Course detail
High voltages technology
FEKT-NTVNAcad. year: 2013/2014
Maxwell´s equations. Examination of the electric field. Dielectric properties of substances. Electrical discharges. Testing power sources. Measurement of high voltages and heavy currents. Overvoltages and insulation coordination in power system.
Language of instruction
Number of ECTS credits
Mode of study
Guarantor
Learning outcomes of the course unit
Prerequisites
Co-requisites
Planned learning activities and teaching methods
Assesment methods and criteria linked to learning outcomes
Requirement for the credit: min. 21 points.
Final Examination: max.60 points.
Course curriculum
2) The classification of fields and their properties. Divergence of field. Orthogonal coordinate system. The Maxwell's equations in integral and differential form. The effects of electromagnetic fields on humans.
3) The electrostatic field and his solution. The interaction of electrostatic field and dielectric. Stationary electric and magnetic fields and their solutions. The quasistationary and time-varying electromagnetic fields and their solutions.
4) The dielectric properties of materials. The division and properties of insulators. Gaseous insulators. The independent and dependent discharge. Townsend theory of impact ionization in a homogeneous field. The flashover voltage in homogeneous and inhomogeneous electric field. Paschen law. The cluster discharge and sparkle. Spark discharge. Lightning discharge and his mechanics. Channel discharge. The corona. The initial (critical) voltage corona and the corona loses on overhead lines. The ultracorona. Absorption of overvoltage waves by the corona.
5) The influence of atmospheric conditions and other circumstances on the flashover voltage. The correction of the measured values of flashover voltage on the reference standard laboratory atmosphere. Solid insulators. Electrical and thermal breakdown. Surface discharge (discharge along the surface of solid insulators). The partial discharge (discharges in insulation cavities). Determination of partial discharge current.
6) Insulators and their types. Insulator string and the voltage distribution along his axis. Uneven loading of sub-strings of insulators and technical problems with the protective armour. The rod insulators. The suspensory insulators. The bushings and the cables.
7) The testing source of high voltage (HV), their importance and distribution. The testing sources AC 50 Hz. The testing transformers. Transformer cascade. The sources of high frequency high voltage . The sources of DC high voltage.
8) The impulse testing sources. Common and standard form of the impulse voltage and current wave . The impulse voltage and current generators. The equivalent circuit and pulse wave equation. The multistage impulse voltage generator. The combined impulse voltage and current generators.
9) The measurement of high currents. The ideal and real voltage resistive, capacitive and combination divider. The resistive divider for impulse measurements the unequal distribution of voltage along the axis. The technical fix the problems "driven by field". The shunts.
10) The overvoltages in the electric power systems . The switching operations and the internal overvoltages in the electric power system. The external overvoltages caused by lightning and by the protection of grounding cable line. The grounding of towers overhead lines. The insulation coordination in the electric power systems.
11) The examples of numerical solution of electrostatic field.
12) The examples of numerical solution of stationary field.
13) The design of impulse current generator. The determination of impulse and current wave form with given constants. The determination of constants for the impulse current generator for the required shape of the impulse wave.
Work placements
Aims
Specification of controlled education, way of implementation and compensation for absences
Recommended optional programme components
Prerequisites and corequisites
Basic literature
Blažek,V.,Skala,P.: Vysoké napětí a elektrické přístroje, Laboratorní cvičení, Část I:Vysoké napětí, elektronický text, FEKT VUT v Brně,2003
Kuffel, E., Zaengl, W.S., Kuffel, J.: High Voltage Engineering: Fundamentals, Newnes, 2000, ISBN 0 7506 3634 3
Veverka,A.: Technika vysokých napětí, SNTL, 1978.
Recommended reading
Classification of course in study plans