Post on 20-May-2018
Welcome to
EnergyProductionSystemsEngineeringThomas Blair, P.E.USF Polytechnic – Engineeringtom@thomasblairpe.com
Session 6:Electrical Systems Spring 2011
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Session 6: Electrical Systems
Electrical Systems
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIEEE defined protection numbers21 = distance relay25 = synchronism / synch check relay27 = under voltage relay32 = directional power relay40 = loss of field relay46 = current unbalance / reverse phase relay47 = phase sequence – voltage relay49 = thermal relay50 = instantaneous overcurrent relay50N = Neutral instantaneous overcurrent relay50G = Ground instantaneous overcurrent relay
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIEEE defined protection numbers51 = time delay overcurrent relay51N = Neutral time delay overcurrent relay51G = Ground time delay overcurrent relay52 = breaker59 = Overvoltage relay67 = directional overcurrent relay67V = voltage restrained directional overcurrent relay81U = under frequency relay81O = over frequency relay86 = lockout relay (mechanically latching)87 = differential current relay
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGenerator protection – two functionsSecurity of power system (primary)Protection of generator from transients (secondary)(IPP may have different priority)
Types of protection relays –Differential current protection – sense internal faults andtrip quickly – slope = operate current / restraint current.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBrushlessExciter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systemsrelaying
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsStator OC protection;Not typical, alternately, monitor stator temperature
Negative Sequence Current protection – protect rotor
Stator GF protection –Neutral impedance via distribution xfmr – OV relay onsecondary to detect GF – can not detect gnd near neutral–Third harmonic UV detect ground near neutral
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsField Ground Protection –Apply voltage to gnd on field to detect currentResistance across field to detect shiftBrushless – momentary connect gnd detection circuit viaslip rings
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systemsgnddetection
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsLoss of excitation –Loss of field, protect rotor heading during inductionoperationDetect MW & MVAR to detect absorbed MVAR
Motor protection – Detect reverse power to protectTurbine from overheat.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsRotor –Cylindrical rotor (uniform air gap or round rotor)2 & 4 pole machinesSalient pole machines6 pole and moreDC excitation of field windingVentilation channels for gas flowConstruction discussion
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsRotor inBalance Pit
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsComponents
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSize Factors –
Small machines: lower efficienciesBig machines: better efficiencies1000MW generator: almost 99%!!!Think again of magnetics and scale rulesTherefore rather one big machine than more smallermachines1% efficiency = thousands of $ per day in power plant!!!
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsModeling a synchronous generator
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPower delivered function of power angle.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsReal Power controlled by power angleReactive power controlled by voltage magnitude
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTransient Reactance -
Sudden load changes give much lower synchronousreactanceSteady state has the usual reactanceLarge machines need up to 10 secs to reach normal Xsafter transients!Good for voltage regulation at transientsBad for circuit breakage: high current
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTransformers
ConstructionK-FactorWinding configuration
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTransformers & Transformer protection –Oil filled transformer – dry type transformers
High efficiency
K rating – steal quality – core area to operate farther awayfrom knee of saturation curve
Harmonics – positive / negative / zero sequenceTriplen harmonics
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDry type transformer cooling systems.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsVoltage designations
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTransformer K factor
Defined in UL 1561Ih = rms current value (pu) at harmonic hHarmonic currents = additional heatingK-factor Xfmr > K-factor System
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsRecommended K factor for various applications
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TYPICAL LOAD k-FACTORS K-4
Electric discharge lighting K-4UPS with input filtering K-4
Welders K-4Induction heating K-4PLCs / SS controls (other than VFDs) K-4
Telecommunications equipment K-13UPS without input filtering K-13Multiwire receptacle circuits in general care areasHealth care facilities and classrooms of schools, etc. K-13
Multiwire receptacle circuits supplying inspection or testing equipment on anassembly or production line
K-13
Mainframe computer loads K-20
Solid state motor drives (variable speed drives) K-20Multiwire receptacle circuits in critical care areasAnd operating/recovery rooms of hospitals K-20
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsMagnetization current / over excitation.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTransformer connections
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTENV dry transformers in dirty, dusty environment – alsocast epoxy vs. VPI
Auto transformer – smaller adjust voltage – no isolation
Reactor – current limiting – reduced voltage start – withcapacitor for tuned filter
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDry type –epoxy cast coil
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsInstrument transformer – PT & CT
Transformer polarity
PT vs. CT defined by application
PT circuits in parallel – CT circuits in series
Do not short PT circuit – Do not open CT circuitSpecial shorting switch
120V / 5A (1A)42
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsAccuracy – XXYZZZXX = max error at conditionsY = C or T (calculated or tested)ZZZ = volts secondary at 20X rated secondary current.
