The Course deals with Power distribution system with variousalternatives - Selection, Specification & procurement of electrical equipments- Substation Design with or without Trench - Automation in Equipment control.
The subjects are detailed with reference to the following
· Overview of industry and their requirement of electricalsystems.
· Role, Importance, Responsibility of Electrical Engineer.
· Client requirements & collection of specific data forprojects.
· Use of International Standards, Design Basis, std.practices/procedure and specifications
· Understanding Basic Design requirement based on the type ofvarious plants.
· Intra-discipline co-ordination with civil, process, mechanical,piping, telecom HVAC etc…
· Cable System Design.
· Introduction to Heat Tracing systems and cathodic protection.
· Design system for Power distribution, Earthings, Lightning andlightning protection.
· Vendor drawing review and approval – typical transformer.
· Introduction to Inspection of Equipments. Inspection methodologydiscussed for getting right inspection done. Practical inspection casespresented
Engineering of various types of Projects -----
The Participants are introduced to various aspects ofEngineering of Electricals of projects, the role played by electrical engineerin user friendly design of projects from concept to commissioning
What information, from whom information has to come & towhom electrical information has to go is well coordinated in this module to geta project design with almost no hiccups at execution & commissioning stage.
Key Processes in Electrical Project Design -----
The Various processes like extended basic engineering,Procurement of Electrical Equipments, Substation Design, overall cable TrayLayout plot, Power/ Lighting/ Earthing layout of each section of plant aredetailed What
Key single line diagram -----
This document is the key document developed for each project.This has all the aspects which we have considered for smooth operation of theentire plant This is the starting point of the project -- final record of thedesign carried out -- basis of procurement – should main bus and emergency busbe separate OR common -- selection of feeding switch board based onequipment location in the plant – Lighting board location in the plant OR insubstation – up to what level of distribution voltage the key sld is developedsand why -- Lighting transformer purpose -- Dual feed – auto transfer –loads off – electrical responsibility -- Dual feed – transfer on load –momentary – how done – check synchronizing relay -- Forward synchronizing –reverse synchronizing -- Castel & electrical interlock – standard voltagefor motors – system –
User list - Load list -----
This is a list through which project/ process departmentcommunicates to other departments & clients the various equipments bothstatic & rotary, the specifications with respects to their operatingtemperature, pressure etc. As electrical engineer we are interested in absorbedpower, method of control of motor & which equipments have to be addressedwith respect to power fluctuations. All these are communicated through variousfields in the user list. This list forms basic for the control design &thus directly to procurement of other electrical equipments like HV/ PCC/ MCC/LCS etc. Each & every field is explained with respect to application inengineering.
ShortCircuit understanding -----
Within this module the system fault level depends on varioussources of generation of power inclusive of high inertia drives where motor generatespower after disconnection due to the inertia of driven equipment. How thevarious reactance dictate the different levels of short circuit for selectionequipments is dealt.
· Short circuit ---critical for theentire system.
· Why does Short circuit current,remains very high for initially few cycles and gradually decreases and finallygets into steady state mode.
· Three types of reactance----- Sub transient reactance X’’d /Transient reactance X’d / Synchronousreactance Xd--- how long the sub transient/ transient and steady state currentlasts
· What is the current and time theCB and the board are to with stand --- what is interrupting duty expected ---canthe withstanding capacity be lower than interrupting capacity etc
· What is the meaning of high , lowX/R ratio
· CB generally opens (faultclearing time) in 8 cycles.
