Page 27 - PEN eBook May 2022

Design MAGNETIC

As shown in Figures 4 and 5, the
conventional flat-spiral-coil–pair
configuration achieves a peak

efficiency value of about 68% (without
ferrite and when the coil pairs are
well-aligned) at a frequency of
490 kHz. Nevertheless, the efficiency
value decreases rapidly as the
misalignment between the transmitter
coil and the receiver coil increases.
The IH-WPT configuration archives a
peak efficiency value of about 72% at

the frequency of 530 kHz. Figure 5: Effect of misalignment on power-transfer efficiency

Conventional silicon-based switching power devices (such as power MOSFETs, IGBTs, and power SCR-Based Pulse
diodes), as well as common inverter and rectifier circuit configurations (such as half-bridge and
H-bridge inverters and rectifiers) can operate effectively inside this frequency range, providing high Generator for Power
power-transfer–efficiency values.
Choke Measurements

Due to its particular and unique geometry, the IH-WPT configuration offers the benefit of easily
achieving and maintaining the alignment between the transistor coil and the receiver coil. The
configuration shown in Figure 1c, the flat-spiral coil placed inside a helical coil, offers a much lower Up to 10 kA
efficiency compared with the other two configurations.

A new SCR-based pulse generator has been
In conclusion, we can say that the proposed IH-WPT configuration consisting of one helical coil
inside another larger helical coil offers two main advantages over the conventional flat-spiral- developed and tested on various inductive
coil–pair configuration. The first advantage is that it provides higher wireless-power-transmission–
efficiency values, while the second advantage is that it can easily achieve and maintain alignment power components by Bs&T Frankfurt am Main

between the transistor coil and the receiver coil.
GmbH. The pulse generator has some unique

properties that benefit from the high-pulsed-

For More Information
current–handling capabilities of SCRs, and it

offers some major advantages compared with
▶ Analysis and Evaluation of Air-core Two-coil Wireless Power Transfer System

Configurations IGBT-based systems.

▶ Wireless power transfer By Christian Teske, founder and CEO of Consolidated Electrodynamics Limited,
and JC Sun, founder of Bs&T Frankfurt am Main GmbH

42 MAY 2022 | www.powerelectronicsnews.com MAY 2022 | www.powerelectronicsnews.com 43