Contactless power transmission Maintenance-free electrical connection Let’s connect Whitepaper
Contactless power transmission Maintenance-free electrical connection Contactless power transmission over short distances is based on the inductive connection between two electric circuits. Completely dispensing with electrical contacts and the associated possibility of mechanically separating source and consumer results in a wide range of possible applications.
•• Applications with frequent plugging cycles resulting in increased maintenance work and/or a high failure rate (toolchanging systems on robots, etc.) Functional examples Contactless power transmission isn't just replacing plug connections, it's creating new ways of establishing connections. The two connection elements (the primary and secondary sides) can be brought together from any direction and power can even be transmitted when the elements are rotating.
Technology The main part of a system for contactless, inductive power transmission consists of a transformer-type arrangement of at least two coils of wire. As with traditional grid transformers (figure on left), the coil facing the electrical source of power in normal operation is known as the primary side and that facing the electrical load the secondary side.
Dependencies of system parameters Contactless power transmission is a system which depends on many variables. These are primarily the size of the air gap, eccentricity, ambient temperature, cooling, input voltage and secondary current rating. If one variable changes, the transmission behaviour changes too. For example, efficiency usually improves as the load current increases and falls when the air gap or eccentricity increases. These dependencies are of course not linear.
What needs to be noted? Due to the way it works, contactless transmission has a certain efficiency level. This means that part of the supplied power is converted into heat in the transmission system. There are therefore very few systems for higher power levels of 200 to 500 W. When installing the two transmission components, the user has to ensure that the heat produced is dissipated via metal surfaces; an additional heat sink may have to be used.
Weidmüller Interface GmbH & Co. KG Klingenbergstraße 16 32758 Detmold, Germany T +49 5231 14-0 F +49 5231 14-292083 info@weidmueller.com www.weidmueller.com We reserve the right to make technical changes .