· Role of motors in faultcontribution
Electrical Equipments -----
Understandingthe why of the specifications from construction point of view, safety &operational ease of various electrical equipments for a project. All the electricalequipments of the project are covered in detail during the course
Theequipments covered are
A.2 HTSWITCHBOARD
A.3 TRANSFORMER
A.4 LTSWITCHBOARD
A.5 CABLES
A.6 BUS-DUCT
A.7 MOTORS
A.8 LOCALCONTROL STATION
A.9 DISTRIBUTION BOARD
A.10 LIGHT FITTINGS
A.11 DG SET
A.12 TG SET
A.13 BATTERY CHARGER
A.14 CAPACITORS & ITSCONTROL PANEL
A.15 NEUTRAL GROUNDINGRESISTOR
A.16 VFD
A.17 UPS
A.18 HEAT TRACING
A.19 CATHODIC PROTECTION
A.20 CONTROL PANELS /STARTER PANELS
A.21 CONSTRUCTION POWER
A.22 INSTALLATION
HV Switchgear -----
§ The typical values of short circuit ratings / current ratingsfor Busbars / Standard voltage ratings of HV switchgear for Industrialpremises as per applicable standard – type of CB – what is SF6 – vacuumdielectric – Fuse contactor units – configurations alternatives – componentsthat make a HV switchgear – list of type and routine tests . The various compartmentsare discussed.
§ Withdrawable vacuum circuit-breaker panel
(withswitchgear truck withdrawn and partition removed)
1 Panel ventilation (forced ventilation)
2 Low-voltage compartment
3 Connecting cables to low-voltage lug connector
4 Withdrawable vacuum circuit-breaker
5 Truck
6 Wipers of withdrawable section
7 Cover (stainless steel) to cable connection compartment (toolrequired to open)
8 Ventilation flap
9 Busbars
10 Metal shutters (internal protection against solidforeign bodies and touch) made of stainless steel
11 4MB bushing-type current transformer
12 Bar connection
13 Make-proof earthing switch
· Interlocks
Interlocks to prevent:-
· “Plugging in” of a closedbreaker.
· “Plugging in" abreaker with earthing isolator closed.
· "Closing" of the earthing isolator with breaker"plugged in".
· Pulling out the auxiliary circuitplug with breaker in the service position.
· Pushing in the breaker to theservice position, with auxiliary circuit plug not in position
Interlocks to prevent:-
· “Plugging in” of a closed breaker.
· “Plugging in" a breaker with earthing isolator closed.
· "Closing" of the earthing isolator with breaker"plugged in".
· Pulling out the auxiliary circuit plug with breaker in theservice position.
· "Closing" of the earthing isolator with breaker"plugged in".
· Pushing in the breaker to the service position, with auxiliarycircuit plug not in position.
· Earthing switch closing with CB in connected/intermediateposition.
Doors of withdrawable units withinterlock systems to avoid :
· Opening of compartment door when withdrawable unit is in connected/intermediateposition.
· Racking of withdrawable unit when compartment door is open
Transformer -----
· Tank – construction -- Base -- Reinforced to preventdistortion.-- Base channel – with rollers and pulling eyes-why -- Radiators –Detachable with shut off valves, air vent ,drain ,lifting lugs. can be fixedfor less than 500 kva.
· Why nonmagnetic gland plate -- Head room for terminationinspection
· HV fault withstand time – 0.2” – why wrt sec fault discuss -- LT& HT withstand relation -- Talk about loading vs Fault level
· Why tap changers -- -- From which windings taken and why-- What is the meaning of +- Tap position
· What happens in terms of transformer operation wrt + or – tap --Why called OCTC & not NLTC
· OLTC located where and why
· What is trafo capacity loss due to regulation Purpose ofconservator -- Oil resistance air bag – physical trafo mounted protections-- accessories
Ø PCC and MCC -----
Low voltage switchgear is asystem of standard sections -- Vertical panels of uniform height.-Discuss applicability,advantage & disadvantage -- Main Bus Bar -- The hot spot temperature 95°C---??
