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Technical Description of the Unified Power Flow Controller (UPFC) and Its Potential Variations

  • Ram AdapaEmail author
  • Stig Nilsson
  • Bjarne Andersen
  • Yi Yang
Living reference work entry

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Part of the CIGRE Green Books book series (CIGREGB)

Abstract

The unified power flow controller (UPFC) is a powerful power flow and reactive compensation FACTS controller. It consists of two voltage source converters connected back-to-back with a common DC bus. One of the VSC converters is shunt connected to the AC power system. It is equivalent to a STATCOM, which injects a current into the power system at the point of connection (POC). The other is what is referred to as a Static Synchronous Series Compensator (SSSC), which injects a voltage in series with the transmission line. The injected series voltage can be at any angle with respect to the line current. The injected currents have two parts. First, when the two converters share the same DC bus capacitor, the real power part, which is in phase with the line voltage, delivers or absorbs real power into/from the line. The real power also compensates for the losses in the UPFC. Second, the reactive part, which is in quadrature with the line voltage, emulates an inductive reactance or a capacitive reactance at the point of connection. That is, in an UPFC, the STATCOM can regulate the shunt reactive power at the line connection and also inject or absorb real power to control the DC bus capacitor voltage, thereby facilitating real power transfer between the two converters.

The first installed UPFCs were built with the use of relatively slow switching gate turn-off (GTO) thyristor devices, which were switched at fundamental frequency. This arrangement required the use of harmonically neutralized voltage-sourced converters (HN-VSC) to achieve harmonic cancellation and eliminate or reduce the need for harmonic filters. Currently built VSCs use Modular Multilevel Converters (MMC) that use insulated gate bipolar transistors (IGBTs), which enable design of higher voltage converter valves that eliminate the need for parallel connection of converter modules.

The chapter also provides information about two variations of the UPFC, the Static Synchronous Series Compensator (SSSC) and the Interline Power Flow Controller (IPFC).

