Presentation on theme: "High Voltage Engineering (Advanced)"— Presentation transcript:
1 High Voltage Engineering (Advanced) Lecture # 1 Basics of High VoltageArsalan A RahimUniversity of Engineering & Technology Lahore, Pakistan
2 All books available for Download at ep.nge.com.pk (Course Page) Course BooksHigh Voltage and Electrical Insulation Engineering (June 2011 Edition) by Ravindra & Wolfgang (IEEE Press)High Voltage Engineering Fundamentals (2nd Edition) by E.Kuffel, W.S.Zaengl, J.KuffelReference BooksAdvances in High Voltage Engineering (IET) Edited by A.Haddad & D.WarneHigh Voltage Engineering by C.L. WadhwaHigh Voltage Engineering by M.S.Naidu (4th Edition)All books available for Download at ep.nge.com.pk (Course Page)
3 Why High Voltage (Engineering)? It’s the knowledge of the behavior of dielectrics (insulator) — electrical insulation when subjected to high voltageNo concept of a complete Insulator – Even a good Insulator can conduct under High VoltagesResult is to minimize the volume of the electrical insulation requirements and trouble-free life of high voltage apparatus.A totally different Domain (Engineering) when High Voltage are applied. Stray Capacitances & Inductances come into play.
4 Basic Definitions to Start With ElectronProtonIonIonizationElectric ChargeSpace ChargeVolume Charge Density ρvElectric DischargeElectric & Magnetic FieldElectromagnetics
5 Di-Electric & Electric Material What the difference between these ?Electric Material – capable of developing (conducting) electric charge or currentDi-Electric Material – not capable of developing (conducting) electric charge or current but admits electrostatic and magnetic lines of forceDi-Electric Material Properties– Relative Permittivity εr , Type of Material & Amplitude of Voltage Applied
6 Electrical BreakdownFailure of Electrical Insulation Properties (flow of current) of an Insulator or Di-electricLocal Breakdown confined locally to apart of an Insulator (Partial Breakdown)Global Breakdown complete rupture or failure of insulator properties (Electrical Breakdown)
7 Corona: Streamer: Partial Electrical Breakdown (discharge) Stable Partial Breakdown (PB) in Gaseous Di-electricsTypes: Audible & Visible CoronaStreamer:Extension of Corona at DistanceShower of Discharge (Streamer Corona)Example: Discharge of Cloud (Lightning)
8 Aurora:Luminous phenomenon consisting of streamers or Arches of Light at Polar RegionsExplained under “Faraday’s Glow”Atoms in Ionosphere stuck by High Energy Electrons Coming from Sun (cosmic Radiation)Aurora Australis (Southern Hemisphere)Aurora Borealis (Northern Hemisphere)
10 Di-electric Property: Capacitance Is the field between the plates of a Capacitor Uniform?Permittivity of a Di-electric is Constant ?Stray CapacitanceHow to minimize it?
11 Electric FieldElectric Charge is considered static when there is no movement of chargeField produced by Static charge or Direct Voltage is known as Electro-static fieldField produced by power frequency Alternating voltage is known as quasi-stationary Electric fieldElectric Field Intensity
12 Dielectric Breakdown depends on Composition of dielectric material, presence of impurities imperfections in the dielectricPressureHumidityTemperatureElectric field configuration (shape of the electrodes, their size and gap distance)Electrode materialDurationMagnitude and the waveform of the applied voltage