Dielectric, mechanical and environmental performances of the electrical insulation of low voltage rotating machines varnished with different techniques

The aim of our study is to evaluate the potential of using a new technique for impregnating low voltage electric motors. In this communication, a comparative study is performed with two different coating techniques: the conventional technique using primary (enamel) and secondary (varnish) insulations and an alternative technique that uses self-bonding wires which only require a very fast polymerization by current flow. We estimate the environmental impact of these two techniques and the dielectric performance of the insulation system. Indeed, an eco-designed device should have a better impact on the environment but with the same properties. Regarding the dielectric and mechanical properties, we have measured the dielectric strength, the lifetime under pulses voltage, the polarization index and the bonding strength which are crucial data for the insulation system of these motors. Meanwhile, an environmental assessment that can simultaneously take into account 11 impacts on different media: ground, water, atmosphere, is developed. With dielectric performances almost identical, the use of self-bonding wires significantly reduces the environmental footprint attributed to the impregnation process.