References

  1. Ainsworth, J.D., Davies, M, Fitz, P.J., Owens, K.E., Trainer, D.R..: Static Var Compensator (STATCOM) based on single-phase chain circuit converters; IEE Proceedings On-line No. 19982032, 1998CrossRefGoogle Scholar
  2. Allebrod, S., Hamerski, R., Marquardt, R.: New transformerless, scalable modular multilevel converters for HVDC-transmission, IEEE Power Electronics Specialist Conference, PESC2008, June 2008Google Scholar
  3. An, T., Powell, M.T., Thanawala, H.L., Jenkins, N.: Assessment of two different STATCOM configurations for FACTS applications in power systems; POWERCON’98. 1998 International Conference on Power System Technology. Proceedings (Cat. No.98EX151), vol. 1, pp. 307–312, 1998Google Scholar
  4. Ängquist, L.: Synchronous voltage reversal control of thyristor controlled series capacitor. Ph.D. thesis, Royal Institute of Technology, Stockholm (2002)Google Scholar
  5. Bian, J., Ramey, D.G., Nelson, R.J., Edris, A.: A study of equipment sizes and constraints for a unified power flow controller. IEEE Trans. Power Delivery. 12(3), 1385 (1997)CrossRefGoogle Scholar
  6. CIGRE TB 51.: Load Flow Control in High Voltage Power Systems Using FACTS Controllers; section 3.4.8, CIGRE Technical Brochure 51, Jan 1996Google Scholar
  7. CIGRE TB 144.: Static Synchronous Compensator (STATCOM); CIGRE Technical Brochure 144, Aug 2000Google Scholar
  8. CIGRE TB 145, Modeling of Power Electronics Equipment (FACTS) in Load Flow and Stability Programs, CIGRE Technical Brochure. 145, (1999)Google Scholar
  9. CIGRE TB 160.: Unified Power Flow Controller (UPFC); CIGRE Technical Brochure 160, Aug 2000Google Scholar
  10. CIGRE TB 269.: VSC Transmission, CIGRE Technical Brochure 269, Apr 2005Google Scholar
  11. CIGRE TB 371.: Static Synchronous Series Compensator, CIGRE Technical Brochure 371, Feb 2009Google Scholar
  12. CIGRE TB 504.: Voltage and VAr Support in System Operation, CIGRE Technical Brochure 504, Aug 2012Google Scholar
  13. EPRI: Convertible Static Compensator (CSC) for New York Power Authority; EPRI Final Report 1001809, Dec 2003. https://www.epri.com/#/pages/product/000000000001001809/?lang=en-US
  14. Fardanesh B., Henderson M., Gyugyi L., Lam B., Adapa R., Shperling B., Zelingher S., Schauder C., Mountford J., Edris A.: Convertible Static Compensator Application to the New York Transmission System, CIGRE Session Paper 14–103 (1998)Google Scholar
  15. Fortescue, C.L.: Method of symmetrical co-ordinates applied to the solution of polyphase networks; (PDF). AIEE Trans. 37(part II), 1027–1140 (1918)Google Scholar
  16. Grund, C.E., Pollard, E.M., Patel, H.S., Nilsson, S.L.: Power modulation controls for HVDV systems; Cigre paper 14-03, 1984Google Scholar
  17. Gyugyi, L.: Unified power-flow control concept for flexible AC transmission systems; IEE Proceedings C - Generation, Transmission and Distribution. 139(4), (1992)CrossRefGoogle Scholar
  18. Gyugyi, L., Schauder, C.D., Williams, S.L., Torgerson, D.R., Rietman, T.R., Edris, A.: The unified power flow controller: a new approach to power transmission control. IEEE Trans. Power Delivery. 10(2), 1085–1097 (1995)CrossRefGoogle Scholar
  19. Gyugyi, L., Schauder, C.D., Sen, K.K.: Static synchronous series compensator: a solid-state approach to the series compensation of transmission lines. IEEE Trans. Power Delivery. PWRD-12(1), 406–417 (1997)CrossRefGoogle Scholar
  20. Gyugyi, L., Sen, K.K., Schauder, C.D.: The interline power flow controller concept: a new approach to power flow management in transmission systems. IEEE Trans. Power Delivery. 14(3), 1115–1123 (1999)CrossRefGoogle Scholar
  21. Heathcote, M.J.: Phase shifting transformers and quadrature boosters, Section 7.5 pages 7010-710. In: The J & P Transformer Book, Thirteens Edition, Elsevier, Ltd, 2007. https://www.elsevier.com/books/j-and-p-transformer-book/heathcote/978-0-7506-8164-3
  22. Holmes, D.G., Lipo, T.A.: Pulse Width Modulation for Power Converters. IEEE Press and A, Wiley (2003)CrossRefGoogle Scholar
  23. Jacobson, B., Karlsson, P., Asplund, G., Harnefors, L., Jonsson, T.: VSC-HVDC transmission with cascaded two level converters, Cigre paper B4-110, Cigre 2010Google Scholar
  24. Mohan, N., Undeland, T.M., Robbins, W.P.: Gate turn-off thyristors, chapter 24. In: Power Electronics Converters, Applications and Design, 2nd edn, pp. 613–625. Wiley, New York (1995a)Google Scholar
  25. Mohan, N., Undeland, T.M., Robbins, W.P.: Insulated gate bipolar transistors, chapter 25. In: Power Electronics Converters, Applications and Design, 2nd edn, pp. 626–640. Wiley, New York (1995b)Google Scholar
  26. Nam, T., Kim, H., Kim, S., Son, G.T., Chung, Y.H., Park, J.W., Kim, C.K., Hur, K.: Trade-off strategies in designing capacitor voltage balancing schemes for modular multilevel converter HVDC. J. Electr. Eng. Technol. 11, 1921–1718 (2016).  https://doi.org/10.5370/JEET.2016.11.3.1921CrossRefGoogle Scholar
  27. Oates, C., Davidson, C.: 2011. A comparison of two methods of estimating losses in the modular multi-level converter; EPE 2011 – Birmingham. ISBN: 9789075815153Google Scholar
  28. Renz, B.A., Keri, A.J.F., Mehraban, A.S., Kessinger, J.P., Schauder, C.D., Gyugyi, L., Kovalsky, L.J., Edris, A.A.: World’s first unified power flow controller on the AEP system; CIGRE paper 14-107, 1998Google Scholar
  29. Schauder, C., Gernhardt, N., Stacey, E., Lemak, T., Gyugyi, L., Cease, T.W., Edris, A.: Development of a +/− 100 MVAR static condenser for voltage control of transmission systems. IEEE Trans. Power Delivery. 10(3), 1486–1496 (1995)CrossRefGoogle Scholar
  30. Schauder, C., Gernhardt, N., Stacey, E., Lemak, T., Gyugyi, L., Cease, T.W., Edris, A., Wilhelm, M.: TVA TATACOM project: design, installation, and commissioning. CIGRE 1996 Paper: 14–106Google Scholar
  31. Schettler, F., Huang, H., Christl, N.: HVDC transmission systems using voltage sourced converters: design and application. Conference Proceedings, IEEE Summer Meeting 2000, Paper No. 2000 SM-260, vol. 2, pp. 716–720Google Scholar
  32. Sen, K.: SSSC – static synchronous series compensator: theory, modeling, and applications. IEEE Trans. Power Delivery. 13(1), 241–246 (1998)CrossRefGoogle Scholar
  33. Sen, K., Keri, J.F.: UPFC comparison of field results and digital simulation results of voltage sourced-converter based FACTS controllers. IEEE Trans. Power Delivery. 18(1), 300–306 (2003)CrossRefGoogle Scholar
  34. Sen, K.K., Stacey, E.J.: UPFC-unified power flow controller: theory, modeling, and applications; IEEE Transactions on Power Delivery; IEEE Transactions on Power Delivery. 13(4), (1998)CrossRefGoogle Scholar
  35. Zhou, X., Wang, H., Aggarwal, R.K., Beaumont, P.: Performance evaluation of a distance relay as applied to a transmission system with UPFC. IEEE Trans. Power Delivery. 21(3), 1137–1147 (2006)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019 2020

Authors and Affiliations

  • Ram Adapa
    • 1
    Email author
  • Stig Nilsson
    • 2
  • Bjarne Andersen
    • 3
  • Yi Yang
    • 4
  1. 1.Electric Power Research InstitutePalo AltoUSA
  2. 2.Electrical Engineering Practice, ExponentSedonaUSA
  3. 3.Andersen Power Electronic Solutions LtdBexhill-on-SeaUK
  4. 4.State Grid Jiangsu Electric Power Research InstituteNanjingChina

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