The field of nanodielectrics has had a significant impact on voltage endurance characteristics of electrical insulation. Improved time-tobreakdown behavior, resulting in reduced aging of insulation, and enhanced thermal stability are of considerable importance in industrial applications. This chapter discusses several specific aspects of nanodielectrics and their role in the future of electrical insulation and dielectric sciences.
IntroductionOne should not forget that power technology-high-voltage apparatus, transmission, and most electrical components-could not exist without satisfactory electrical insulation. It is a challenging task to design and optimize an electrical insulation system while energy demand, voltage levels, and operating temperatures are either increasing in conventional applications or decreasing to cryogenic temperatures in superconducting applications. In addition, these * Research sponsored by the U.S. Department of Energy-Office of Electricity Delivery and Energy Reliability, Superconductivity Program for Electric Power Systems under contract DEAC05-00OR22725 with Oak Ridge National Laboratory, managed and operated by UT-Battelle, LLC.2 electrical components and equipment sizes are becoming smaller and more compact than conventional devices, placing greater demands on the insulation. New insulation materials are expected to have better endurance and to have better reliability than their conventional counterparts. Recent developments in composite materials filled with nanometer-size particles (defined here as particles in which at least one dimension is in the range 1-100 nm) have shown some interesting results, creating a new research field in electrical insulation being referred to as nanodielectrics (Lewis 1994;Lewis 2006;Nelson and Fothergill 2004;Cao et al. 2004).A detailed description of dielectrics for high-voltage applications was provided in earlier work by Dakin (1978). In this chapter, our discussion will focus on recent developments in the field of nanodielectrics. Only solid insulation materials composed of nanoparticle-loaded polymers will be considered here. The chapter is organized as follows. Different aspects of the nanodielectrics will be considered starting with the background and challenges faced in synthesizing nanocomposites. Some of the significant advantages of the nanodielectrics and their impact on electrical insulation industry are then discussed in the context of dielectric breakdown and voltage endurance. Nanodielectric applications at high and low temperatures together with specific device/component applications are discussed as well.