Enhancing Frequency of Grid-connected Wind Farm using Energy Capacitor System and Trap RC Shunt Damper Strategies

Kenneth E Okedu


In this paper, a combination of the conventional energy capacitor system and a proposed two-trap Resistor Capacitor (RC) shunt damper circuitry is used to stabilize a grid network made up of fixed speed wind turbines, steam turbines and hydro turbines. The energy storage system is connected to the terminals of the wind farm and has the capability of stabilizing the grid network during periods of wind speed change. The two-trap damper has the ability to mitigate the mechanical vibration of the wind turbine and increase its output and rotor speed acceleration during disturbances, so the turbine speed is reduced.  Simulations were run using Power System Computer Aided Design and Electromagnetic Transient Including DC (PSCAD/EMTDC) environment, for scenarios where grid frequency control was not implemented and when frequency control was employed using the energy storage device. A further investigation was carried out in enhancing the performance of the grid network considering the proposed two-trap shunt DC damper control topology. The results show the improved performance of the variables of the wind turbine and the entire grid network during dynamics, due to the coordinated control strategies of the two-trap RC circuit and the energy capacitor system employed. 

Citation: Okedu, K. E. (2018). Enhancing Frequency of Grid-connected Wind Farm using Energy Capacitor System and Trap RC Shunt Damper Strategies. Trends in Renewable Energy, 4, 96-110. DOI: 10.17737/tre.2018.4.2.0070


Wind energy; Wind farm; Frequency; Grid; Wind turbine; Filters; RC damper

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Popović-Gerber, J., Oliver, J. A., Cordero, N., Harder, T., Cobos, J. A., Hayes, M., O'Mathuna, S. C., Prem, E. (2012). Power electronics enabling efficient energy usage: energy savings potential and technological challenges. IEEE Trans. Power Electronic. 27(5), 2338 – 2353.

Okedu, K. E. (2016). Enhancing DFIG wind turbine during three-phase fault using parallel interleaved converters and dynamic resistor. IET Renewable Power Generation. 10 (6), 1211-1219.

Okedu, K. E., Muyeen, S. M., Takahashi R., and Tamura, J. (2011). Protection schemes for DFIG considering rotor current and DC-link voltage. 24th IEEE-ICEMS (International Conference on Electrical Machines and System), Beijing, China, 1-6. DOI: 10.1109/ICEMS.2011.6073453

Ramesh S., and Krishnan, A. (2011). Stabilization of frequency deviation in an AC-DC interconnected power systems using supervisory fuzzy controller. Tamkang Journal of Science and Engineering. 14(4), 341-349.

Gross, G., and Lee J. W. (2001). Analysis of load frequency control performance assessment criteria. IEEE Transactions on Power Systems. 16, 520-525.

Venkata P. B., Jayaram K. S. V. (2008) Load frequency control for two area interconnected power system using robust genetic algorithm controller. Journal of theoretical and applied information technology. 4(12), 1204-1221. http://www.jatit.org/volumes/research-papers/Vol4No12/7Vol4No12.pdf (accessed on 6/1/2018)

Hulst, D., Fernadez, M., et al. (2015). Voltage and frequency control for future power systems: the Electra IRP Proposal. Proceedings International symposium in smart electric distribution systems and technologies, 245-250. DOI: 10.1109/SEDST.2015.7315215

Jagathessan K., and Dey N. (2015). Artificial intelligence in performance analysis of load frequency control in thermal wind hydropower system. International Journal of Advanced Computer Science and Applications. 6 (7), 203-212.

Messikh, T., Mekhilef S., and Rahim, N. A. (2008). Adaptive notch filter for harmonic current mitigation. World Academy of Science Engineering and Technology. 22, 907-913.

Saiteja K., and Krishnarayalu, M. S. (2015). Load frequency control of two area smart grid. International Journal of Computer Applications. 117(14), 1-9.

Wilches-Bernal F., Chow, J. H., and Sanchez-Gasca, J. J. (2015). A fundamental study of applying wind turbines for power system frequency control. IEEE Transactions on Power Systems. 31(2), 1496-1505.

