Performance analysis of rectangular and double-D transmitters with various receivers for electric vehicle static charging

The inductive charging stations of the future should be able to charge any car, regardless of the type of coil configuration attached to it. In this study the performance of different configurations of coils is investigated. Where the principle of interoperability is studied between the most common types of coils in the IPT system (rectangular and double-D) recommended by Society of Automotive Engineering (SAE) J2954. This interoper-ability analysis is done at a power level of 11.1 kVA and Z3-class ground clearance using the two types of coils on the side of the car, while double D (DD) is used as a general transmitter in one case, and in the other case, a rectangle (R) is used as a general transmitter. Four 3D finite-element models (FEMs), along with compensation circuits, are built to perform the interoperability tests. The circuit models are utilized to determine the frequency of operation and the parameters of compensation circuit that realize the rated power at highest efficiency. The concept of interoperability has been verified through multiple performance indicators, namely coupling coeffi-cient, transmitted power, and transmission efficiency. These indicators were calculated at ideal alignment and the different cases of misalignment, whether lateral or angular. The findings prove that the two different types of receivers (R and DD) can work efficiently and smoothly with the general transmitter, whether DD pad or rect-angular pad are used. At the same time, the nominal power can be transmitted at high efficiency, above the limits permitted by SAE j2954 (>85 % at alignment conditions and >80 % at misalignment conditions).

Automated summary

The study investigates the performance of different configurations of coils to achieve interoperability between rectangular and double-D coils recommended by SAE J2954 in an inductive charging system. Four 3D finite-element models with compensation circuits are built to perform interoperability tests at a power level of 11.1 kVA and Z3-class ground clearance. The findings demonstrate that the two different types of receivers (R and DD) can efficiently work with the general transmitter, transmitting nominal power at high efficiency even under misalignment conditions (>80%).