Subestaciones Aisladas por Gas - Puerto...

Substation DesignGeneral Concepts / Electric Equipment

Colegio de Ingenieros y Agrimensores de Puerto RicoAngel T. Rodríguez Barroso and Doeg Rodríguez

August 26, 2010San Juan, P.R.

Objective

The objective of this seminar is to provide a basic guide to select the electrical equipment and other systems in order to design a substation

Substation

An assembly of equipment in an electric system through which electrical energy is passed for generation, transmission, distribution, interconnection, transformation, conversion or switching.

General ConceptsElectrical Equipment

Based on the type of equipment a Substation could be :

Outdoor type with air insulated equipmentIndoor type with air insulated equipment

Outdoor type with gas insulated equipmentIndoor type with gas insulated equipment

Mixed Technology

Outdoor type with air insulated equipment

Outdoor type with gas insulated equipment

Indoor type with gas insulated equipment

Indoor type with gas insulated equipment

Mixed

Substation ProjectConcepts

Process starts with a need1. System deficiency is identified

Equipment upgradeLoad, Short Circuit , New Technology, High Voltage

Load increaseNew Equipment

Service reliabilityGenerators, SVC, Energy Storage

Service qualityExpansion or generation addition New regulations

Substation ProjectConcepts

1.a. System Deficiency StudiesLoad FlowShort Circuit, Arc-flash & Breaker DutyGroundingInsulation CoordinationProtectionCable AmpacityPower Factor Correction ( ATP )

Substation ProjectConcepts

2. Devise a project planDevelop project scope & estimate

Description including references to other elementsSingle-line diagram (s)Estimates System and operational restrictions Time constraints

Substation ProjectConcepts

3. Formal plans and drawingsRecordsDrawings

Site information as permits, surveys, geological surveys, equipment specifications, restrictions, and legal contractsConstruction drawingsSupplier lists

Material lists and specifications

Single Line

Diagram

Single Line DiagramSingle Line Diagram

Diseño Sub-w\Single line-1a.pdfE-1 One line diagram Model (1).pdf

Preliminary DesignPreliminary Information

New or existing siteIf existing, last drawings, as-built, data collection

Design guides or standardsDescription of propertyPrevious studiesExpansion plan

SubstationBasic

Equipment

Equipment and Systems

BreakersTransformersLine & breaker switchesSurge arrestersPotential transformersCurrent transformersSubstation Bus

CapacitorsProtection & ControlMeteringCommunicationsAuxiliary systemsGrounding & Masts

Bus Arrangements

SUB-des-bus034.pdf

Bus Arrangements

Cost of configuration Cost SpaceSingle bus $1.00 P.U. 1.0Single bus with tie breaker $1.22 P.U. 1.2Main & transfer bus $1.38 P.U. 1.7Ring bus $1.15 P.U. 1.2Breaker & a half $1.63 P.U. 2.0Double bus Double breaker $2.06 P.U. 3.0

Bus CharacteristicsInsulators

Voltage Class 46 kVMaximum System Voltage 48.3 kV60 cycle wet flash over (kV) 100Impulse withstand (kV) BIL 250Leakage distance (in.) 43Dry arcing distance (in.) 17Tensile strength (lb.) 14,000Cantilever strength (lb.) 2,000

Bus CopperAluminum

StructureGalvanized structure in compliance with hurricane and seismic criteria

Equipment Insulation Surge Arresters

Functions:Limit transient surge voltages below the insulation breakdown of the equipment

Provide transient voltage protection while connected to the power operating voltage

Surge Arrester SelectionAll arresters use Zinc Oxide valves (MOV)For selecting you will need:

Power operating voltage ratingEnergy dissipation capabilityType or arrester classDo an insulation coordination study

Arrester SelectionTOV- temporary overvoltage are

cause by:Line to ground faultsNeutral lossSwitching surges

To select check:1. MCOV -Maximum Continuous

Over Voltage For grounded system

MCOV> 1.05VLG or MCOV> TOV

Ungrounded worst case is MCOV>VLL

2. Arrester Energy DissipationManufacturer provides the information but it requires a Transient Study to establish the rating

