Siemens is developing an insulator to make generators more efficient. The electrical energy in generators occurs in copper bars insulated against high electrical voltages with thick layers of plastic. New materials would enable a thinner design for the insulators, freeing up space for thicker bars to generate more energy and to adapt a generator to a more powerful turbine.
Siemens Corporate Technology is working with industry partners to develop new insulators with nanoparticles. The materials have been effective in the laboratory. The next step is to ready the technology for the market.
The voltage between the copper bars of a generator can be tens of thousands of volts. This ionises the air, leading to partial discharges which attack the copper conductor?s insulation and produce erosion channels that propagate in the protective coating. If they reach the metal, these channels can trigger short circuits. This is why particles of mica are added to the plastic on the insulator. As the erosion channels have to go around the tiny scales of mica, they take longer to reach the copper, and the insulator can withstand higher voltages.
Siemens is studying the insulating effect of nanoparticles made of silicates. At a few millionths of a millimetre, the tiny balls have a large surface area and lengthen the detour for the erosion channels. Insulators to which the nanoparticles have been added, in addition to the mica scales, exhibit up to 10 times more resistance to partial discharges in the laboratory. For their next step, researchers hope to use nanoinsulators to make the insulation layers, some of which are centimetres thicker.
Source: Siemens Research News