Auxiliary Interposing relay or terminal compartment alternatives ???? -- Sizedfor receiving specified number of cables -- three positions for the draw outtrolley --Switchgear Components
Power cum Motor Control Center --what is PCC ????, MCC -- Can we equate this to high voltage board --what arepanel sections --what is draw out etc. who prefers and why -- Control trafomodule Minimum 2000 VA control transformer -- CB modules /SFU modules / Auxterminal module
Switches / Fuses/Contactors/Thermal Overload Relay What is then diff betweenPMCC and MCC
Ø Cables ----
Why do we need cable? Typesof cables -- what you mean by 3.3/6.6 kV : 6.6/6.6 kV :6.6/11 kV: 11/11 kV – where are screens used -- core configurations– construction of HV and LV cable -- conductor types – temp withstand ofinsulations – laying conditions – derating factors applicable – bending radius-- points to be considered when selecting cables -- LV cable and hvcable main criteria
Ø Bus Duct -----
What is Busduct – HV – LV – phase segregated -- expansion jointsat suitable intervals – wall frame assembly – different adopter chambers – carein specs for no problem installation – why phase cross over chambers
Ø Motors -----
§ Motor application for various duties, different motor partsparticularly terminal boxes, Alignment facilities to be specified work horse –why DOL preferred – no of starts per hour and why – bidirectional vs.unidirectional –problems if wrong direction specified – turn down tank forlubrication -- Motor class F with permissible rise as per class B -- where are terminal boxes located -- phase segregated terminalboxes -- fans – lifting hook – temp detectors – polarisation index –howterminal boxes in HT can be rotatable like LT motors
§ Local Control Station -----
§ Why local control station. How many types-what use “NO” contactof STOP Actuator – ambient temperature effect. Why specify additional cableentry. Why 2 additional terminals— effect of extreme temperatures on MOC ofLCS
§ Lighting DB: -----
§ Configuration available should there be a lighting transformer-what is criteria for max Lighting transformer capacity- can’t we designlighting system without lighting transformer Limiting size of fuse in feeder
Ø Lighting -----
A good lighting is an aid toproductivity & comfort feeling. The lighting system like functionallighting for plant, overall lighting for safety, escape route lighting, workstation lighting without glare are addressed. Main point emphasized aestheticswith ease of maintenance, fault finding & isolation of defective lights inminimal time, retaining balance light for operation-coordinating with Civil,Architectural, HVAC group for lighting system & Supports for “no clash”.Developing standard installation drawings. Point by Point and coefficientmethod of lighting design is discussed
Ø Diesel Generator Set ----- |
Why DG sets- if required what capacity- input from where – when VD is high how solve – starting sequences - layout considerations |
POWER GENERATION SYSTEMS -- Prime Mover/Generator --Generator & AVR -- Generator Excitation Control Systems -- GeneratorProtection -- Generator Synchronisation – main task of AVR – how to read droopcharacteristics and analyse generator operation – synchro methods -- jacking oil
Ø Battery and chargers -----
Battery classification-Types- applications – duties – types –vented vs valve regulated – allowed Hydrogen concentration -- Battery Roomventilation requirements – sizing fundamentals – typical load profile – Chargerrequirements
Ø Power factor Correction -----
Sizing Capacitor Banks:
· Calculate total kW demand and power factor on eachswitchboard-(Refer to the load list for each switchboard)
· Determine the value of the power factor to be improved (powerfactor shall generally be higher than 0.9 lag and below unity )
Ø Packages -----
· Why package specs – how to prepare them for no hiccup execution– should it be a diluted version – format for package scope – minutes ofmeeting etc
Ø Uninterruptable Power Supply (UPS) -----
What is UPS- where used- alternatives-abnormalities in Grid- UPSConfigurations – Battery Sizing
Ø Variable Speed drive ----- |
What Is a Variable Frequency Drive? How Does aVFD Work Types of Drives - DC & AC -- ‘Types of AC Drives’ -- ‘SystemComponents of A.C. Drives’ -- Effects Of Drives On Electrical SystemApplication –benefits of VFD – how much savings -- magnetic amplifierapplication
The DOL Scheme for HV developed from components specified,developing block components for a scheme, LV scheme, Interconnection drg for atypical scheme
Ø Earthing -----
Ø Purpose ofearthing -- classification of earthing --concept of earthing --applicable standards -- quantities of good earthing --factors affecting theearthing resistance -- different types of earthing electrode -- calculatingresistance of baried earthing strip -- inputs required for earthing calculation-- . calculation of no. of earthing electrode factors effect on groundresistance
