Voltage balancing in low-voltage radial feeders using Scott transformers

Yun Li; Peter A Crossley

Voltage balancing in low-voltage radial feeders using Scott transformers

View Fulltext

Author(s): Yun Li ¹ and Peter A Crossley ¹
- Affiliations: 1: School of Electrical and Electronic Engineering, University of Manchester, Ferranti Building, Manchester M13 9PL, UK
Source: Volume 8, Issue 8, August 2014, p. 1489 – 1498
DOI: 10.1049/iet-gtd.2013.0528 , Print ISSN 1751-8687, Online ISSN 1751-8695

Received 31/07/2013, Accepted 03/02/2014, Revised 18/01/2014, Published 12/03/2014

Increasing use of heat pumps, micro-generation, electric vehicles and energy-saving technologies is expected to cause severe voltage imbalance on low-voltage (LV) radial feeders and deteriorate the power quality seen by single-phase (1Φ) and three-phase (3Φ) LV connected consumers. To solve this problem, a Scott transformer-based balancing technique is used to convert an unbalanced 3Φ supply into a balanced 3Φ supply at either one point on an LV radial feeder or a 3Φ load supply point. Moreover, by replacing the traditional methods of increasing LV cable cross-sections to solve voltage imbalance; or future solutions such as automatic network reconfiguration, the economic cost of operating and upgrading a ‘stressed’ LV feeder can be minimised. A computer simulation study, in which the proposed method is used to balance a typical UK LV network, with varying levels of imbalance, was carried out. Furthermore, a ‘small-scale’ physical voltage balancing system based on the proposed method was constructed and tested in the laboratory. The results obtained from various simulation and experimental scenarios demonstrated that the proposed method can continuously maintain a balanced 3Φ supply by compensating for phase-related voltage dips and surges resulting from variations in 1Φ connected loads.

