Electricity 101

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Electrical Engineering Fundamentals for Non-EMs

Electrical Engineering Fundamentals

For Non Engineering MANAGERS, By:

Aijaz Ali

**North Karachi Grid Station1260 MW BIN QASIM


Course OutlineSection 1: Fundamentals of Electricity & Basic CircuitsSection 2: Generators & TransformersSection 3: Power Distribution*Electrical Engineering Fundamentals for Non-EMs*


*Electrical Engineering Fundamentals for Non-EMs*IntroductionMy name isAJAZ ALIAIJAZ ALIEJAZ ALI


Introduce YourselfWhere are you from?What experience do you have in electricity?What is something interesting about yourself?What do you want to learn in this class?**Electrical Engineering Fundamentals for Non-EMs


*Electrical Engineering Fundamentals for Non-EMs*Lecture FlowElectric CircuitCurrent, Voltage and ResistanceConductor and InsulatorSeries and Parallel CircuitMagnetism and Electromagnetic InductionGenerators and TransformersPower Distribution Systems


Scientific Notation**Electrical Engineering Fundamentals for Non-EMs

PrefixSymbolDecimalPower of TenteraT1,000,000,000,0001012gigaG 1,000,000,000109megaM 1,000,000106kilok 1,000103basic unit 1millim .001103micro .000001106nanon .000000001109picop .0000000000011012


ANIMATION

Power of ten[1].swf

*Electrical Engineering Fundamentals for Non-EMs*


What is an electric circuit ?

Science electricity.wmv

Electrical Engineering Fundamentals for Non-EMs**


Water Tank A Lower TankWater Tank B Upper TankPumpValve**Electrical Engineering Fundamentals for Non-EMs


ANIMATION

WaterAnalogy[1].swf*Electrical Engineering Fundamentals for Non-EMs*


Electrical CircuitsElectrical Engineering Fundamentals for Non-EMs**


Correspond**Electrical Engineering Fundamentals for Non-EMs


Electrical Engineering Fundamentals for Non-EMsElectrical CircuitsElectrical Circuit: a complete path for current to flow.The four required parts of an electrical circuit areSource or batteryConductor or Complete pathLoad or resistanceControl device05_short_circt[1].swf


DefinitionsSource provides the electric energy to the circuit.Conductor the path for the electric energy. Load Utilizes the current to perform a useful purposeControl Device A device used to control the flow of electricity. cck-dc_1.jar



*Electrical Engineering Fundamentals for Non-EMs*What is an Electric Current?


All the matter around you is made of atoms, and all atoms are made of 3 basic particles, protons and neutrons which reside in the nucleus, and electrons which orbit the nucleus.Furthermore, all protons are exactly the same, all neutrons are exactly the same, and all electrons are exactly the same. Protons and neutrons have almost exactly the same mass. Electrons have a mass that is about 1/1835 the mass of a proton.

Atomic Theory**Electrical Engineering Fundamentals for Non-EMs


There are 2 types of electric charge, positive (+) and negative (-).Positive charge is defined as that found on protons, Negative charge is that found on electrons. Neutrons are not charged at all.

Atomic Structure**Electrical Engineering Fundamentals for Non-EMs


Atom Parts:Electrons: Negative part of an atom.Protons: Positive part of an atom.Neutrons: Negative part of an atom.The Atom**Electrical Engineering Fundamentals for Non-EMs


ANIMATIONStructure of atom031_struct_atom[1].swf1 hydrogen.swf2 copper.swf



The AtomExample: Lithium atomNeutral atom3 protons (+) = 3 electrons (-)Recall that the elementary picture of the atom is that of a nucleus with protons (positive charge), neutrons (neutral) and electrons (negative charge) orbiting the nucleus.

In a neutral atom, the number of electrons is equal to the number of protons.

FYI: Lithium is the lightest of all metals; does not occur free in nature; corrosive.**Electrical Engineering Fundamentals for Non-EMs


**Electrical Engineering Fundamentals for Non-EMs-ly Charged AtomNeutral Atom+ly Charged Atom3 protons (+) = 3 electrons (-)3 protons (+) < 4 electrons (-)3 protons (+)>2 electrons (-)


3 protons+

2 electrons2 electronsAdd 1 electron Atom becomes negatively charged3 protons+

2 electronsRemove 1 electronAtom becomes positively chargede-e - Negatively charge atom3 protons(+) / 4 electrons(-)Positively charge atom3 protons (+) / 2 electrons (-)Electric charge: An absence or excess of electrons

ANIMATION

3 current.swf



What is an Electric Current?Electric Current (I): is the flow of electrons in a conductor, measured in amperes or amps (A) by Ammeter.