3. Type Station or intermediate

protection level, energy capability, mechanical strength, pressure relief rating

Arrester Selection4. Arrester protective characteristics

Impulse voltage levelBIL-- Basic Impulse LevelBSL– Basic Switching Surge Level

( Wave form 83% of BIL crest voltage)

Limit the lead length to a minimum

Surge ArresterPhotos

Surge-1.pdfArrester-works-3-4.pdf

Lightning Protection

Empirical Design Methods1. Fixed Angles2. Empirical Curves

Electrogeometric ModelStandard IEEE 998-1996

Shielding WiresBig substations

MastsSmall substations

They are composed of three elements:

1. Air terminals at appropriate points2. Down conductors to carry current to ground3. Grounding electrode to carry current into the earth

Lightning ProtectionMethods

MASTMETHOD.pdf

TransformersLosses

No load lossesHysteresisEddy currents

Load lossesLeakage flux & magnetic fluxRegulation

Load Tap ChangerNo load Tap Changer

TypesMultiwindingAuto transformers

lower costsmaller sizelower regulationlower losseslower impedanceno delta connection

TransformersRating

Self cooled ONAN oil natural, air natural circulation

Forced Air Rating ONAF oil natural, air forced circulation

Forced Oil Rating OFAF oil forced, air forced circulation

RatingTransformers 2.5-10 MVA

One 125% stage coolingTransformers >10 MVA

Two cooling stages 133% ONAN166% ONAN

Continuous loading with oil hot spot less than 110 degree C

Short term loading 180 degree C

TransformersCheck Rating of:

Current transformersBushingsWindingsConnectionsLoad tap changers

FailuresShort circuits

Bushing contaminationLoad tap changer

Contaminated oilContact erosionCompartment short circuits

TransformersOil Preservation

Sealed tankInert Gas

Nitrogen blanket over oilModified Conservator

Main tank is filled of oil from a conservator tank

Winding connectionsDelta-Wye

NLT, LTC location?Wye –Delta

NLT, LTC location?Delta –Delta

NLT, LTC location?Three winding transformers

NLT, LTC-location

Transformer Fire ProtectionTransformer-Prot.-2A.pdf

ElectricalTransformer Differential Protection & Fast Breaker

MechanicalBarriersDeluge-SprinklersTransformer-Prot.-1.pdfCompress-Air-FoamPressure/MechanicalProtector016.pdf

Instrument Transformers

Potential TransformersType

Insulating mediumOil -porcelainDry – composite

Medium to low voltageRated by

Rated voltage & ratio H/S BILThermal rating

Current Transformers

Type Insulating medium

Oil -porcelainDry – composite

Medium to low voltageRated by

Rated voltage & ratio H/S BILClass relay or metering

Instrument Transformers

Potential TransformersANSI/IEEE C57.13Inductive & capacitor (CVT) type

ANSI accuracy of 0.15%, 0.3%, 0.6%, 1.2%

at burdens W, X, Y, Z and ZZ (400VA at PF=.85).

Optical voltage transducer

Current TransformersANSI/IEEE C57.13Relay ClassMR 10 C200, MR 10 C400Class C is for low leakage (donut)Class T is for high leakage (bar-type)

Metering Class0.15%, 0.3%, 0.6%, Accuracy at burdensB0.1, B0.2, B0.5, B1.0 and B1.8

Optical Current transducer

Instrument Transformers CT-PT-DIS.pdf

BreakersDefinition:

Is an automatically operated electromechanical device designed to protect an electrical circuit from damage caused by a short circuit or an overload

Breakers Type

ClassificationsInterrupting medium

Air blastingOil (high & low volume)Vacuum (medium voltage)Gas SF6 (high voltage)Magnetic Air (distribution)