Example 7:What is the max error at what voltage secondary for a;
10C200 current transformer
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems10C200 current transformer
Maximum error of 10% at 200 Volts on secondary side at20 times current (100A for 5A secondary)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPotentialTransformer
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCurrentTransformer
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsThree parts of transformer –Winding conductors, core material, insulationGrain steel – M number (lower is lower loss)
Neutral terminal / conductor = twice size phase – maintainneutral to gnd voltage < 1 V. (solid grounded system)
Arrester 5 ft from transformer (vacuum switches and/orlighting exposure)
BIL ratings of transformers
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsInsulation Test
1 min, power-frequency high potTest1.2/50 full-wave voltage impulse test
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsFull Wave vs. Chopped Wave test
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDry Type transformer BIL
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsStandard impedance < 500KVA = 3-5 %>500 KVA = 5.75 %
Fan cooling dry type = 133% rating w/ fan
Caution, temperature of conductor connection
VPI – vacuum to draw moisture out, inject epoxy, pressureapplied (inert gas) to push epoxy into winding – heat tocure epoxy
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsThermal insulation class (AMB 30C)
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AVGTMPRISE C
HOT SPOTDIFF C
HIGHESTPERM RISE C CLASS
55 10 105 A105
65 15 120 A120
80 30 150 B150
115 30 185 F185
150 30 220 H220
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsNEMA 1NEMA 3RNEMA 4NEMA 12
Dry type reduced environmental requirements and fireprotection compared with oil
Dry type available to about 15MVA
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCircuit Breaker – switch to open under current
Driven by spring action both close and tripDC power for charging motorExternal relay trip on protectionArc drawn –Air / Vacuum / SF6 / OilCoordination – discussed later in relaying section
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSpecial considerations:Need DC to trip / close – battery fedSynchronizingDead bus transferMotor bus transfer – reclosing
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGrounding –Ungrounded / low impedance / high impedance / solidgrounded
Advantages / disadvantages
Ungrounded – reliable – first GF no tripHigh transient voltageDifficult to locate groundGround detection via open delta transformer (DRAW)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGrounding –High impedance ground (10A) – low damage, can alarm onground increase reliability,Need sensitive relay to detect and locate groundTransient less than ungrounded but higher than lowimpedance ground.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGrounding –Low impedance ground (400A) – easily detected, higherdamage, easily located, transients less, trip on fault,reduced security
Solid grounded – most damage, easily detected, easilylocated, transients minimum, trip on fault, reducedsecurity
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDifferential protection on delta wye may need wye deltaconnected CTs to compensate for 30 degree phase shift.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCan add grounding transformer to ground a delta fedsystem
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSystem-grounding design considerations –Three levels of conductor insulation for MV cables: 100,133, and 173% levels.The solidly grounded system permits the use of 100%insulation level.If fault cleared within 1 hour, 133% insulation level shouldbe specifiedIf fault cleared more than 1 hour, 173% voltage levelinsulation should be used
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGrounding –Adequate ground-return conductors to minimize theinherent step-and-touch potentials w/ solidly groundedsystems Instantaneous ground fault relaying to minimizethe fault duration.