Electromotive Force (emf) (E): the force applied in order to achieve the flow of electrons (V) measured in volts by Voltmeter.Electrical Engineering Fundamentals for Non-EMs**


Measuring CurrentCurrent is a FLOWTo measure a flow it must go through the device so ammeters are connected in series.ELECTRICAL ENGINEERING FUNDAMENTALS FOR NON EMs**

ELECTRICAL ENGINEERING FUNDAMENTALS FOR NON EMs

Measuring VoltageVoltage is a potential DIFFERENCE.You must have a value at two locations to measure a difference, so voltmeters are connected in parallel.ELECTRICAL ENGINEERING FUNDAMENTALS FOR NON EMs**


*Electrical Engineering Fundamentals for Non-EMs*Resistance (R):Definition: The property of a material (or conductor) to oppose the flow of current is known as resistance.An electrical circuits opposition to current flow, measured in ohms ()

Symbol for Resistance: R R = . L/AWhere, = Resistivity of the Conductor, L=Length of the Conductor and A=Area of Cross section of the Conductor.

Unit for Resistance: Ohms or s.Measured by Ohmmeterresistance-in-a-wire.swf

RESISTANCE


Conductor: a material which offers little resistance to current flowExamples:AluminumCopperSilverMost MetalsWhat is a conductor?**Electrical Engineering Fundamentals for Non-EMs


What is an insulator?Insulator: a material which offers high resistance to current flow,Examples:WoodPlasticsCeramicsRubber**Electrical Engineering Fundamentals for Non-EMs


DC Current

AC Current

Types of Current?



AC / DCAlternating CurrentElectrical Engineering Fundamentals for Non-EMsDirect Current


Direct Current Alternating Current When a current is constant with time, we say that we have direct current, abbreviated as dc. On the other hand, a current that varies with time, reversing direction periodically, is called alternating current, abbreviated as ac.

Ohms LawOhms Law: current in a circuit is directly proportional to the applied voltage and inversely proportional to the circuit resistance Mathematical Statement of the Ohms Law:I = V/ROHMS LAW.swf

ELECTRICAL ENGINEERING FUNDAMENTALS FOR NON EMs**


Watts LawElectrical PowerElectrical power is the product of voltage and current. It is denoted by P and measured in watt by wattmeter.**Electrical Engineering Fundamentals for Non-EMsVI


Ohms LawELECTRICAL ENGINEERING FUNDAMENTALS FOR NON EMs**


EnergyElectrical EnergyElectrical energy is the product of power and time. It is denoted by W and measured in Watt-hours by Energy meter. The commercial unit is Kilo-watt-hours denoted as KWH. It is a known as one unit of electricity.

Electric Bill Calculator.xlsm

**Electrical Engineering Fundamentals for Non-EMs


Ohms Law and Watts Law Formula Wheel**Electrical Engineering Fundamentals for Non-EMsFormulaWheelElectronics_gif.mht


Kirchoffs LawsThe algebraic sum of all voltages in a circuit is zeroThe sum of all currents entering a node = sum leaving the node.Series:

Parallel:



ANIMATION06_commn_typs_cir.swf07_resis_comb.swf08 resistors_series.swf09 resistors_parallel .swf10 resist_combination-1.swf11 resist_combination-2.swf



Magnetism**Electrical Engineering Fundamentals for Non-EMs


*Electrical Engineering Fundamentals for Non-EMs*ElectromagnetismAny current-carrying wire has a circulating magnetic field around it:


Magnetic Forces due to Electric Current LoopCurrent in a loop causes magnetic forces just like a magnet



Induced Current**Electrical Engineering Fundamentals for Non-EMs


Induced current (voltage) is produced by a changing of magnetic field.**Electrical Engineering Fundamentals for Non-EMs1_elecmag_induc[1].swf


Faradays Law of InductionFaraday showed that if the number of magnetic field lines (magnetic flux) passing through a loop of wire changed for any reason, a current was produced in this loop.

01 farad_exp_laws_emi[1].swf



*Electrical Engineering Fundamentals for Non-EMs*GENARATION OF ALTERNATING CURRENTac_gen[1].swf alternatormovie.avi faraday.jar04 buildturbine2[1].swf


*Induced CurrentThe next part of the story is that a changing magnetic field produces an electric current in a loop surrounding the fieldcalled electromagnetic induction, or Faradays Law*Electrical Engineering Fundamentals for Non-EMs02 self_ind_mut_ind[1].swf


TRANSFORMERSA device that transfers energy by electromagnetic inductionPrimary and secondary windings (insulated from each other electrically) are mounted on opposite sides of a ferromagnetic coreUsed to raise voltage (step-up transformer) or lower voltage (step-down transformer)Voltage is raised when the primary winding has fewer turns than the secondary winding, and voltage is lowered when the primary winding has more turns than the secondary winding transformer[1].swfElectrical Engineering Fundamentals for Non-EMs**


A Simple TransformerCOREPRIMARYWINDINGSECONDARYWINDINGElectrical Engineering Fundamentals for Non-EMs**


Transformers**Electrical Engineering Fundamentals for Non-EMs03 electmag_ind_act[1].swf


