Course Title: 
Design of Electrical Systems
Course Code: 
Year Taught: 
Undergraduate (UG)
School of Engineering

'Design of Electrical Systems' is a course offered in Electrical and Electronics Engineering program at School of Engineering, Amrita Vishwa Vidyapeetham

Unit 1

General Introduction, Gathering specific data, Adoption of design - parameters for the particular project, Selection of basic design philosophies, Detailing the electrical System, Preparation of as - erected drawings and design - manuals.

Maximum-demand – MD estimation, Demand factors for HV motors, Calculation of MD on the MCCs, MD, estimation for an entire load-centre substation and MSS, Statutory Inspector's approach to MD estimation.

Unit 2

Sizing of transformer capacity on basis of MD calculations, Consideration and constraints in the sizing of transformers CB ratings, Split bus arrangements, sizing of power-transformer capacity, Sizing of distribution transformer, capacity at ICSS, Techno-economic studies on selection of transformer sizes, sizing the transformer to meet HV motor, starts and voltage dips.

Short-circuit calculations, SC analysis, standards for the SC analysis, Passive and dynamic reactance to be considered for SC analysis, Reactance multipliers for first cycle diagram for SC analysis of 415V system, The computation of AC components of fault currents, Determination of DC component of the fault current and the total fault current, IEC equations, The impact of CB status on fault levels.

Unit 3

Selection of cable sizes, Continuous rating of cables (Standard rating and netrating), Thermal ampacity of cables, Short time short circuit rating of cables, Mechanical withstand of short circuit forces, Techno economic consideration in selection of cables, SC-withstand capacity of 1.1 kV cable, Voltage drops in 415V motor, feeders and voltage drop based ampacity, The use of copper cables for motors of rating less than 7.5 kW.

  • N.Balasubramanian ‘Design of Electrical Systems (For Large projects)’, Revised edition, The Rukmini studies, Chennai, 1999.
  • TNEB Hand book
  • IEEE Hand book