See the NEC NESC and IEEE Std 80
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsAll non -current-carrying metallic structures areinterconnected and grounded.Purpose:Minimize potential difference between metallic membersMinimizing the risk of electric shocks to personnelImprove protective device performanced) To avoid fires in combustible atmospheres
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsInductance of ground path
L = 4 X 10-7 ln ( D / r’ ) H/m
Therefore, L increases as D increases
VD increases as D increases &Current tends to flow in closest cond.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTwo or more rods suggestedDistance between rods must be Lr1 + Lr2Example two 8 ft rods, should be 16ft distance(Numerous books and articles show the distance betweentwo standard length 8 or 10 ft rods to be 3 m (10 ft), whichis incorrect.)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsImpedance depended on IEEE 80 Calc.Larger substations and generating stations < 1WSmaller substations and for industrial plants < 5WNEC, Article 250, approves the use of a single electrode, if< 25W
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsProtective relaying & coordination:
Two functions – Protection of equipment (secondary)Security of system (primary)
Trip when faulty condition present AND don’t trip whenfaulty condition not present
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsBalance of following concepts:Reliability – Relay system trip when fault exists inprotective zoneSecurity – Relay system trip only when fault exists inprotective zoneSelectivity – Relay system should trip minimum equipmentto remove faultSpeed – Relay system remove fault fast to minimizedamage and arc flash incident energy.Simplicity – minimum amount of equipment – maximizereliabilityEconomics – Reasonable cost
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsMost common – 50, 51, 27, 59, 81O, 81U, 87
PTs and CTs feed relays
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsGround fault –Unbalanced current – not easily detected by phase relay,use sensitive ground fault relayFor grounded system, use 50G or 51G as shown below.For ungrounded system use broken delta with 59 relay.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPhase Faults:Line to Line, Line to Ground (solid system), and 3 phasefault detection. 50 and/or 51 detect.
Overvoltage (59) – typically used on neutral or grounddetection systems
Frequency (81O & 81U) – indication of system transient.Protection during “Islanding”
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDifferential relay (87) –Detect internal fault quickly – ignore external fault reliablyMay be more than just 2 winding device (i.e. 6 CT inputs)
Overcurrent (50/51) both phase and ground detection –51 device to allow for coordination between elements
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDirectional overcurrent (67) –Control flow of power – prevent motoring of generatorNeed VT & CT to polarize relay
Distance relay (21), trip if fault in zone 1, backup for zone2, 3. Needs VT & CT input. Common application is lookingback into generator impedance (quick trip of breaker forgen fault).
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSynchronizing relay (25) -
Both Synchronizing and Synch check
Magnitude, angle, rotation, frequency
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTypical Relay& ProtectionOne-lineDiagram
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsShort Circuit Current Calculations
Purpose- Present considerations of short-circuit currentcalculations;- Illustrate common methods for calculations;- Furnish typical data used in calculations.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsRotating Machine Equivalent Circuit
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsXd ’ ’ - subtransient reactance – (0 < t < 0.1s )Xd ’ - transient reactance – (0.1 < t < 0.5 to 2.0s )Xd - synchronous reactance – (0.5 to 2.0s < t ) SteadyState
When given Xdv ’ ’ – (at rated voltage, saturated, smaller)and Xdi ’ ’ – (at rated current unsaturated, larger), use Xdv’ ’
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsXd ’ ’ - subtransient reactance – (0 < t < 0.1s )No Value for Xd ’ and Xd as motor only contributes SCA forinitial cycles.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsUtility normally shown with as infinite bus with fixedimpedance.For MV & HV systems, R usually ignoredFor LV system R includedArc Resistance not zero
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSelect location for purpose of calculation- Establish simple modelRecognize restraints of modelAdjust model if assumptions too restraining
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsStep 1: Prepare system diagramsStep 2: Collect and convert impedance dataStep 3: Combine impedancesStep 4: Calculate short-circuit current
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsWye Delta Conversion
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDelta Wye Conversion
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPer Unit Calculations
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPer Unit Calculations
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systemsexample
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSoftware Model
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSubtransientResult
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSteady state result
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsFault at MCC1
