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wire 2012: Leverage Electromagnetic Phenomena Enamelled wire and electrical coils are the core element of electrical engineering

The wire, cable and wire-processing industry and the wire 2012 trade fair from 26 to 30 March in Düsseldorf

Copper and aluminium wire is indispensable in the production, transmission and utilization of electricity. A special version, enamelled or winding wire, is processed into coils, which then have a key function in electrical components. Among others, the 2012 wire trade fair, which is being held from 26 to 30 March in Düsseldorf, will present machinery for manufacturing wire of all kinds, including enamelled wire and its further processing into coils.

Wire and electricity

The outstanding properties of copper and aluminium wires include their good electrical conductivity, which is why they are very often used as electrical conductors. While the electricity is passing through, the electron movement leads to the formation of a magnetic field around the wire. If the wire is wound up into a coil, the magnetic field of every individual winding strengthens the field of the next winding and the magnetic flux increases so that one large magnetic field is created. The most important physical characteristic of these coils is their inductivity in other words their capability, triggered by a magnetic field in their own coil windings, to generate an electric voltage.

Enamelled wire

For tasks in which electromagnetic interaction plays the decisive role, with just a few exceptions, a specific, copper wire described as a winding, enamelled, magnetic or electrical wire is used, which has a fine electrically insulating enamel coating, and depending on the application, can be 0.02 mm to 2.0 mm in diameter. The advantage of copper is that in terms of conductivity it requires the least space, can be easily shaped and is easy to solder or weld, which is very important for contacts. The function of coils made from this copper essentially depends on the quality of the wire and the insulation coating, which is designed to prevent a short-circuit between the electricity-carrying coil windings. The coils can, but must not essentially have an insulator, as their task is mostly to simply hold the wire firmly in place.

Enamelled wire and coils wound with it

Wire coils are central elements of electromagnets, electric motors, transformers and power generators where they function as actuators; a further area of application is measuring appliances and aerials, where the coils are used as sensors. The specifications and dimensions of the coils extend from just a few millimetres right up to units weighing several hundred tons. In a wind turbine with a nominal capacity of 5 MW, for example around 6.5 t of enamelled wire is installed, mainly in the generator and transformer.

As is evident from the “Kupfer in der Elektrotechnik – Kabel und Leitungen” (“Copper in electrical engineering - cable and wires”) brochure published by the German Copper Institute (Deutscher Kupfer-Institut – DKI), smaller and all other coils wound with thin wire (for high voltages ) are made of round wire, while for stronger amperage, flat rolled profile wire is mostly used as it can be wound more easily and has a better fill factor, in other words it enables the more effective utilization of available space. For very strong currents and higher frequencies, strands consisting of several wires are used as a conductor. Specific enamels can be mainly used as insulation material for winding wire, while for very thick wires paper or both can also be used. The wire diameter and method according to which the wire– or with larger coils the strand – is wound into a coil or wound onto a coil carrier or drum, along with the geometric structure of the winding have a major influence on the physical properties of the coil and thus on the performance of the product in which it is installed.

Electrification: automobile technology and “energy turnaround”

The most striking trends and tendencies in industry and technology are the increasing linking of mechanics, electrics, software and modern communication technologies coupled with the simultaneous miniaturization of all components and also the urgent need to increase efficiency in connection with energy, raw and operating materials. In relation to wire products this has meant a reduction in the geometric dimensions. Examples of this development are the activities in the automobile sector, where wires and cables have always played a decisive, important role. The constantly changing requirements placed on drive systems, specifically on electric motors, energy supply, energy distribution and on energy storage systems for motor vehicles as well as on the numerous electrical engineering actuators along with the increased networking with communication systems, can only be achieved through high-quality wire and cable products.

Cable manufacturers are in the process of developing weight-optimized cable systems for vehicles with conventional but also alternative drive systems as well as on-board power supplies for high-voltage. In a report by the Copper Development Association (CDA) published in the run-up to the Detroit Motor Show in early 2011 entitled “Copper at the Heart of it All” there is reference to the general trend towards bringing vehicles with electric or hybrid drive systems onto the roads and to the fact that in these vehicles “There is a lot of new technology, which means a lot of copper cable”. The article quotes Bob Weed, Vice President of original equipment manufacturing for the CDA, who has studied electrification since the early days of vehicles. According to him, the average car produced in North America contains 50 – 55 pounds of copper. “In an electric car, that amount is closer to 150 –180 pounds,” he then added. “More than two thirds of the copper will be found in a car’s wiring harness and electrical components, which will naturally increase as vehicles rely more on electric power.” Bob Weed expects that by the year 2015 one tenth of all vehicles sold in the USA could contain an electric drive system in some form or other. Due to the weight of the copper and the trend in copper prices, many scientists are also working on replacing the copper cables used for vehicles’ power supply with aluminium conductors.

These electric and hybrid vehicles are in turn dependent on a power supply, the details of which are currently being discussed in many areas under the “energy turnaround” umbrella term. A key component of this concept is the use of renewable energy sources with de-central, intelligent controllable networks for the transmission of electricity. The report entitled “Renewable Energy & Grid Developments Provided by CRU”, which the trade association of International Cablemakers Federation (ICF) published in the “ICF-Newsletter” in July 2011, explains that these technologies will require more cable per electricity unit than we were previously familiar with in conventional technology.

Wire, electrical coils and the wire 2012 trade fair

Be it for the transmission of electricity, electronic data or mechanical energy: wire and the products made from it such as cables, ropes, springs, screws, meshes, grids or even electrical coils have an indispensable, important function in all areas of daily life. In interaction with electrical coils wire also makes a considerable contribution to the efficient utilization of electric power.

The leading, international trade fair for the wire and cable industry, wire, will be providing information about future-oriented technologies when it is held for the 13th time in Düsseldorf in March 2012. There, among others, machines for all process stages ranging from wire manufacture through to enamelled wire production right up to electrical coil winding but also wire and cable products, will be presented.

Your press contacts in 2012:

Tel.: +49 (0)211/4560-541/-544

Fax: +49 (0)211/4560-87 541/-87 544

E-Mail: HartmannP@messe-duesseldorf.de

E-Mail: KleophasvandenBongardtK@messe-duesseldorf.de

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