Ø Hazardous area Classification -----
Ø What isarea classification -- why has this to be identifies -- methods ofclassification -- How to avoid explosion – use of fire tringle inpractical situations- types of hazardous area equipment & applications –auto ignition temperature -- MEAG & max flame path- certificationunderstand -- IIC and IIA/B area and equipments differences – Dust Hazard
Ø Substation -----
Ø Nervecentre of power – what is it – reliability – as per of substation design –Receive – Distribute – Protect – Meter – Monitor – Cont –Segregation --Installation ease -- Ease of maintenance -- Handle emergencies -- Futureexpansion -- Replace any equipment in future – who are involved – what eruptsto be accommodated -- space allotment for others - clearances – columnspacing your priority
Ø Power Lighting Earthing layouts -----
Ø How toprepare – how to coordinate – generate weld able surface on concrete –construction friendly design for short execution time – Various methods ofcable engineering
Ø Lightfitting installation standards
Ø lightningprotection – coordinate with Civil for conductor fixing on sheets ofwarehouse
Ø Earth pitsand interconnections – Earth bus – Earthing conductor
Protection -----
Protective relays general – Introduction / operation principle /terminology of protective relaly / types of relays / instantaneousovercurrent relay / definite time over current relay inverse time overcurrentrelay / directional over currentrelay
Motor protectionrequirements - abnormal motor operating conditions. …..Prolonged starting /locked rotor condition -- Failure of / inadequate ventilation --Bearingfailure -- overloads -- Frequent starting / jogging - Singlephasing -- Inverted phase sequence -- Under voltages / Overvoltages -- Under frequencies / over frequencies -- Surge voltages-- Internal faults within the motor -- Earth faults
Ø Calculations -----
Transformer Sizing -- Cable Sizing -- Lightning Protection -- EarthingDesign Board Sizing -- Lighting Design --DG Sizing – Approach to battery sizing
Ø Cathodic Protection & Heat tracing -----
· Cathodic protection
· . Stray direct current corrosion
· 2. Bi-metallic corrosion
· 3. Galvanic corrosion of a single metal
· 4. Cathodic protection
· 5. Methods of applications
· 6. Selection of CP
· Heat Tracing
· . Types of heat tracing system
· 2. Overview of heat tracing system
· 3. Selection and sizing of appropiate heat tracer
· 4. Codes, approvals and standard
Ø Document list -----
Ø Detailsall the documents generated by electricals – its input source - outputsent to whom & why – specification list – calculations list – variousschedules – standard drawings – P/L/E layouts – inter conn schedule are alladdressed
Ø Tutorials – assignments – unit test- final exam ----
During the training the students are given assignments &tutorial work. These are followed by Weekly Assessments & final exam.The number of assignments will be at discretion of the faculty based onparticipants. The duration of Weekly Assessment & final exam are 2 & 3hours respectively. These will be increased suitably based on participant’senthusiasm, interest. These tests are designed to increase confidence of theparticipants by exposing them to variety of questions.
Data sheets ----
The data sheets form integral part of any equipment – Typical HV board, Transformer and MCC discussed |
Site Visit will be arranged at industrial plant either in shutdown or not working conditions.
Ø Cathodic Protection & Heat tracing -----
· Cathodic protection
1. Stray direct current corrosion
2. Bi-metallic corrosion
3. Galvanic corrosion of a single metal
4. Cathodic protection
5. Methods of applications
6. Selection of CP
· Heat Tracing
1. Types of heat tracing system
2. Overview of heat tracing system
3. Selection and sizing of appropiate heat tracer
4. Codes, approvals and standard
Ø Document list -----
Details all the documents generated by electricals – its input source - output sent to whom & why – specification list – calculations list – various schedules – standard drawings – P/L/E layouts – inter conn schedule are all addressed
Ø Tutorials – assignments – unit test- final exam ----
During the training the students are given assignments & tutorial work. These are followed by Weekly Assessments & final exam. The number of assignments will be at discretion of the faculty based on participants. The duration of Weekly Assessment & final exam are 2 & 3 hours respectively. These will be increased suitably based on participant’s enthusiasm, interest. These tests are designed to increase confidence of the participants by exposing them to variety of questions.
Ø Data sheets ----
The data sheets form integral part of any equipment – Typical HV board, Transformer and MCC discussed
Site Visit will be arranged at industrial plant either in shut down or not working conditions. |