TankDead tankLive tank

Three Phase Closing &Single Phase Closing

Ratings – ANSI C37.06Rated voltageInsulation levelContinuous currentInterrupting current at rated

voltageTransient recovery voltageRated interrupting timePermissible trip delay

Breakers

Scan-Sub-Des\SUB-des-BR1024.pdfScan-Sub-Des\SUB-des-BR2025.pdf

Distribution-breaker.pdf

Capacitors

Benefits

Provides reactive power Power factor correction

Voltage regulationLoss reduction

Improve system capacity

Studies

Load flowShort circuit

Transient analysisHarmonics

Protection schemeMeasurements

Capacitor StudiesLoad Flow

Needs, bank capacity, location, losses, voltage regulation

Transient StudyConnection grounded or ungrounded, Overvoltage, overcurrent, insulation coordination, surge arresters.Limit overvoltage to less than 10 % of rated voltage

Short CircuitProtection, unbalance scheme

HarmonicsFilter design

Capacitors

SUB-de-cap035.pdfSUB-de-cap-stu036.pdf

SUB-de-cap-PROT037.pdf

Capacitors

EN-LV03-09_2006-wall_mounted_automatic_cap_bank.pdf

SwitchesTypes

StationTransmissionDistributionLow voltage

SwitchesType & Purpose

Single phase andGang operated three

phaseProvide isolation of:

equipment linesbuses

Allows for maintenance & testing Interruption for small currents

RatingsSpecified ANSI C37.32 & IEEE

C37.34Rated continuous currentRated maximum voltageRated short circuit-time current

(momentary)Rated mechanical operationsRated interruption capabilityRated ice breakingRated Insulation level

SwitchesMounting arrangements

Horizontal uprightSingle sideDouble sideCenter side Double side V

VerticalUnderhung or inverted

Underground

Grounding SwitchFor grounding live parts at the stationFor grounding linesSingle pole or gang operated

Switches

Switches

SwitchesTrayer.pdf

Scan-Sub-Des\SUB-DES-SW-tables.pdf

Station Power, Batteries ChargersAC Power

Two sources, emergency generator with transfer switch

Transformer cooling systemTransformer load tap changer Transformer cabinet heatersCircuit breakers stored energy

mechanismCircuit breakers cabinet heatersBuilding & Outdoor yard lightsBattery chargers & outletsBuilding mechanical systemBuilding A/C

DC ServiceTwo battery banks

Two DC distribution panelOne circuit per breaker from

each panel ( combine)For relay panel, one circuit

from each panelTwo circuit per transformer

Use IEEE Std 485 for sizing lead acid batteries

BatteriesType of batteries

VentedLead-calcium flooded cellLead-selenium flooded cellNickel-Cadmium flooded

cellValve Regulated Sealed

Design PracticesDesign a room exclusively for

batteriesDesign a room for two batteriesDesign battery room with a system to

minimize hydrogen build upProvides acid spills containmentProvide plastic shields over energize

partsProvides safety equipment Consider hydrogen sensorsConsider microprocessor controlled

chargers

CablesHigh voltage cables

Client/PREPA regulations & buy cables from approved manufacturers

Shielded cable TR-Cross-linked PolyethyleneEPR Ethylene Propylene Rubber

Low voltage Cables (600V)

Copper cable is more reliableMulticonductor, color coded cable

is preferred Practice is:PT circuits #12 AWG CUCT circuits #10 or # 8 AWG CUControl Circuits # 14 AWG CUSCADA alarms #18 AWG CU

Substation Automation & Control

Deployment of substation and feeder operating functions and applications to enhance operations and maintenance

efficiencies with minimal human intervention.