Liserre, M., Blaabjerg, F., and Hansen, S. (2005). Design and control of an LCL-filter-based three-phase active rectifier, IEEE Trans. on Ind. Applications. 41(5), 1281–1291.

Patel, Y., Pixler, D., and Nasiri, A. (2010). Analysis and design of trap and LCL filters for active switching converters. IEEE Int. Symp. on Ind. Electron. 638–643. DOI: 10.1109/ISIE.2010.5637475

Dannehl, J., Liserre, M., and Fuchs, F. W. (2011). Filter-based active damping of voltage source converters with LCL filter. IEEE Trans. Ind. on Electronic. 58(8), 3623–3633.

Teodorescu, R., Blaabjerg, F., Liserre, M., and Dell’Aquila, A. (2003). A stable three-phase LCL-filter based active rectifier without damping. 38th IAS Annual Meeting on Conference Record of the Industry Applications Conference, 3, 1552–1557. DOI: 10.1109/IAS.2003.1257762

Beres, R., Wang, X., Blaabjerg, F., Bak, C. L., and Liserre, M. (2014). A review of passive filters for grid-connected voltage source converters. 2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014. 2208–2215. DOI: 10.1109/APEC.2014.6803611

Friedrich L., and Gautschi, M. (2009). Grid stabilization control and frequency regulation for inverted connected distribution renewable source. Master Thesis, Department of Electrical and Computer Engineering, Power System Research, University of Wisconsin- Madison. https://pdfs.semanticscholar.org/b478/00585681f7880da0c2b7ae02222efca9cf78.pdf (accessed on 6/1/2018)

Okedu, K. E. (2017). Effect of ECS low pass filter timing on grid frequency dynamics of a power network considering wind energy penetration. IET Renewable Power Generation. 11(9), 1194-1199.

Okedu, K. E. (2017). Improving grid frequency dynamics of synchronous generators considering wind energy penetration. IEEE International Electric Machines and Drives Conference (IEMDC), Paper ID 112, May 21-24, Miami, Florida, USA. DOI: 10.1109/IEMDC.2017.8001865

Okedu, K. E., Muyeen, S. M., Takahashi, R., and Tamura, J. (2012). Wind farms fault ride through using DFIG with new protection scheme. IEEE Transactions on Sustainable Energy. 3(2), 242-254, April. DOI: 10.1109/TSTE.2011.2175756

Manitoba HVDC research center, (2004). PSCAD/EMTDC Manuals. https://hvdc.ca/uploads/knowledge_base/pscad_users_guide_v4_6.pdf?t=1497534232, and https://hvdc.ca/uploads/knowledge_base/emtdc_users_guide_v4_6.pdf?t=1497534178 (accessed on 6/1/2018)

Usluer, S. N. (2014). Switch mode converter based damping of PWM converter with LCL type filter for grid interface of renewable energy. Thesis, Natural and Applied Science, Middle East Technical University. http://etd.lib.metu.edu.tr/upload/12618359/index.pdf (accessed on 6/1/2018)

Beres, R., Wang X., and Blaabjerg, F. (2015). Improved passive-damped LCL filter to enhance stability in grid-connected voltage source converters. Proceedings of the 23rd International Conference and Exhibition on Electricity Distribution, Lyon France, 15-18 June, Paper 1093.

IEEE. (1993). IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems. IEEE Std 519-1992, 1-112. https://ieeexplore.ieee.org/document/210894/ (accessed on 6/1/2018)

Dugan, R. C. McGranaghan, M. F., Santoso, S., Beaty, H.W. (2012). Electrical power systems quality, Mc Graw Hill, New York, United States of America, 290.

Wu, W., He, Y., and Blaabjerg, F. (2012). An LCL power filter for single-phase grid-tied inverter. IEEE Trans. on Power Electronic. 27(2), 782–789.

DOI: http://dx.doi.org/10.17737/tre.2018.4.2.0070


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