Substation Design General Concepts / Electric Equipment Colegio de - - PowerPoint PPT Presentation

Substation Design

General Concepts / Electric Equipment

Colegio de Ingenieros y Agrimensores de Puerto Rico Angel T. Rodríguez Barroso and Doeg Rodríguez August 26, 2010 San 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 Concepts Electrical Equipment

Based on the type of equipment a Substation could be :

Outdoor type with air insulated equipment Indoor type with air insulated equipment Outdoor type with gas insulated equipment Indoor 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 Project Concepts

Process starts with a need

• 1. System deficiency is identified

Equipment upgrade

Load, Short Circuit , New Technology, High Voltage

Load increase

New Equipment

Service reliability

Generators, SVC, Energy Storage

Service quality Expansion or generation addition New regulations

Substation Project Concepts

1.a. System Deficiency Studies

Load Flow Short Circuit, Arc-flash & Breaker Duty Grounding Insulation Coordination Protection Cable Ampacity Power Factor Correction ( ATP )

Substation Project Concepts

• 2. Devise a project plan

Develop project scope & estimate

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

Substation Project Concepts

• 3. Formal plans and drawings

Records Drawings

Site information as permits, surveys, geological surveys, equipment specifications, restrictions, and legal contracts Construction drawings Supplier lists

Material lists and specifications

Single Line

Diagram

Single Line Diagram

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

Preliminary Design

Preliminary Information New or existing site

If existing, last drawings, as-built, data collection

Design guides or standards Description of property Previous studies Expansion plan

Substation Basic

Equipment

Equipment and Systems

Breakers Transformers Line & breaker switches Surge arresters Potential transformers Current transformers Substation Bus Capacitors Protection & Control Metering Communications Auxiliary systems Grounding & Masts

Bus Arrangements

SUB-des-bus034.pdf

Bus Arrangements

Cost of configuration Cost Space

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

Bus Characteristics

Insulators Voltage Class 46 kV Maximum System Voltage 48.3 kV 60 cycle wet flash over (kV) 100 Impulse withstand (kV) BIL 250 Leakage distance (in.) 43 Dry arcing distance (in.) 17 Tensile strength (lb.) 14,000 Cantilever strength (lb.) 2,000 Bus Copper Aluminum Structure Galvanized 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 Selection

All arresters use Zinc Oxide valves (MOV) For selecting you will need: Power operating voltage rating Energy dissipation capability Type or arrester class Do an insulation coordination study

Arrester Selection

TOV- temporary overvoltage are cause by:

Line to ground faults Neutral loss Switching 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 Dissipation

Manufacturer 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 Selection

• 4. Arrester protective characteristics

Impulse voltage level BIL-- Basic Impulse Level BSL– Basic Switching Surge Level ( Wave form 83% of BIL crest voltage) Limit the lead length to a minimum

Surge Arrester

Photos Surge-1.pdf Arrester-works-3-4.pdf

Lightning Protection

Empirical Design Methods

• 1. Fixed Angles
• 2. Empirical Curves

Electrogeometric Model Standard IEEE 998-1996 Shielding Wires Big substations Masts Small substations They are composed of three elements:

• 1. Air terminals at appropriate

points

• 2. Down conductors to carry

current to ground

• 3. Grounding electrode to

carry current into the earth

Lightning Protection

Methods MASTMETHOD.pdf

Transformers

Losses

No load losses Hysteresis Eddy currents Load losses Leakage flux & magnetic flux Regulation

Load Tap Changer No load Tap Changer

Types Multiwinding Auto transformers lower cost smaller size lower regulation lower losses lower impedance no delta connection

Transformers

Rating 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

Rating Transformers 2.5-10 MVA One 125% stage cooling Transformers >10 MVA Two cooling stages 133% ONAN 166% ONAN Continuous loading with oil hot spot less than 110 degree C Short term loading 180 degree C

Transformers

Check Rating of: Current transformers Bushings Windings Connections Load tap changers Failures

Short circuits Bushing contamination Load tap changer

Contaminated oil Contact erosion Compartment short circuits

Transformers

Oil Preservation

Sealed tank Inert Gas Nitrogen blanket over oil Modified Conservator Main tank is filled of oil from a conservator tank