SA ArchitectureBasic Layer Architecture

Process Level ( HV Equipment)Bay Level (Protection & Control)Station level

HMI Architecture-1.pdf

Communication ProtocolsIEC 61850

Communication Networks & Systems in Substation

ScadaReal-timeSelf description

Information modelsConfiguration language

IEC-61850-AP.pdf

Distributed Network Protocol DNP3

Communication Protocol IED devices

SCADAalc-2012.pdf

Protection

Relays are devices that are connected throughout the electric power system to detect an undesirable conditions and start an action to minimize damages to the system

Protection

Protection philosophy requires a balance between redundancy and cost

The goal is to protect the system with the simplest design

The more complex the protection scheme the more probability for bad operations

ProtectionZones of protection

GeneratorsTransformersBusesTransmission LinesDistribution Lines

Zones of protectionPrimarySecondaryBack-up

Transformer ProtectionDifferentialOvercurrentOverexcitationSudden pressureGas detection

Bus ProtectionDifferentialOvercurrentBreaker failure

Protection

Line ProtectionNon-directional overcurrentDirectional overcurrentImpedancePower line carrier & pilot wireDistance & directional overcurrentCurrent differential (fiber optic channel) Phase comparison

Grounding StudyGrounding Grid General.pdfCombine-grounding-2.pdf

Line

Feed

Underground Feed

Underground FeedMuseoCar\9569-combine-car.pdf

Control &Protection

Panel

Control & Protection Panel

Visit to the SiteObserve all site advantages and constraints

Site restrictions (urban regulations)Check for future expansion constraintsHow lines and load circuits will be brought to the site and exit outAccess to the site (how to move heavy equipment)

Equipment LayoutGeneral System Layout

Diseño Sub-w\VIEQ Subst Profile 1.pdfGIS-PDF\GIS-Estudio\GIS-layout017.pdf

Post Visit to SiteUpdate project scope & get approval if

requiredUpdate estimate if required

Submit amended permits if requiredAdjust any design criteria if required

Issue instructions for long lead equipment and site studies

Equipment Lead Time

Substation Transformers 10 -16 monthsCircuit Breakers 4 – 8 monthsHigh Voltage Switches 4 – 8 monthsControl & Protection Panel 4 – 8 monthsHigh Voltage GIS Equipment 8 – 12 months Medium Voltage GIS 8 – 10 months

Developed Project Time TableExpected Service DatePermitsEquipment Procurement (transformers, breakers, etc. lead time)Power supplier requirements (PREPA and others)Client operations inputGet the approval:

SLD drawing Site Layout Detailed design ConstructionCommissioning and as-built

Substation LayoutSubstation LayoutSingle Line Diagram

Check:Numbers of breakers, disconnect switches, transformers,

auxiliaries, protective devices, lines and other equipment.Short circuit and current capacity of equipment, bus and other

equipmentCompliance with project’s scope and requirements Number of lines and load circuitsAll equipment fit within substation lot and complies with

standards

Substation LayoutFinalize design requirements

OutdoorHigh, low profile or GIS mixed

IndoorGIS or GIS mixed

System protection and power company requirementsOverhead lines & load circuits; clearancesUnderground lines & load circuits

Cables, Gas Insulated Lines, Bus (GIL, GIB)

Substation LayoutGeneral Layout

GIS-PDF\General-Layout-GIS.pdf

Questions?

Thank You

Substation DesignGeneral Concepts / Electric Equipment

Doeg RodríguezATRB, Ingenieros, CSP

787-236-6900Angel T. Rodríguez Barroso

MEC Engineering605 Condado Avenue

San Juan, P.R.787-977-5045,

angel.rodriguez@mecengpr.com

TransformersSome of the Standards

IEEE STD C57.12.2000 ANSI STD C57.12.10-1997 IEEE STD C57.12.90-1999IEEE STD C57.12.01-2000IEEE STD C57.98-1993IEEE STD C57.91-1995IEEE PC 57.119 (Draft 14.0) 2001

ReferencesANSI C37 series – Protection and Control Equipment

ANSI C57 Series – TransformersIEEE Standard 80- Substation Grounding

NEMA Standards – Electric Equipment ConstructionNational Electrical Safety Code

Electric Power Substations Engineering 2nd EditionPREPA – Manuals and Standards

Electric Power distribution Engineering 2nd EditionRUS Bulletin 1724E-300

IEEE/ANSI Standards