Control of an Inductive Power Transfer System Using a Double Coil Structure

Abstract

This paper presents the design of the control of the system using a double DD coil structure. The double DD coil is a layered coil structure that consists of two single DD coils, rotated to each other by 90°. A large-signal and small-signal model of the proposed IPT system are designed for control synthesis. The small-signal model is derived from the large-signal using harmonic approximation and the extended describing functions (EDF). For the small-signal model, voltage and current control schemes were proposed for the purpose of wireless battery charging. The robustness of the control is tested on a small-scale IPT system using double DD coils and resistive load. The results are evaluated at different reference voltages, currents, loads and coupling coefficients.

A Control of a z-Axis Rotation-Tolerant Wireless Power Transfer System Using a Double DD Coil

“…The IPT system using double DD coils, presented in [12,13], proposes that the receiver side is not rotated to the transmitter side. The IPT system transfers power wirelessly via the DD1 transmitter and the receiver coil, which are not coupled with the DD2 transmitter and the receiver coil.…”

“…Equations (10) to (13) are describing the resonant parts of the system, which include AC components of currents and voltages. The rectifier circuit, presented in Figure 5b, includes DC components.…”

“…Same goes for DD2 transmitter coil. This enables rotation tolerant IPT systems, however, the system cannot be studied as two separate IPT systems, as presented in [13]. Therefore, a new dynamic model should be derived.…”