January 6, 2012

POWER SYSTEMS-2 JNTU previous years question papers


POWER SYSTEMS-2 JNTU previous years question papers

Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks

1. (a) Derive an expression for the inductance per phase for a 3-phase overhead transmission line when conductors are unsymmetrical placed but lines are untransposed.
(b) Calculate the inductance and reactance of each phase of a three-phase 50Hz overhead high-tension line (HTL) which has conductors of 2.5cm diameter. The distance between the three-phases are [8+8]
i. 5m between A and B,
ii. 4m between B and C and
iii. 3m between C and A . Assume that the phase conductors are transposed regularly.

2. (a) What is a nominal circuit? Find ABCD constants of nominal-T and nominal circuits of a transmission line.
(b) A balanced 3-phase load of 35 MW is supplied at 110 kV, 50Hz and 0.8 p.f lag by means of a transmission line. The series impedance of a single conductor is (15+j35) ohms and the total phase-neutral admittance is 300 × 10-6 mhos.Use nominal - T method to determine
i. A, B, C, D constants of the line,
ii. Vs
iii. regulation of the line and
iv. efficiency.

3. (a) Derive the equivalent ABCD constants of a transmission line connected in series with an impedances at both ends.
(b) The per-unit-length parameters of a 215kV, 400km, 60Hz, three phase long transmission line are y = j3.2 × 10-6 mhos per km per phase and z = (0.1 + j 0.5) ohm/km. The line supplies a 150 MW load at unity power factor. Determine
i. the voltage regulation
ii. the sending-end power and
iii. the efficiency of transmission. [8+8]

4. (a) What is the outcome of the transient in the transmission lines? Develop the differential equation for the transient in the transmission system.
(b) A 500 kV, 2 µsec, duration rectangular surge passes through a line having surge impedance of 350  and approaches a station at which the concentrated earth capacitance is 3×103 pF. Calculate the maximum value of surge transmitted to the second line. [8+8]

5. (a) What is corona? What are its effects and how are they reduced?
(b) Find the disruptive critical voltage and visual voltage of a 3-phase transmission line operating at 132 kV, the conductors being 1.5 cm in diameter and arranged in delta with spacing of 4 m. The surrounding air is at a temperature of 320C and barometric pressure 74 cm of mercury. The various factors are irregularity factor = 0.85, surface factor for local corona = 0.7, surface factor for decided corona = 0.80, Breakdown strength of air = 21.21 kV/cm, assume fair weather condition. [8+8]

6. (a) Explain why suspension type of insulators are preferred for high voltage overhead lines. Sketch a sectional view of one unit of the suspension type insulator and describe the construction.
(b) An insulator string containing five units has equal voltage across each unit by using disc of different capacitances. If the top unit has a capacitance of C and pin to tower capacitance of all units is 20 percent of the mutual capacitance of top unit. Calculate mutual capacitance of each disc in a string. [8+8]

7. (a) Explain the factors affecting the mechanical design.
(b) An over head line with stranded copper conductor is supported on two poles 200 meters apart having a difference in level of 10 m the conductor diameter is 2 cm and weighs 2.30 kg/m square meter of the projected area and the factor of safety is 4. The maximum tensile strength of the copper is 4220 kg/square meter. [6+10]

8. (a) Describe briefly some commonly used insulating materials for cables.
(b) A 12.5 kV single-core cable has an outside diameter of 8 cm. Determine the radius of the core and the electric field strength that must be withstand by the insulating material in the most economical (optimal-ratio) configuration

FEEL USEFUL PLEASE GIVE +1

0 comments :

Post a Comment

Get Syllabus in your Mail

Labels

Accenture Admission Notice - 2010 Admission Notification Anna University Anna University Chennai Anna University Question Papers Anna University Trichy Apparel Technology and Management Aptitude Questions Arts and Science Colleges Biomedical Engineering C and CPP Ebooks Calicut University CBSE Question papers Civil Engineering Civil Service Exams Colleges in India Colleges Result Computer Science Engineering Core Jobs CS R2008 CSE CSIR NET EBooks Download ECE EEE EIE Electives Electrical and Electronics Engineering Electronics and communication Electronics and Instrumentation Engineering Engineering Engineering Colleges in Maharashtra Engineering Colleges in TamilNadu Engineering Admissions Engineering Colleges Engineering Colleges in Karnataka Engineering Jobs Engineering Syllabus Entrance Exam Dates Entrance Exam Results Entrance Examination Exam Time Table Experiencer First Year Syllabus Freshers Full Time Jobs Government jobs in india Hardware and Networking Jobs Hotel Management and Catering Technology IGNOU Information Technology INTEVIEW QUESTIONS IT Jobs JNTU Question Papers Jobs in Bangalore Jobs in Chennai Jobs in Coimbatore Jobs in Delhi Jobs in Hyderabad Jobs in India Jobs in Kerala Jobs in Noida Jobs in Tamilnadu Jobs in TATA Karnataka Educations Lab Manuals Mechanical Engineering Medical Colleges Placement Papers Plus 2 Preparation for exams Private Jobs in India Question Papers Question Papers Download Results Announcement Semester 1 Semester 2 Semester 3 Semester 4 Semester 5 Semester 6 Semester 7 Semester 8 Syllabus Syllabus Download Tamil Movie TCS Placement Papers Teaching Jobs TECH MAHINDRA Textile Technology Top colleges University Results UPSC VICEVESVARAYA TECHNOLOGICAL UNIVERSITY waec Walk-in Interview Web Designers

Followers

Archive

Anna university Engineering Syllabus

Earn Money From Online

Government jobs in india

Admission Notification

Total Pageviews

 

Privacy Policy
http://topengineeringcollegesintamilnadu.blogspot.com use third-party advertising companies to serve ads when you visit our website. These companies may use information (not including your name, address, email address, or telephone number) about your visits to this and other websites in order to provide advertisements about goods and services of interest to you. If you would like more information about this practice and to know your choices about not having this information used by these companies, click here.