iosr-JEEE   Volume-3 ~ Issue-3

Abstract: The STATCOM (Synchronous Static Compensator) based on voltage source converter (VSC) is used for voltage regulation in transmission and distribution system. The STATCOM can rapidly supply dynamic VARs required during system faults for voltage support. Strict requirements of STATCOM losses and total system loss penalty preclude the use of PWM (Pulse-Width Modulation) for VSC based STATCOM applications. This constraint of implementing VSC without PWM functionality, results in over-currents and trips of the STATCOM during and after system faults, when its VAR support functionality is most required. In this paper, we propose and develop an "emergency PWM" strategy to prevent over-currents (and trips) in the VSC during and after single line to ground system faults, LLLG faults and to ensure that the STATCOM supplies required reactive power. The Simulation results are shown for a 48-pulse VSC based ± 100 MVAR STATCOM connected to a 2- bus power strategy to prevent VSC over-currents and to supply required reactive power under line to ground system faults.
Keywords -STATCOM, Voltage Source Converter (VSC), Pulse-width Modulation (PWM), Single line to ground fault.

[I] N.G. Hingorani, "Power Electronics in Electric Utilities: Role Of Power Electronics In Future Power Systems," Proceedings ofthe IEEE, vol. 76, pp. 481, 1988.

[2] N.G. Hingorani and L.Gyugyi, "Understanding FACTS: concepts And Technology of Flexible AC Transmission Systems:IEEE press, 2000.

[3] L.Gyugyi, "Reactive Power Generation And Control ByThyristor Circuits," IEEE Trans. Ind. Appl., vol. la-15, no. 5, pp.521-532, Sept.ioct., 1979

[4] L.Gyugyi, "Dynamic Compensation of Ac Transmission Linesby Solid-State Synchronous Voltage Sources," IEEE, PES SummerPower Meeting, Paper No. 93 SM 434-1 PWRD, 1993.
[5] C.W. Edwards et aI., "Advanced Static Var GeneratorEmploying GTO Thyristors," IEEE, PES winter Power Meeting,Paper No. 38wml09-1, 1988.

[6] L.Gyugyi, "Dynamic Compensation of Ac Transmission Linesby Solid-State Synchronous Voltage Sources," IEEE, PES SummerPower Meeting, Paper No. 93 sm 434-1 pwrd, 1993

[7] C. Schauder et al. "TVA STATCON project: design,installation and Commissioning," CIGRE paper 14-106, 1996.

[8] E.Larsen et al. "Benefits of GTO-Based Compensation Systemsfor Electric Utility Applications," IEEE, PES summer powermeeting, Paper no. 91 sm 397-0 TWRD, 1991.

[9] J.B.Ekanayake and M.Jenkins, "A Three-Level AdvancedStatic Var Compensator," Power Delivery, IEEE Transactions on,vol. 11, pp. 540, 1996. [10] "Evaluation of Advanced Static Var Generators," EPRIReport No. EI- 3397 MAY 1984.

Abstract: Interest involves a careful design of 1.5KVA hybrid power supply for power reliability. A renewable single source system for a higher power demand application is often high in cost due to sizing of the source of supply component to meat reliability requirements. The system design is considered for the administrative office of the head of department, electrical and electronics engineering in Cross River University of technology, Calabar, Nigeria. The system operate at minimum running cost, population free environment, noiseless, reliable and provide the convenient of a twenty-four hour power supply. With this system, energy efficiency is achieved by lowering demand using dem
Keywords: Hybrid power supply, Power reliability, PV system, Inverter.

[1] Akpama, E.J.,"Designing a photovoltaic sustained sector: a review of current practice,"domestic use of energy conference, pp 155-160. 2011.

[2] M. Marvwan& H. ImadIbrik, "Techno- economic feasibility of energy supply of remotevillages as Palestine by PV- systems, diesel generators and electric grid," renewable andsustainable energy. Reviews pp 128-138, 2006.

[3] Sambo, A.S., International centre of energy, "Energy and Development Report, Renewable Electricity Action Program," federal ministry of power and steel, Nigeria 2006.

[4] Augustine C. &Nnabuchi M. N. "Relationship between Global Radiation And Sunshine Hours ForCalabar, Port Harcourt And Enugu, Nigeria." International Journal of physical sciences vol. 4(4), pp.182-188, 2009.

[5] Chimeka I. U, &chineke T. C. "Evaluating The Global Solar Energy Potential AtUturu, Nigeria."International journal of physical sciences.Vol.4(3), pp 115-119, 2011.

[6] Dusabe, J.L. Munda, &Jimoh A.A. "Small Scale Solar Energy System in Rwanda: Status. And Sustainability."Domestic use of energy conference, pp 137-141, 2009.

[7] Rogers A. Messenger, "photovoltaic" floridaatlantic university, 2006.
[8] Retrieved from " http://en.wikipedia.org/wiki/portal:Renewableenergy."

[9] G.D. Rai, "non-conventional energy sources."Khannapublishers 2-B, Nath market, NaiSarak Delhi-m110006. India.2008.

[10] Donald E.O. & David E.C., "Utility Grid-Connected Distributed Power Systems."National solar energy conference.ASES solar, 1996..

Abstract:This work models a 1.5KVA grid connected solar power supply system using a combination of PV array, charge controller, inverter, battery bank, A.C load and installation accessories which work complementarily to capture the best feature of the energy resources and provide the grid-connected location with the highest electricity network quality and reliability. The system operate at minimum running cost, population free environment, noiseless, reliable and provide the convenient of a twenty-four hour power supply. With this system, energy efficiency is achieved by lowering demand using demand response, incorporating temporary and permanent load shifting by back-up and parallel mode respectively. The system was installed at the administrative office of the head of department, electrical and electronic engineering department in Cross River University of technology, Calabar, Nigeria. The total energy is obtained by direct inspection and energy audit. The optimization of the system is based on numerical and analytical modelling and HOMER software package. The sizing results suggest that HOMER software is a powerful, efficient and flexible tool that gives the optimum and cost effective system based on renewable source.
Keywords :Performance analysis, Hybrid power, derating factor, HOMER's software

[1] Tiberiu T. &Alexandru, M., "Optimum Design of wind/PV/Diesel/Batteries Hybrid systems." 2008.

[2] M. Marvwan& H. ImadIbrik, "Techno- economic feasibility of energy supply of remotevillages as Palestine by PV- systems, diesel generators and electric grid," renewable and sustainable energy. Reviews pp 128-138, 2006.

[3] Sambo, A.S., International centre of energy, "Energy and Development Report, Renewable Electricity Action Program," federal ministry of power and steel, Nigeria 2006.

[4] Akpama, E.J.,"Designing a photovoltaic sustained sector: a review of current practice,"domestic use of energy conference, pp 155-160. 2011.

[5] Chimeka I. U, &chineke T. C. "Evaluating The Global Solar Energy Potential AtUturu, Nigeria."International journal of physical sciences.Vol.4(3), pp 115-119, 2011

[6] Dusabe, J.L. Munda, &Jimoh A.A. "Small Scale Solar Energy System In Rwanda: Status. And Sustainability."Domestic use of energy conference, pp 137-141, 2009.

[7] Rogers A. Messenger, " photovoltaic" floridaatlantic university, 2006. [8] G.D. Rai, "non-conventional energy sources."Khanna publishers 2-B,Nath market, NaiSarak Delhi-m110006. India.2008.
[9] Retrieved from " http://en.wikipedia.org/wiki/portal:Renewableenergy."

[10] Donald E.O. & David E.C., "Utility Grid-Connected Distributed Power Systems." National solar energy conference.ASES solar, 1996.