# Transmission and Distribution of Electrical Energy-1 Syllabus Diploma in Electrical Engineering, Regulation 2010, Short Suggestion, Exam Dates, Exam Routine, Question Out, Book list with code

To provide the students with an opportunity to acquire knowledge, skills and attitude in the area of transmission and distribution electrical energy with special emphasis on:

• Different types of transmission and distribution systems of electrical energy.
• Comparison of different types of transmission and distribution system.
• Electrical and mechanical design of overhead lines.
• Survey of transmission and distribution line route.
• Performance calculation of overhead transmission line.

# SHORT DESCRIPTION

Supply system: Different systems of transmission; Aspect of system loss; Mechanical design of overhead lines: support of overhead lines; conductors & conductor materials; Insulators; Effect of sag; Methods for survey of transmission/distribution line route; Voltage distribution of suspension insulator; Corona; Erection of poles and drawing of conductors of overhead line; Electrical design of overhead line: Resistance of the line conductor; Skin effect of transmission line; Effect of inductance on transmission line; Effect of capacitance of overhead transmission line; Performance of transmission lines: Voltage regulation and efficiency of short transmission line.

Theory:

# SUPPLY SYSTEM

• Understand different systems of transmission of electrical energy.
• Explain the transmission and distribution system of electrical energy.
• Categorize various systems of transmission and distribution of electrical energy.
• Define Feeder and Distributor.
• Compare betn feeder & Distributor.
• Compare between overhead and underground transmission and distribution system.
• Explain the advantages of high voltage transmission over low voltage transmission.
• Compare the cost of conductor of different overhead systems.
• Compare the cost of conductor of underground system with overhead system.
• Describe the process of choosing the working voltage for transmission and distribution system.
• Calculate the most economic working voltage for transmission of electrical energy.
• Express the equation for the most economic size of conductor by Kelvin’s law.
• Solve problems on Kelvin’s law.
• Describe the limitations to the application of Kelvin’s law.
• Understand different aspects of system loss.
• Explain the term system loss
• List the factors involved in system loss.
• Explain how system loss can be minimized.
• Discuss the most economic power factor.
• Express the equation for most economic power factor.
• Solve problems on most economic power factor.

# MECHANICAL DESIGN OF OVERHEAD LINES

• Understand the supports of overhead lines.
• List the main components of overhead lines.
• Categorize the line supports.
• Describe different types of line supports.
• Mention the characteristics of line supports.
• Describe the vibration dampers.
• Understand the conductors and conductor materials.
• List different types of line conductors used in overhead transmission and distribution lines.
• Mention at least five properties of conductor materials.
• Compare the properties of copper, aluminium and ACSR conductors.
• Understand the line insulators and their characteristics.
• List different types of insulators.
• List insulator materials.
• Describe the propertie of insulators materials.
• Describe the pin and suspension type insulators.
• Compare the advantages and disadvantages of pin and suspension type insulator.
• Mention the uses of different types of insulator.
• List the causes of failure of insulators.
• Explain different types of test of insulators.
• Understand sag and its effect.
• Explain the sag of transmission line.
• List the factors affecting the sag.
• Explain the spacing between conductors and span length.
• Express the deduction of the formula to calculate the sag of conductors between two poles of equal height.
• Express the deduction of the formula to calculate the sag of conductors between two poles of unequal heights considering effect of ice and wind pressure.
• Solve problems on sag of transmission line.
• Explain the effects of vibration on the transmission line and prevention of vibration.
• Describe the measure for the prevention of vibration.
• Understand the methods for survey of transmission / distribution line route.
• List the survey instruments required for survey of transmission / distribution line.
• Explain the uses, errors and accuracy of survey instruments.
• Describe the process of measuring the angles by compass, level and theodolite.
• Explain leveling, alignment, surveying and pegging of the route.
• Explain the methods of measuring vertical and horizontal heights.
• List the principle factors in routing overhead power lines.
• Understand the voltage distribution of suspension insulator.
• Explain string efficiency.
• Describe the methods of improving string efficiency.
• Solve problems on string efficiency.
• Express the deduction of equation for voltage distribution across each unit of a string of suspension insulators.
• Describe the methods of voltage grading in suspension insulators.
• Describe the method of equalization of voltage of suspension insulators by guard ring.
• Solve problems on voltage distribution and voltage grading.