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCorrect Phase TCC
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCorrect GroundTCC
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIncorrect PhaseTCC
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIn-Plant Electrical Distribution SystemEnsure reliability of systemEither higher spinning reserve – high failure rateLow spinning reserve – low failure rate
Without reliable distribution system, plant operation cannot be reliable.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDistribution system design standards:IEEE Color Books
EMERALD BOOK IEEE Std 1100-1999 IEEE RecommendedPractice for Powering and Grounding Electronic Equipment
RED BOOK IEEE Std 141-1993 IEEE Recommended Practicefor Electric Power Distribution for Industrial Plants
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDistribution system design standards:IEEE Color Books
GREEN BOOK IEEE Std 142-1991 IEEE RecommendedPractice for Grounding of Industrial and CommercialPower Systems
BUFF BOOK IEEE Std 242-2001 IEEE RecommendedPractice for Protection and Coordination of Industrial andCommercial Power Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIEEE Color Books
BROWN BOOK IEEE Std 399-1997 IEEE RecommendedPractice for Industrial and Commercial Power SystemsAnalysis
ORANGE BOOK IEEE Std 446-1995 IEEE RecommendedPractice for Emergency and Standby Power Systems forIndustrial and Commercial Applications
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsIEEE Color Books
GOLD BOOK IEEE Std 493-1997 IEEE RecommendedPractice for the Design of Reliable Industrial andCommercial Power Systems
BRONZE BOOK IEEE Std 739-1995 IEEE RecommendedPractice for Energy Management in Industrial andCommercial Facilities
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsNFPA HFPE and Society of Fire Protection Engineers SFPEHandbook of Fire Protection EngineeringNFPA 101H, Life Safety Code HandbookNFPA 20, Centrifugal Fire PumpsNFPA 70, National Electrical CodeNFPA 70B, Electrical Equipment MaintenanceNFPA 70E, Electrical Safety Requirements for EmployeeWorkplacesNFPA 72, National Fire Alarm CodeNFPA 75, Protection of Electronic Computer/DataProcessing Equipment
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsDifference between
Code (Stand alone)Standard (Shall)Recommended Practice (Should)Guide (May)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSystem Planning.
a) Load development & schedule1) Peak load requirements2) Temporary power3) Timing
b) Load variations – load growth.
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systemsc) Nature of load in terms of its occurrence
1) Continuous2) Intermittent3) Cyclical4) Special or unusual loads5) Combination of above
d) Expected power factor
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsCost vs. Reliability- Radial system- Primary-selective systemSecondary selective system
- Simple spot network system- Secondary-network system
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSimple Radial System
- Fault in device = power outage- Maintenance difficultOperation simple
Low capital costLarger installations where outage time not critical
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsExpanded Radial System –
Fault in main feed = power outageFault in xfmr = reduced outage- Maintenance difficultOperation simple
Low capital cost
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsPrimary Selective System –
-Protection against loss of primary feed-Still Xfmr Dependent-Primary source Maintenance easier-Slightly higher capital cost
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsProtection against loss of primary feedStill Xfmr DependentSlightly higher capital costOperation slightly more difficultOpen loop operationMore reliable with loop closed and directional protectionbut two devices to isolate fault
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsProtection against loss of primary feed and primary xfmrMaintenance of xfmrHigher capital costOperation more difficultSize xfmr & breaker for full load
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsSimilar to secondary selective systemXfmr sized for only one busN+1 transformer neededOperation difficult – interlock so xfmr only feed one bus ata timePossible retrofit
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsRequires Network ProjectorTrip on reverse powerHigh reliabilityHigh cost
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsTwo devices to isolate faultTrip on reverse powerHigh reliabilityHigher cost
142
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsExpected daily and annual load factor:
143
Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsLarge motor-starting requirements
1) HP, FLA, LRA2) synchronous - induction3) Voltage4) Starting requirements
Special or unusual loads such as1) Welding2) Induction heating or melting3) Portable (Crane)
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical SystemsHarmonic-generating loads
1) VFDs2) Arc discharge lighting3) Arc furnaces4) SCR controlled loads
Special power quality requirements for sensitive or criticalloads
1) Data processing operations2) Special machines (Semiconductor process)3) Continuous process loads
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Energy Production EngineeringThomas Blair, P.E.
(tom@thomasblairpe.com)
Electrical Systems
To be continued …
EnergyProductionSystemsEngineering
Thomas Blair, P.E.USF Polytechnic – Engineeringtom@thomasblairpe.com
End of Session 6:Electrical Systems
Spring 2011