iosr-JEEE   Volume-2 ~ Issue-2

Abstract: Energy losses occur in the process of supplying electricity to consumers due to technical & commercial losses. The technical losses are due to energy dissipated in the conductors and equipment used for transmission, transformation, sub-transmission and distribution of power. These technical losses are inherent in a system and can be reduced to an optimum level. The system load factor of the Karnataka State Electricity Board (KEB) during 2009-10 was 70%, which is considerably low; It is worthwhile to make a study of the effect of system load factor on transmission & distribution loss reduction & the consequent increase in profitability of power utilities, with a focus on the Karnataka system. The study shows how the annual savings can be achieved through improvement of load factor.
Keywords: T & D losses, Load factor, Annual Savings, Reduction in T & D Loss, Load Factor on profitability

[1] KEB, Annual Administration Report 2009-2012 of Karnataka state Electricity Board, Bangalore, India.
[2] SRPC, Annual Report 2009-2012 of Southern Region Power Committee, Bangalore, India. (under CEA). www.srpc.kar.nic.in.
[3] SIEMENS (1981) Electricity Engineering Handbook, New Delhi, India: New Age International Private Limited.
[4] Economic Survey of Karnataka state, 2009-2012.

Abstract: This article briefly discuses the types and effects of hearing loss and then focuses on the topic of cochlear implants. The history of such devices is reviewed, as are their components and functions. Selection criteria for adult and pediatric implant candidates are outlined, and the procedures, risks, follow up, and likely outcomes of surgery are examined. The controversial issue of providing implants to children also addressed.

[1] Christie J. Helen Keller. In: Van Cleve JV, editor. Gallaudet encyclopedia of deaf people and deafness. New York: McGraw Hill; 1987:123-6.
[2] Schwab WA. Effects of hearing loss on education. In: Jaffee BE, editor. Hearing loss in children: a comprehensive text. Baltimore: University Park Press; 1977;650-4.
[3] Allen TE. Patterns of academic achievement among hearing impaired students: 1974 and 1983. In: Schildroth AN, Karchmer MA, editors. Deaf children in America. San Diego (CA): College Hill Press; 1986:161-206.
[4] Harris JP, Anderson JP, Novak R.An outcome study of cochlear implants in deaf patients.Audio logic, economic, and quality-of-life changes. Arch Otolaryngology Head Neck Surge 1995;121:398-404.
[5] Klein L, Huerta LE, National Library of Medicine (US). Early identification of hearing impairment in infants and young
[6] children. Bethesda (MD): US Dept, of Health and Human Services, National Institutes of Health; 1992:1-2.
[7] Ramsdell DA. The psychology of the hard of hearing and deafened adult. In: Davis H, silverman SR, editors. Hearing and deafness. New York:Holt, Rinehart and Winston; 1960:459-76.
[8] Luxford WM, Brackman DE. The history of cochlear implants. In: Gray RF, editor. Cochlear implants. San Diego (CA): College-Hill Press; 1985.
[9] The CTI bionic ear system. Sylmar (CA): Advanced Bionics Corporation; 2001:2.
[10] Balkany T, Gantz BJ, Steenerson RL, Cohen NL. Systematic approach to electrode insertion in the ossified cochlea. Otolaryngol Head Neck Surg 1996;114:4-11.

Abstract: Generally, the Power systems are subjected to a wide range of disturbances, small and large. For small disturbances, load frequency and excitation voltage control problems are non interactive. In the large interconnected power system, it is also desirable to maintain the tie- line power flow at a given level irrespective of load changes in any area. Therefore there is a need to go for automatic controlling equipment (called Automatic Generation Control) which regulates the changes in frequency and the tie line power so as to meet the changing demands. The AGC system solely cannot control the disturbances, it need another controller like proportional integral (PI), proportional integral derivative (PID) controller. PI controller is simple for implementation but takes more time and gives large frequency deviations. Large disturbance is concerned with the ability of the power system to maintain synchronism when subjected to a severe disturbance, such as a short circuit on a transmission line. In general rotor angle stability is taken transient stability of power system, which is the function of operating condition and disturbances. In order to improve the Transient Stability margin, FACTS devices has been implemented. In this paper, the transient stability improvement is verified using Simulink, with different FACTS devices, namely Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM). It has been observed that the FACTS devices, when placed slightly off-centre towards sending-end, gives better performance in improving transient stability and the location depends on the amount of local/through load. The results are experimented and simulated on MATLAB/Simulink environment.
Keywords: AGC, Conventional controller, Inter area power system, FACTS devices, SVC, STATCOM

[1] D. Murali, Dr.M. Rajaram, N. Reka "Comparison of FACTS Devices for Power System Stability Enhancement", International Journal of Computer Applications (0975–8887), Volume–No.4, October 2010.
[2] A. Calvaer, "Voltage stability and voltage collapse," CIGRE report, Paper 38.02, 1985.
[3] A. M. Chebbo, M. R. Irving, and M. J. H. Sterling, "Reactive power dispatch incorporating voltage stability" IEE Proc., vol.139, no.3, May1992, pp.253-260.
[4] Tan, Y.L., "Analysis of line compensation by shunt connected FACTS controllers: a comparison between SVC and STATCOM", Power Engineering Review, IEEE, Vol: 19, Issue: 8, Aug.1999, pp: 57-58.
[5] K.R. Padiyar, "Power System Dynamics – Stability and Control", 2nd edition, B.S. Publications, 2002.
[6] Narain G. Hingorani and Laszlo Gyugyi, "Understanding FACTS: Concepts and Technology of Flexible AC Transmission Systems", Standard publishers distributors, IEEE Press, 2001.
[7] K.R. Padiyar, "FACTS controllers in Power Transmission and Distribution", New Age International Publishers, 2008.
[8] G. W. Stagg, and A. H. El-Abiad, Computer Methods in Power System Analysis, McGraw-Hill, 1968.
[9] A. J. Wood, B. F. Woolenberg, Power Generation Operation and Control, John Wiley and Sons, 1984.
[10] D.P Kothari and I.J Nagrath " Modern Power System Analysis" 3rd edition Tata McGraw-Hill co, 2003.