Unit 1 Introduction to Electrical Substations Contents

• Definition and Purpose of Substations:  Overview of substations as critical nodes in power systems  Importance in India’s power infrastructure

Unit 2 Types of Substations

•  Classification based on function: Transmission
• Switching substation  Classification based on voltage level: EHV, HV, MV, LV  Indoor vs. outdoor substations

Unit 3 Essential Features of Substations

•  Key characteristics: Reliability
• scalability, and maintainability.  Basic requirements for substation location (site selection) and accessibility

Unit 4 Typical Layout of Substations

6 lecture hours

•  Overview of substation layout components: Switchyard
• control room, and auxiliary systems.  Introduction to single-line diagrams (SLDs) of 66 kV / 132 kV / 220 kV layout.  Examples of common layouts (e.g.
• single bus, double Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering Subject Code: DI04009011 Subject Name: Substation Engineering bus). 2
• Substation Equipment For all the equipment covered in this unit
• Indian Standards (IS) are for references only and the questions of Unit 2 pertaining to Indian Standards (IS) should be avoided in theory exams
• considering the scope of the syllabus of this subject” Contents: 1
• Transformers (Power Transformers: IS 2026 Part 1 to 4 and Interconnecting Transformers: IS 1180):  Requirement of inter-connecting & power transformers  Operational and Maintenance checks of transformer  Condition monitoring (Parameters – Sensor/Methods – Alarm Threshold) 2
• Isolators (with and without Earthing switch) (IS 9921: Parts 1 to 5)  Types and Voltage class: Horizontal and Vertical break / double / centre break
• Manual / motorized
• with/without earthing switch.  Pad-locking arrangement
• mechanical and electrical safety interlocking between isolator and earth swich. 3
• Busbars (IS 8084
• IS 5082):  Types: strain
• rigid type  Material: aluminium pipes
• AAC  Ratings: Rated voltage
• material (Copper
• Short time withstand current
• peak withstand current
• temperature rise limits etc.  Functions: Switching
• Power transfer /distribution within substation  Maintenance: Joint inspections
• corrosion checks. 4
• Auto-Reclosers (IS 7567):  Types: Single-phase
• three-phase.  Functions: Automatic fault clearing
• circuit restoration.  Contact checks
• reclosing mechanism inspection.  IoT-enabled fault logging
• remote configuration

Unit 5 Surge Arrestors (IS 3070 Parts 1–3)

16 lecture hours

•  Types: Expulsion type
• Thyrite type
• Metal oxide (MO) conforming IEC 60099-4
• Routine and periodic maintenance procedures Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering Subject Code: DI04009011 Subject Name: Substation Engineering

Unit 6 Insulator, strings, Clamps and Connectors, Spacers ((IS

• IS 10162/14763)  Insulator Types: Porcelain type (Disc
• long rod)
• Composite type
• Silicon Rubber
• Hollow bushing type
• Bus post insulators  Clamps & Connectors: Aluminium alloy casting type A6, bi-metallic liner/strip
• galvanised mild steel.  Non-magnetic spacers  Routine and periodic maintenance procedures

Unit 7 Power Line Carrier Communication (PLCC) (IS 9149, 4119, 1947, 11538)

•  Components of PLCC
• Wave trap  Working of PLCC and applications

Unit 8 Batteries and DC Systems

13 lecture hours

•  Introduction to Lead Acid and NiCD batteries  Trouble shooting chart for Lead Acid Batteries (Troubles – Symptoms/Cause – Remedies)  Maintenance Checks for Lead Acid Batteries  Battery Charger -Float and Boost charging 3
• Substation Practices
• Earthing Systems, and Compensation Equipment Contents: 1
• Routine Substation Operations:  Switching schemes for 765 KV, 400 KV, 220 KV and 132 KV substations  Power flow and voltage level monitoring  Documentation and reporting for operational logs  Preventive
• Predictive and Proactive maintenance 2
• Earthing Systems (IS 3043):  Purpose of earthing systems
• Step & Touch potential
• Transferred & Floating potential  Earthing systems in substation: Solidly grounded
• Resistive (NER)
• Grid & Rods
• Counterpoise  General recommendation of IS 3043:2018
• IS 5613 (Part 2, Section 1)
• CEA 2010 Regulation (Rule 42) for earthing systems in substations. 3
• Compensation Equipment:  Capacitor banks: Introduction
• OUCB – Optimum Utilization of Capacitor Bank
• Case studies 10 22 % Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering Subject Code: DI04009011 Subject Name: Substation Engineering for optimal capacitor bank operation
• Commercial benefits of OUCB 4
• Safety Standards and Regulations (IS 5216 Part 1 and 2):  General recommendations of IS 5216 Part 1  General recommendations of IS 5216 Part 2  Typical safety clearances based on voltage level (minimum and working safety clearances).  Basic safety practices: Personal protective equipment (PPE)
• lockout-tagout procedures 4
• Specialized Substations and Automation Basics Contents: 1
• Gas Insulated Substations (GIS) & Hybrid GIS Substations (HGIS:  Overview: Purpose
• use in urban/high-voltage areas
• compactness.  Components: Circuit breakers for GIS, Disconnector switches
• non-fault initiating earthing switches
• High speed earthing switches
• three position disconnect / Earthing switches
• View ports, CT, PT, Pressure relief devices
• Density monitors
• Gas pass-through type insulators
•  Routine check list of GIS, HGIS substations 2
• HVDC Substations:  Overview: Purpose for long-distance/renewable integration.  Components: Converters
• DC transformers.  Ratings: DC voltage (e.g.
• power capacity (MW).  Functions and Maintenance (Efficient power transmission
• grid stability
• Converter valve checks
• filter inspections)  Digital monitoring of converter performance. 3
• Substation Automation Basics:  Introduction