an imaginary gain similar to a static gyrator; however, it is valid not only for the steady state but also for the transient state. It is verified that IPT with two LC resonant tanks of the fourth order system is degenerated to the second order system. So far, dynamic control of transient IPT circuit was tremendously difficult due to very high order compensation circuits of IPT systems. Any IPT system, regardless of the type of compensation circuits, can be analyzed by the proposed dynamic gyrator without cumbersome equations. The degenerated low-order system with a dynamic gyrator model makes the complicated design of IPT be a substantially simple task. Simulation and experiments for a series-series compensated IPT of 520 W tuned at 50.3 kHz successfully verified the proposed dynamic gyrator model.