References

1. 1)
  - 25. Department of Trade and Industry: ‘The impact of small scale embedded generation on the operating parameters of distribution networks’, 2003, p. 10.
2. 2)
  - 7. Chua, K.H., Lim, Y.S., Taylor, P., Morris, S., Wong, J.H.: ‘Energy storage system for mitigating voltage unbalance on low-voltage networks with photovoltaic systems’, IEEE Trans. Power Deliv., 2012, 27, (4), pp. 1783–1790 (doi: 10.1109/TPWRD.2012.2195035).
3. 3)
  - 16. Pillay, P., Manyage, M.: ‘Definitions of voltage unbalance’, IEEE Power Eng. Rev., 2001, 21, (5), pp. 49–51 (doi: 10.1109/MPER.2001.4311362).
4. 4)
  - 1. Department of Energy & Climate Change: ‘Implementing the Climate Change Act 2008: The government's proposal for setting the fourth budget’, 2011, p. 6.
5. 5)
  - 19. Say, M.G.: ‘The performance and design of alternating current machines; transformers, three-phase induction motors and synchronous machines’ (Pitman Press, 1936, 3rd edn. 1958), pp. 66–76.
6. 6)
  - 9. Nicolae, D.V., Siti, M.W., Jimoh, A.A.: ‘LV self-balancing distribution network reconfiguration for minimum losses’. Proc. Conf. IEEE PowerTech, Bucharest, Romania, 2009, pp. 1–6.
7. 7)
  - 4. Aihara, Y., Miyazawa, R., Koizumi, H.: ‘A study on the effect of the Scott transformer on the three-phase unbalance in distribution network with single-phase generators’. Proc. Conf. Power Electronics for Distributed Generation Systems (PEDG), Aalborg, Denmark, 2012, pp. 283–290.
8. 8)
  - 24. Dat, M.T., Wijnhoven, T., Driesen, J.: ‘Fault-tolerant topology of a grid-connected PV inverter coupled by a Scott transformer’. Proc. Conf. Power & Energy (IPEC), Ho Chi Minh City, Vietnam, 2012.
9. 9)
  - 20. Chen, B.K., Guo, B.B.: ‘Three phase models of specially connected transformers’, IEEE Trans. Power Deliv., 1996, 11, (1), pp. 323–330 (doi: 10.1109/61.484031).
10. 10)
  - 5. Li, Y., Crossley, P.: ‘Voltage control on unbalanced LV network using tap changing transformers’. Proc. Conf. Development in Power System Protection, Birmingham, UK, 2012, pp. 1–6.
11. 11)
  - 21. Sheeja, V., Singh, B., Uma, R.: ‘BESS based voltage and frequency controller for standalone wind energy conversion system employing PMSG’. IEEE Industry Applications Society Annual Meeting (IAS 2009), Houston, USA, 2009.
12. 12)
  - 29. Faiz, J., Siahkolah, B.: ‘Implementation of a low-power electronic tap-changer in transformers’, IET Electr. Power Appl., 2008, 2, (6), pp. 362–373 (doi: 10.1049/iet-epa:20070495).
13. 13)
  - 13. Kaipia, T., Peltoniemi, P., Lassila, J., Salonen, P., Partanen, J.: ‘Power electronics in SmartGrids – impact on power system reliability’. SmartGrids for Distribution, CIRED Seminar, Frankfurt, France, 2008, pp. 1–4.
14. 14)
  - 22. Tognolini, M., Rufer, A.C.: ‘A DSP based control for a symmetrical three-phase two-switch PFC-power supply for variable output voltage’. Proc. Conf. IEEE Power Electronics Specialists (PESC), Baveno, Italy, 1996.
15. 15)
  - W.J. Lee , S.W. Choi , C.E. Kim , G.W. Moon . A new PWM-controlled quasi-resonant converter for a high-efficiency PDP sustaining power module. IEEE Trans. Power Electron. , 4 , 1278 - 1290
16. 16)
  - 11. Faruque, M.O., Dinavahi, V.: ‘A tap-changing algorithm for the implementation of ‘Sen’ transformer’, IEEE Trans. Power Deliv., 2007, 22, (3), pp. 1750–1757 (doi: 10.1109/TPWRD.2006.886798).
17. 17)
  - 18. Engineering Recommendation P29: ‘Planning limits for voltage unbalance in the United Kingdom’, 1990.
18. 18)
  - 10. Hahnia, F., Wolfs, P., Ghosh, A.: ‘Voltage unbalance reduction in low voltage feeders by dynamic switching of residential customers among three phases’. Proc. IEEE Power and Energy Society General Meeting, Vancouver, Canada, 2013, pp. 1–5.
19. 19)
  - 15. BS61000: ‘Electromagnetic compatability (EMC) – Part 4–30: Testing and measurement techniques–Power quality measurement methods’, 2009.
20. 20)
  - 17. BS50160: ‘Voltage characteristics of electricity supplied by public electricity networks’, 2010.
21. 21)
  - 8. Shahnia, F., Ghosh, A., Ledwich, G., Zare, F.: ‘Voltage unbalance reduction in low voltage distribution networks with rooftop PVs’. Proc. Conf. 2010 Universities Power Engineering (AUPEC), 2010, pp. 1–5.
22. 22)
  - 6. Chen, J.H., Lee, W.J., Chen, M.: ‘Using a static VAR compensator to balance a distribution system’, IEEE Trans. Ind. Appl., 1999, 35, (2), pp. 298–304 (doi: 10.1109/28.753620).
23. 23)
  - 26. Statutory instruments: ‘The Electricity Safety, Quality and Continuity Regulations 2002’, 2002, p. 14.
24. 24)
  - 27. Haggis, T.: ‘Network design manual’, (e-pub On Central Network, 2006). Available at http://www.eon-uk.com/downloads/network_design_manual.pdf, accessed November 2012.
25. 25)
  - 12. Rekola, J.: ‘DC distribution and power electronics applications in smart grid’. Available at: http://webhotel2.tut.fi/units/set/opetus/kurssit/SET_1520/Materiaalit-2012/Jenni_DC-distribution.pdf, accessed November 2012.
26. 26)
  - 14. Trichakis, P., Taylor, P., Lyons, P.F., Hair, R.: ‘Predicting the technical impacts of high levels of small-scale embedded generators on low-voltage networks’, IET Renew. Power Gener., 2008, 2, (4), pp. 249–262 (doi: 10.1049/iet-rpg:20080012).
27. 27)
  - 2. Hollingworth, D., Lyons, P., Birch, A., Miller, D.: ‘Demonstrating enhanced automatic voltage control for today's low carbon network’. Proc. Integration of Renewables into the Distribution Grid, CIRED 2012 Workshop, Lisbon, Portugal, 2012, pp. 1–4.
28. 28)
  - 3. Chandra, S., Twomey, P., Randles, D.: ‘Impact of PV and load penetration on LV network voltages and unbalance and potential solutions’. Proc. Int. Conf. Electricity Distribution (CIRED), Stockholm, Sweden, 2013.

Login

Not registered yet?

Share

Tools

Login to add to favourites

Key

Voltage balancing in low-voltage radial feeders using Scott transformers

References

Related content