Winding connections

Delta-Wye NLT, LTC location? Wye –Delta NLT, LTC location? Delta –Delta NLT, LTC location? Three winding transformers NLT, LTC-location

Transformer Fire Protection

Transformer-Prot.-2A.pdf Electrical

Transformer Differential Protection & Fast Breaker

Mechanical Barriers Deluge-Sprinklers Transformer-Prot.-1.pdf Compress-Air-Foam Pressure/Mechanical Protector016.pdf

Instrument Transformers

Potential Transformers

Type Insulating medium Oil -porcelain Dry – composite Medium to low voltage Rated by

Rated voltage & ratio H/S BIL Thermal rating

Current Transformers Type Insulating medium Oil -porcelain Dry – composite Medium to low voltage Rated by

Rated voltage & ratio H/S BIL Class relay or metering

Instrument Transformers

Potential Transformers ANSI/IEEE C57.13

Inductive & 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 Transformers ANSI/IEEE C57.13

Relay Class MR 10 C200, MR 10 C400 Class C is for low leakage (donut) Class T is for high leakage (bar-type) Metering Class 0.15%, 0.3%, 0.6%, Accuracy at burdens B0.1, B0.2, B0.5, B1.0 and B1.8

Optical Current transducer

Instrument Transformers

CT-PT-DIS.pdf

Breakers

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

Breakers Type

Classifications

Interrupting medium

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

Tank

Dead tank Live tank

Three Phase Closing & Single Phase Closing

Ratings – ANSI C37.06

Rated voltage Insulation level Continuous current Interrupting current at rated voltage Transient recovery voltage Rated interrupting time Permissible trip delay

Breakers

Scan-Sub-Des\SUB-des-BR1024.pdf Scan-Sub-Des\SUB-des-BR2025.pdf Distribution-breaker.pdf

Capacitors

Benefits Provides reactive power Power factor correction Voltage regulation Loss reduction Improve system capacity Studies Load flow Short circuit Transient analysis Harmonics Protection scheme Measurements

Capacitor Studies

Load Flow

Needs, bank capacity, location, losses, voltage regulation

Transient Study

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

Short Circuit

Protection, unbalance scheme

Harmonics

Filter design

Capacitors

SUB-de-cap035.pdf SUB-de-cap-stu036.pdf SUB-de-cap-PROT037.pdf

Capacitors

EN-LV03-09_2006- wall_mounted_automatic_cap_bank.pdf

Switches

Types

Station Transmission Distribution Low voltage

Switches

Type & Purpose Single phase and Gang operated three phase

Provide isolation of: equipment lines buses Allows for maintenance & testing Interruption for small currents

Ratings

Specified ANSI C37.32 & IEEE C37.34 Rated continuous current Rated maximum voltage Rated short circuit-time current (momentary) Rated mechanical operations Rated interruption capability Rated ice breaking Rated Insulation level

Switches

Mounting arrangements

Horizontal upright Single side Double side Center side Double side V Vertical Underhung or inverted Underground

Grounding Switch

For grounding live parts at the station For grounding lines Single pole or gang operated

Switches

Switches

Switches

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

Station Power, Batteries Chargers

AC Power Two sources, emergency generator with transfer switch

Transformer cooling system Transformer load tap changer Transformer cabinet heaters Circuit breakers stored energy mechanism Circuit breakers cabinet heaters Building & Outdoor yard lights Battery chargers & outlets Building mechanical system Building A/C

DC Service Two battery banks Two DC distribution panel One circuit per breaker from each panel ( combine) For relay panel, one circuit from each panel Two circuit per transformer Use IEEE Std 485 for sizing lead acid batteries

Batteries

Type of batteries Vented Lead-calcium flooded cell Lead-selenium flooded cell Nickel-Cadmium flooded cell Valve Regulated Sealed

Design Practices

Design a room exclusively for batteries Design a room for two batteries Design battery room with a system to minimize hydrogen build up Provides acid spills containment Provide plastic shields over energize parts Provides safety equipment Consider hydrogen sensors Consider microprocessor controlled chargers

