Physics and Diagnostics of Insulations

Ideal and real dielectrics, electrical field in real dielectrics. Electrical phenomena in real dielectrics: conduction, polarization and breakdown processes and their properties and interactions.

Conduction, elementary polarization processes, relation between the macro- and micro properties. The effect of polarization processes: permittivity and dielectric loss. Properties of polarization: polarizability, polarization vector, temperature and frequency dependence of polarization. The complex permittivity. Polarization spectrum and its investigation.

Breakdown properties, dielectric strength. Breakdown mechanisms in gaseous, liquid and solid insulation materials. Statistic theory of breakdown.

Physics of partial discharges: corona, internal and surface discharges. Breakdown channel development, electrical and water treeing. Measurement methods and processes. Evaluation of statistical methods by computer, application of artificial intelligence methods, expert systems and neural networks.

Ageing of insulating materials, chemical and physical processes. The rule of temperature, field strength and environmental stresses in ageing. Electrical and thermal ageing laws. Investigation of ageing models.

Relation of deterioration processes and dielectric properties. Modeling of dielectric processes and dielectric properties. Electrical model of dielectrics and their limitations.

Diagnostic methods of electrical insulations. Methods based on current, voltage and loss factor measurement.