• L&T-Sargent & Lundy
  • L&T-Sargent & Lundy

Transmission & Distribution

Capitalizing on its strength in core engineering services related to power projects, L&T-S&L has extended its service portfolio to include Transmission & Distribution Engineering Services for Utilities, IPPs and private power companies.

We offer T&D engineering services in the following areas:

  • Indoor/AIS/GIS Substations
  • Power Distribution System
  • Power System Studies

1. Substations / Power Distribution Systems

Basic & Detailed Engineering Indoor/AIS/GIS


  • Main Single line Diagram
  • Equipment Layout
  • Grounding, Shielding Protection & Lighting
  • Raceway design
  • Procurement Support
  • Vendor drawing Review
  • Cable Interconnection schedule

Protection and Automation Systems

  • Relay and Metering Diagram
  • Protection Logic Diagrams
  • Interlock /Inter trip Logic Diagrams
  • CT/VT Adequacy Check calculations
  • Preparation of SAS, SOE, TFR and DSM Point list
  • Relay Setting Calculations

Civil, Structural and Architectural

  • Site Development Plan
  • Civil and Structural Drawings
  • Architectural Drawings/Designs
  • Drainage and Plumbing
  • Vendor Drawing review


  • HVAC System
  • Capacity Calculation
  • Detail Ducting design
  • Air Flow & Control Schematic
  • Fire Fighting System
  • Calculation and design of Fire protection system
  • Piping design and network analysis
  • Hydrant and spray system piping layout

2. Power System Studies

Load flow calculations

For full determination of voltage, active, reactive power, power factor and transformer control requirements as well as the verification of equipment ratings in the event of outages and faults in a power system

Load Flow Calculations

Reactive power compensation study

To improve power factor of the power system by suitably placing capacitor banks or other type of reactive power compensation device.

Reactive Power Compensation Study

Short circuit calculations

Considering symmetrical and asymmetrical faults, for the verification of equipment rating, earthing requirement, fault voltages and current as well as equivalent connection point impedance.

Short Circuit Calculations

Transient Simulation Study (In IEEE Format)

Determination of critical fault clearing time under different loading and operating conditions

Transient Simulation Study

Motor Starting Study (Static / Dynamic / Reacceleration)

To check for severe disturbances to motor, other locally connected loads and also to buses, electrically remote from the point of motor starting. The possibility of motor reacceleration under different contingency conditions, is also checked

Protection Relay Coordination

Protection relay coordination calculation and settings for identification of the most suitable settings for protective relays for various fault conditions so as to provide protection coordination to the plant equipment with optimum sensitivity, stability and selectivity.

Protection Relay Coordination

Insulation Coordination Study

For selection of standard withstand voltages, which characterizes the insulation of equipment under study by checking the magnitudes of over voltages expected in the system due to different factors like lightning, switching, temporary overvoltage and very fast transients.

Insulation Coordination Study

Ferro Resonance Study

Ferro resonance study for checking the configurations leading to unusual high voltages in the system because of Ferro resonance.

Ferro Resonance Study

Arc Flash Study

Arc flash study to determine the flash protection boundary and the appropriate level of personal protective equipment during occurrence of electrical arc flash.

Software Deployed

Various advanced software are deployed to enable accuracy and efficiency in our deliverable.

  • ETAP - System Studies
  • AUTOGRID PRO - Grounding Studies
  • Micro station - Layouts & SLD's
  • PSCAD & EMTP - Insulation Coordination Studies, & Ferro-resonance Analysis
  • Dialux - Lighting Calculations
  • Staad Pro SAFE ETABS Framework Plus
  • Bently Architecture P-Arch


Download  Transmission & Distribution Services Brochure