THE WIRELESS ELECTRIC POWER TRANSFER SYSTEM

Abstract

The equipment powered by built-in batteries has become widespread: unmanned aerial vehicles,
portable radios, tactical flashlights, electric vehicles, etc. Charging of batteries is often
carried out in a contact way – by connecting a power source by means of a detachable connection.
This requires the presence of technical personnel for maintenance and replacement of batteries;
requires the organization of protection of the battery connection from environmental influences
(moisture, dirt, etc.), as well as protection against electric shock to personnel. The purpose of the
research is to develop technical means of wireless transmission of electrical energy, which will
eliminate the use of detachable connections, improve electrical safety, and, most importantly, will
make it possible to make the charging process automatic. The results of the work are relevant for
the implementation of automatic cargo delivery systems using unmanned vehicles; for the implementation
of automatic charging systems for urban electric vehicles; for the implementation of automatic charging of unmanned land, floating (including underwater) and aircraft (reconnaissance,
patrol, etc.). The design of a wireless power transmission system with a power of up to
250 W, suitable for charging 6-cell lithium batteries, is described. The system works with coils
with a diameter of 200 mm, full operability is maintained for a distance between the coils centers
up to 100 mm. The efficiency in the entire range of operation modes is not lower than 74%, when
measured from the 220 V mains to the output to the battery. When designing, the goal was to minimize
the weight of the receiving part to facilitate its installation on the UAV and minimize the
impact on its thrust-to-weight ratio.