Rashad M. Kamel, A. Chaouachi, Ken Nagasaka
DOI: 10.4236/eng.2011.35059   PDF    HTML     8,991 Downloads   16,613 Views   Citations

Abstract

Today, several types of DGs are connected together and formed a small power system called micro-grid (MG). MG is connected to the primary distribution network and usually operates in normal connecting mode. When a severe fault occurs in the primary distribution network, then the MG will transfer to islanding mode. In this paper a complete model is developed to simulate the dynamic performance of the MG during and subsequent to islanding process. The model contains of a solid oxide fuel cell (SOFC), a single shaft micro turbine, a flywheel, two photovoltaic panels and a wind generator system. All these micro sources are con-nected to the MG through inverters except the wind generation system. The inverters are modeled with two control strategies. The first strategy is PQ control which the inverter will inject a certain active and reactive powers. This type of inverter is used to interface micro turbine, fuel cell and photovoltaic panels to the MG. The second strategy is Vf control. This model is used to interface flywheel will act as the reference bus (slack bus) for the MG when islanding occurs. Two cases are studied: the first case discusses the effect of islanding process on frequency, voltage and active power of all micro sources when the MG imports active and reactive power from the primary distribution network. The second studied case, also, shows the effect of islanding on the previous quantities particularly when the MG exports active and reactive power to the pri-mary distribution network. Results showed that the existence of storage device (flywheel) with appropriate control of its inverter can keep the frequency of the MG and the voltages of all buses within their limited levels. The developed model is built in Matlab® Simulink® environment.

Keywords

MG, Dynamic Performance, Islanding, Inverter and Distributed Generators

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Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	J. Lopes et al., “DD1-Emergency Strategies and Algorithms,” Microgrids project deliverable of task DD1, 2004, Available at http://microgrids.power.ece.ntua.gr
[2]	F. Kanellos et al., “Micro-Grid Simulation during Grid-Connected and Islanded Modes of Operation,” The International Conference on Power Systems Transients (IPST’05), Montereal, 19-23 June 2005, Paper No. IPST05-113.
[3]	A. Hajimiragha, “Generation Control in Small Isolated power Systems,” Master Thesis, Royal Institute of Technology, Department of Electrical Engi-neering, Stockholm, 2005.
[4]	J. Lopes, et al., “Defining Control Strategies for Micro Grids Islanded Operation,” IEEE Transactions on Power Systems, Vol. 21, No. 2, 2006, pp. 916-924.doi:10.1109/TPWRS.2006.873018
[5]	S. Barsali, et al., “Control Techniques of Dispersed Generators to Improve the Continuity of Electricity Supply,” Proceedings of PES Winter Meeting, Vol. 2, 2002, pp. 789-794. doi:10.1109/PESW.2002.985115
[6]	F. Katiraei et al., “Mi-cro-grid Autonomous Operation during and Subsequent to Islanding Process,” Power Engineering Society General Meet-ing, Vol. 20, No. 1, 2005, pp. 248-257. doi:10.1109/TPWRD.2004.835051
[7]	Lasseter, R. and Piagi, P. “ Providing Premium Power through Distributed resources,” Proceedings of the 33rd Hawaii International Conference on System Sciences, Hawaii, 4-7 January 2000, p. 9. doi:10.1109/HICSS.2000.926772
[8]	M. Chan-dorker et al., “Control of Parallel Connected Inverters in Standalone AC Supply System,” IEEE Transactions on Indus-try Applications, Vol. 29, No. 1, 1993, pp. 136-143. doi:10.1109/28.195899
[9]	T. Quoce et al., “Dynamics Analysis of an Insulated Distribution Network,” IEEE Pro-ceedings of Power System Conference and Exposition, Vol. 2, 2004, pp.815-821.doi:10.1109/PSCE.2004.1397644
[10]	R. Caldon, “Analysis of Dynamic Performance of Dispersed Gen-eration Connected through Inverters to Distribution Networks,” Proceedings of 17th International Conference of Electricity Distribution, Barcelona, 12-15 May 2003, pp. 1-5.
[11]	R. M. Kamel and K. Nagasaka, “Design and Implementation of Vari-ous Inverter Controls to Interface Distributed Generators (DGs) in Micro Grids,” Japan Society of Energy and Resources, Ses-sion 6.1, 2009, pp. 60-64.
[12]	R. M. Kamel and K. Nagasaka, “Micro-Grid Dynamic Performance Subsequent to Islanding Process,” Japan Society of Energy and Resources, Session 6.1, 2009, pp. 65-68.
[13]	European Research Project MicroGrids (Online). Available at http://microgrids.power.ece.ntua.gr/