Typical Transformers**Electrical Engineering Fundamentals for Non-EMs


*Electrical Engineering Fundamentals for Non-EMs*Fundamentals Of ElectricityThree Phase (AC) Transformer ConfigurationsNote: a = Turns Ratio = Np/Ns


Power In AC Circuits*Electrical Engineering Fundamentals for Non-EMs


*2Types of Power There are three types of power in AC circuitApparent PowerActive or True powerReactive power**Electrical Engineering Fundamentals for Non-EMs


Power FactorApprent power[1].swfTrue Power [1].swfReactive power[1].swfPower factor[1].swfPower factor correction[1].swfPOWER fACTOR Mechanical work analogy[1].swf*Electrical Engineering Fundamentals for Non-EMs*


Map of KESC licensed Area**Electrical Engineering Fundamentals for Non-EMs


Generation :: HeartLDC::BrainSub-Transmission :: Sub-Arteries Transmission :: Main ArteriesDistribution :: CapillariesAn Analogy Power System vs Human BodyUSER

KESC EHT NETWORK

Karachi Electric Supply Company18 KV Generation


Generation*Electrical Engineering Fundamentals for Non-EMs*


National Grid System**Electrical Engineering Fundamentals for Non-EMs


AdvantagesProvide multiple paths between various generation sources and loadsProvide for power transfers from one geographic area to another to achieve overall system operating economicsInterconnect the bulk power facilities of individual power station/utilities so that they can better withstand major disturbances**Electrical Engineering Fundamentals for Non-EMs


AdvantagesOther advantages:StabilityLoad sharingContinuity of serviceMaintenance, breakdownEconomyCheap & efficient



National Load Dispatch Centre (NLDC)Located in IslamabadObjectives:Grid system requires a grid controller/operator system.In order to ensure the supply of energy is safe and reliable.



TransmissionTo ensure the adequacy and reliability of supply that are fundamental needs of modern society.Provides the link between electricity suppliers (KESC Generators and IPPs) and electricity consumers.**Electrical Engineering Fundamentals for Non-EMs


Transmission SystemLines/transformers operating at voltages above 100 kV are usually called the transmission system.Consists of Transmission Line and Sub-stations Transmission network of 500kV and 220kV known as National Grid.



Transmission LineOverhead LinesCableUnderground CablesOil filled cablesXLPE cablesGrid stations

**Electrical Engineering Fundamentals for Non-EMsTransmission Line


ComponentsTower support structureCross-armsConductorsInsulatorsEarth-wiresTransmission Line Components



Transmission towerWaist-Type TowerDouble Circuit Tower**Electrical Engineering Fundamentals for Non-EMs


Transmission Tower**Electrical Engineering Fundamentals for Non-EMs


Insulators**Electrical Engineering Fundamentals for Non-EMs


Grid stationSize of Grid stationDepends on transformer sizeTypical sizes132kV; 2 x 30MVA, 3 x 40MVA, 220kV; 2 x 180MVA, 2 x 250MVATypes of Grid stationConventional outdoorRequire bigger spaceGIS (gas insulated switchgear)Less spaceOutdoor or indoor**Electrical Engineering Fundamentals for Non-EMs


Outdoor Grid station**Electrical Engineering Fundamentals for Non-EMs


GIS**Electrical Engineering Fundamentals for Non-EMs


Grid station ComponentsTransformerCircuit Breaker / Switch GearIsolator SwitchesBusbarProtection Relay & Control Equipment



BRIEF INTRODUCTION TO Power Transformer **Electrical Engineering Fundamentals for Non-EMs


INTERNAL STRUCTURE OF POWER TRANSFORMER**Electrical Engineering Fundamentals for Non-EMs


INSULATORS**Electrical Engineering Fundamentals for Non-EMs


Circuit Breaker**Electrical Engineering Fundamentals for Non-EMs


*Electrical Engineering Fundamentals for Non-EMs*Power Distribution SystemsPower Distribution Systems Consist of:FeedersOver head HT / LT Lines & under ground cablesSub-stationsPole mounted Transformers (PMT)Capacitor BanksCircuit BreakersOCBs, Oil Circuit BreakersAir Circuit BreakersFuses


Distribution Sub-stationDistribution Substations (11kV)Indoor substationPole mounted substationCompact substationTransformer capacity100kVA, 250kVA, 500kVA, 750kVA and 1000kVA**Electrical Engineering Fundamentals for Non-EMs


General Distribution Sub-station*Electrical Engineering Fundamentals for Non-EMs*


Distribution Circuit Breaker**Electrical Engineering Fundamentals for Non-EMs


Sub-station**Electrical Engineering Fundamentals for Non-EMs


Indoor Sub-station**Electrical Engineering Fundamentals for Non-EMs


Pole-Mounted Transformer**Electrical Engineering Fundamentals for Non-EMs


***Headlight circuit*****Instructor:

The first graph, shows current being steady over time, as with direct current. The second shows current alternating sinusoidally over time, as with alternating current. *

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Electricity 101