• Understand the phenomenon of corona.
• Define corona of overhead transmission line.
• Discuss the effect of corona.
• Explain at least four factors that affect corona.
• Express the derivation of the relation for disruptive critical voltage, visual critical voltage and power loss due to corona.
• Discuss the methods for minimizing corona.
• Understand the erection of poles / towers and drawing of conductors of overhead line.
• Describe the procedure of erection of poles of overhead transmission / distribution line.
• Describe the procedure of erection of towers of overhead transmission line.
• Describe the procedure of fixing crossarm and insulator.
• Describe the drawing of conductors of overhead line.
• Describe the erection of stay / guy wire.

# ELECTRICAL DESIGN OF OVERHEAD LINE

• Understand the resistance of line conductor.
• Describe the line constant of transmission line.
• Express the deduction of the equation for calculating resistance of the line conductor.
• Solve problems on the resistance of the line conductor.
• Understand the skin effect of transmission line.
• Explain the skin effect of transmission line.
• Express the equation for calculating skin effect resistance.
• Explain the proximity effect.
• Understand the effect of inductance on transmission line.
• Explain the flux linkage of a conductor due to internal and external flux.
• Express the deduction of the equation for inductance of a single phase and three phase overhead transmission line in terms of Geometrical Mean Distance (GMD) and Geometrical Mean Radius (GMR).
• Solve problems on inductance of single phase and three phase lines.
• Describe the inductance of three-phase line with double circuit.
• Explain the transposition of line conductors.
• Understand the effect of capacitance of overhead transmission line.
• Explain the electric potential of a transmission line.
• Express the derivation of the equation to calculate the capacitance of single phase and three phase overhead transmission line.
• Solve problems on capacitance of single phase and three phase overhead transmission line.
• Explain the capacitance of double circuit three phase overhead line.
• Explain Ferranti effect.

# PERFORMANCE OF TRANSMISSION LINES

• Understand the voltage regulation and efficiency of short transmission line.
• Express the equation to calculate voltage regulation of overhead short transmission line.
• Express the equation to calculate efficiency of overhead short transmission line.
• Identify the effect of load power factor on voltage regulation and efficiency of overhead short transmission line.
• Draw vector diagram of short transmission line performance calculation.
• Solve problems on voltage regulation and efficiency of overhead short transmission line.

Practical:

• Survey and estimate the electrical loads of an area.
• Select the area / section of which the electrical loads are to be surveyed.
• Observe and record the load of each point of the area.
• Calculate the amperage of the area and the sub-area.
• Calculate the load of main circuit and sub-circuits.
• Draw the integrated load curve.
• Draw the actual load curve.
• Draw the ideal load curve.
• Perform the selection of economical voltage for generation, transmission and distribution of electrical power.
• Select generating voltage.
• Select voltage for transmission and distribution of electrical power.
• Select required type of insulators and poles.
• Prepare the layout diagram of an electrical project.
• Draw the layout of the selected electrical project.
• Draw the complete wiring diagram of the electrical project showing transmission line, distribution line and service mains.
• Indicate the power source.
• Perform the identification of different components of LT and HT over head lines.
• Identify the components of LT over head lines.
• Identify the components of HT over head line.
• Prepare a report.
• Perform the measurement of the horizontal distance between poles.
• Collect the instruments/ equipment commonly used in surveying.
• Measure the horizontal distance between poles over different ground conditions using tape and chain.
• Record the measurement of distance.
• Plot the line route showing the measurements.
• Perform the measurement of the angles and heights of poles / towers.
• Select the instruments for measuring angles and heights of poles.
• Measure horizontal angles.
• Measure vertical angles.
• Measure vertical heights of poles / towers.
• Survey and level the power lines.
• Visit an actual high voltage power line route covering a distance of approximately five span.
• Record ground levels, angle of route, interfering obstacles and length.
• Draw a ground profile of the line route, showing the support positions and ground clearance on river crossing and canal crossing.
• Perform the measurement of sag of a transmission / distribution line.
• Fix up the sag boards.
• Set the theodolite in proper position.
• Measure the sag of a transmission / distribution line using theodolite.
• Prepare a report.