EE25401 Transmission and Distribution – Semester IV – EEE – R-2025

Subject Code & Name: EE25401 – Transmission and Distribution

Regulation: R-2025

Semester: IV (Fourth Semester)

Branch: B.E. Electrical and Electronics Engineering (EEE)

Credits / L-T-P: 3 Credits | L-T-P: 3-0-0

Course Objectives

• This course introduces fundamental concepts and analysis of electrical power transmission and distribution systems.
• It covers modeling of transmission lines for AC and DC, including calculation of inductance and capacitance for various conductor configurations.
• Sag and tension calculations under different environmental conditions are discussed in detail.
• The course also examines types overhead line insulators used for different voltage levels, potential distribution, corona effects with mitigation techniques and underground cables.
• Overall, this course equips students with essential analytical skills for reliable power delivery.

Full Unit-wise Syllabus

Unit I – Modeling of Transmission Lines

AC and DC transmission systems, Resistance, Inductance and Capacitance Calculations, Single phase transmission lines, two wire system and composite conductors, Three phase transmission lines with unsymmetrical spacing, transposition of conductors, double circuit line, Bundled conductors Skin effect, Proximity effect.

Unit II – Performance of Transmission Lines

Short, Medium and Long transmission lines with Nominal-T, π and rigorous methods, ABCD constants, Power Circle diagram, Ferranti effect, Compensators - Series and Shunt.

Unit III – Sag and Tension Calculations

Overview of mechanical design aspects, Line Supports, Types of poles and towers, Classification and selection criteria, Sag and Tension Calculations: Supports at equal heights, Supports at unequal heights, Effects of wind and ice loading on conductor weight, Use of sag templates and safety clearances.

Unit IV – Insulators and Concepts of Corona

Overhead line insulators, Types of Insulators, Methods of Improving String Efficiency. Corona – mitigation methods, Grounding

Unit V – Underground Cables

Underground cables - Construction and types - Single core and multi core cables -Capacitance, Insulation resistance, Electric stresses and Dielectric loss – Grading of Cables, Capacitance Grading and Inter-sheath Grading.

Unit VI – AC Distribution Systems

Voltage Drop Calculations in AC Distributors for the following cases: Power Factors referred to receiving end voltage and with respect to respective load voltages.

Tasks

• T1: Compare AC and DC transmission systems with advantages and disadvantages.
• T2: Derive inductance equations for:; Single-phase two-wire systems; Composite conductors; Three-phase lines
• T3: Derive and calculate ABCD constants for different line models.
• T4: Study different types of transmission line supports and towers.
• T5: Study thermal behavior and current carrying capacity of cables.

Course Outcomes (COs)

• CO1: Explain transmission line modeling and compute resistance, inductance and capacitance for various conductor configurations.
• CO2: Analyze performance of transmission lines using different models and evaluate parameters such as voltage regulation, efficiency and ABCD constants.
• CO3: Apply mechanical design concepts including sag and tension calculations, and analyze insulators and corona effects.
• CO4: Evaluate underground cables and AC distribution systems for efficient and reliable power delivery.

Assessment Pattern (Quick Note)

• Weightage: Continuous Assessment 40% | End Semester Examinations 60%
• Internal methodology: Assignments (20%), Solution to application-oriented problems using software (20%), Solving of GATE questions (20%), Internal Examinations (40%)

Source: Official Anna University – B.E. Electrical and Electronics Engineering R-2025 Syllabus
Last Updated: October 2026