TRANSMISSION AND DISTRIBUTION OF ELECTRIC POWER # 1) BASIC OF TRANSMISSIONS 1.
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State the necessity of transmission of electricity State the classification of different transmission system on the basis of voltage levels State the comparison between primary transmission and secondary transmission system State the standard transmission voltage in INDIA Why transmission of electric power is necessary? Classify transmission line onbasis of voltage Why electric power is to be transmitted at high voltages? Draw single line diagram of AC supply system Compare underground transmission system with over‐head transmission system Compare cable conductor with the over‐head lines Give the voltage levels of generation, primary and secondary transmission and secondary distribution 12. Draw a Block Diagram of POWER SYSTEM. #2) TRANSMISSION LINE COMPONENTS 1.
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State the different transmission line components in the system State the comparison between solid stranded and bundled conduction Draw a neat sketch of pin insulator. State the causes of failure with its limitations Each line of 3‐phase system is suspended by a string of 3 similar insulators, if the voltage across the line unit is 17.5 kV. Calculate the line to neutral voltage. Assume that the shunt capacitance between each insulator and earth is 1/8th of the capacitance of the insulator itself. Also calculate the string efficiency. Each line if 3‐phase system is suspended by a string of 3 similar insulators. If the voltage across the line unit is 18kV, Calculate the line to neutral voltage. The shunt capacitance between each insulator and earth is 1/9th of the capacitance of the insulators itself. Find the string efficiency. Draw a neat diagram, showing the various parts of high voltage single core cable. Give the classification of cable according to voltage for which they are manufactured With the help of diagram draw‐in‐system for laying of underground system. State its any 2 Advantages. List any 4 components used in transmission line. What are ACSR conductors? State is advantages? Explain Suspension type insulator and Write its any 4 advantages. A 3ph transmission line is being supported by 3 disc insulator. The potential across top and middle unit are 8kV and 11kV. Calculate i) Ratio of capacitance between pin and earth to self capacitance of each unit ii)String efficiency. Compare suitability of copper and aluminium as conductor material for transmission line What are the various part of conductor high voltage cable.Explain with diagram Explain any one method for laying of underground cables with neat sketch 15.
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Name the Important components of an overhead transmission lines State advantage of bundled conductor State 4 factors which affects the life of line insulators Define ‘sag’ related to transmission line.State factors on which it depends Enlist the various types of supports used for installing a transmission line.State their applications as voltage level of transmission and span of line In a 33kV overhead line there are 3 units in the string of insulators.If the capacitance between each insulators pin and earth is 11% of self capacitance of each insulators.Determine i)The distribution of voltages over 3 insulators.Ii)String efficiency State desirable properties of cable Explain different methods to improve string efficiency Describe some commonly used insulating material for cable Write any 4 advantages disc insulator,also give the formula for safety factor of insulator and give its value of pin type insulator A string of 3 unit suspension insulator observed to have voltage distribution on top disc 9kV, middle disc 12kV, Find i) Ratio of shunt to self ‐capacitance ii)bottom most disc voltage iii) string efficiency Write any four required characteristics of line support Draw a neat sketch of double circuit steel power with all the component shown If the maximum permissible tension in the line of spans 200m is 1450kg. The weight of the line is 0.864 kg/m . Calculate the sag. For wooden pole has supporting structure i)Name the wood used and name the preservative used for this pole ii)Any two advantages iii) Any 2 disadvantages iv)Area of application Name the type of conductors with their Brand/Trade name. State the concept of string efficiency Explain the term: i)Metallic sheathing ii)Mechanical protection Draw a neat sketch of double circuit RCC pole Define:safety factor of insulator.Give the value for it for pin type insulator Write down any 4 properties of line support Write any 4 properties of conductor State different factors on which spacing between conductor depends #3) TRANSMISSION LINESPARAMETERS 1. Explain the effect of R,L, and C 1 ph Transmission lines? 2. Discuss the effect of p.f. of load on efficiency for regulation of transmission line. 3. Define:‐ 1. Transmission Efficiency 2. Voltage Regulation in transmission line. 4. Explain effect of poor power factor on efficiency and voltage regulation of transmission line? 5.
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Define voltage regulation of a transmission line. State the regulation of transmission line. State its percentage formula. Explain: Skin Effect. What is Skin Effect ? On which factors does skin effect depend? State skin effect of transmission line where these effect occurs? Define:‐ Skin Effect in A.C.Transmission line? In AC transmission lines, more current passes through the outer surface of the conductor state with reasons if the above statement is true or false? State proximity effect of transmission line where these effect occurs. Explain proximity effect in power system? State Ferranti effect of transmission line where these effect occurs. Explain Ferranti effect with help of phasor diagram? Draw phasor diagram of a 11kv, 20km line having lending power factor load. With the help of neat diagram explain the concept of transposition of conductor? Explain why transposition of lines are done? Explain phenomenon of Corona? State factor affecting and advantages of corona? Discuss the methods of reducing corona effect. #4.Performance of Transmission lines:‐ 1.
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Classification of transmission lines based on length and operating voltage? Define medium voltage transmission? And give length and operating voltage of line? Draw phasor diagram of short transmission lines for unity power factor condition? Derive equation for voltage regulation of short transmission lines? Derive equation for the short transmission line with and without load for lagging power factor? How load factor affects the performance of transmission line? What are the effect of Lagging and leading p.f. of the load on regulation? In medium transmission line, for nominal T method show the derivation for sending end voltage with the help of neat phasor diagram? Draw nominal π network for medium transmission line. Draw its vector diagram? How the regulation and efficiency are determined for medium transmission line using End condenser method? Write down sending end voltage, sending end current by using generalized circuit constants of transmission line. Mention two important points about it. Draw equivalent circuit of short transmission line. What do you understand by medium transmission lines? How capacitance effects are taken into account in such lines? Draw nominal π network for medium transmission line. Draw its vector diagram and state its ABCD Constants? #5. Extra High Voltage Transmission 1. Discuss the advantages of Extra high Voltage Transmission? 2. Discuss the limitations of EHVAC wrt distribution system? 3. State the reasons for adoption of EHV system and 3 phaseA.C.System? 4. Draw the block diagram of HVDC transmission starting from generator? Also wirteadvantags and limitation of HVDC System? 5. Mention different types of HVDC Links? And explain any Two in detail? 6. Comparison between HVDC and EHV transmission system? 7. HVAC in Maharashtra State? #6. AC Distribution System 1. Draw the Single line diagram showing a typical arrangement of distribution system and define and explain the terms: Feeder, Distributor and Service Mains. 2. Explain the Radial system of distribution. State its Advantages? 3. Explain Ring Main system of distribution and state its advantages? 4. What parameters are to be considered while designing a feeder? 5. What do you mean by primary distribution system and secondary distribution system? 6. Explain two wire and Three wire D.C. Distribution System? #7. Primary and Secondary Distribution:‐ 1. Define substation. State different types of substation according to service requirements? 2. Classify Substation on basis of: Service requirements:‐ Constructional features:‐ 3. Draw typical layout of underground substation? 4. Draw single line diagram of a pole mounted substation. Name all the components and state their features? 5. State the comparison between Indoor and Outdoor Substation(Any 8 points)? 6. Describe the factors affect the location of site selection for substation? 7. State the functions of the following:‐ • Isolators • Lightning Arrestors • Busbar • Insulators • Circuit Breaker • Current Transformer • Potential Transformer • Relays. 8. Draw the key diagram of a typical 66/11kv substation showing all the equipment’s of a substation?