Cables

High voltage cables Client/PREPA regulations & buy cables from approved manufacturers Shielded cable

TR-Cross-linked Polyethylene EPR Ethylene Propylene Rubber

Low voltage Cables (600V)

Copper cable is more reliable Multiconductor, color coded cable is preferred Practice is: PT circuits #12 AWG CU CT circuits #10 or # 8 AWG CU Control Circuits # 14 AWG CU SCADA alarms #18 AWG CU

Substation Automation & Control

Deployment of substation and feeder

• perating functions and applications to

enhance operations and maintenance efficiencies with minimal human intervention.

SA Architecture

Basic Layer Architecture Process Level ( HV Equipment) Bay Level (Protection & Control) Station level HMI Architecture-1.pdf

Communication Protocols

IEC 61850

Communication Networks & Systems in Substation

Scada Real-time Self description Information models Configuration language IEC-61850-AP.pdf

Distributed Network Protocol DNP3 Communication Protocol IED devices

SCADA

alc-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

Protection

Zones of protection Generators Transformers Buses Transmission Lines Distribution Lines Zones of protection Primary Secondary Back-up Transformer Protection Differential Overcurrent Overexcitation Sudden pressure Gas detection Bus Protection Differential Overcurrent Breaker failure

Protection

Line Protection Non-directional overcurrent Directional overcurrent Impedance Power line carrier & pilot wire Distance & directional overcurrent Current differential (fiber optic channel) Phase comparison

Grounding Study

Grounding Grid General.pdf Combine-grounding-2.pdf

Line

Feed

Underground Feed

Underground Feed

MuseoCar\9569-combine-car.pdf

Control &Protection

Panel

Control & Protection Panel

Visit to the Site

Observe all site advantages and constraints Site restrictions (urban regulations) Check for future expansion constraints How lines and load circuits will be brought to the site and exit out Access to the site (how to move heavy equipment)

Equipment Layout

General System Layout Diseño Sub-w\VIEQ Subst Profile 1.pdf

GIS-PDF\GIS-Estudio\GIS-layout017.pdf

Post Visit to Site

Update project scope & get approval if required Update estimate if required Submit amended permits if required Adjust any design criteria if required Issue instructions for long lead equipment and site studies

Equipment Lead Time

Substation Transformers 10 -16 months Circuit Breakers 4 – 8 months High Voltage Switches 4 – 8 months Control & Protection Panel 4 – 8 months High Voltage GIS Equipment 8 – 12 months Medium Voltage GIS 8 – 10 months

Developed Project Time Table

Expected Service Date Permits Equipment Procurement (transformers, breakers, etc. lead time) Power supplier requirements (PREPA and others) Client operations input Get the approval: SLD drawing Site Layout Detailed design Construction Commissioning and as-built

Substation Layout

Substation Layout

Single 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 equipment Compliance with project’s scope and requirements Number of lines and load circuits All equipment fit within substation lot and complies with standards

Substation Layout

Finalize design requirements Outdoor High, low profile or GIS mixed Indoor GIS or GIS mixed System protection and power company requirements Overhead lines & load circuits; clearances Underground lines & load circuits Cables, Gas Insulated Lines, Bus (GIL, GIB)

Substation Layout

General Layout

GIS-PDF\General-Layout-GIS.pdf

Questions?

Thank You

Substation Design

General Concepts / Electric Equipment

Doeg Rodríguez ATRB, Ingenieros, CSP 787-236-6900 Angel T. Rodríguez Barroso MEC Engineering 605 Condado Avenue San Juan, P.R. 787-977-5045, angel.rodriguez@mecengpr.com

Transformers

Some of the Standards

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

References

ANSI C37 series – Protection and Control Equipment ANSI C57 Series – Transformers IEEE Standard 80- Substation Grounding NEMA Standards – Electric Equipment Construction National Electrical Safety Code Electric Power Substations Engineering 2nd Edition PREPA – Manuals and Standards Electric Power distribution Engineering 2nd Edition RUS Bulletin 1724E-300 IEEE/ANSI Standards