This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
The high cost of power electronic equipment, lower reliability and poor power handling capacity of the semiconductor devices had stalled the deployment of systems based on DC (multi-terminal direct current system (MTDC)) networks. The introduction of voltage source converters (VSCs) for transmission has renewed the interest in the development of large interconnected grids based on both alternate current (AC) and DC transmission networks. Such a grid platform also realises the added advantage of integrating the renewable energy sources into the grid. Thus a grid based on DC MTDC network is a possible solution to improve energy security and check the increasing supply demand gap. An optimal power solution for combined AC and DC grids obtained by the solution of the interior point algorithm is proposed in this study. Multi-terminal HVDC grids lie at the heart of various suggested transmission capacity increases. A significant difference is observed when MTDC grids are solved for power flows in place of conventional AC grids. This study deals with the power flow problem of a combined MTDC and an AC grid. The AC side is modelled with the full power flow equations and the VSCs are modelled using a connecting line, two generators and an AC node. The VSC and the DC losses are also considered. The optimisation focuses on several different goals. Three different scenarios are presented in an arbitrary grid network with ten AC nodes and five converter stations.
References
-
-
1)
-
6. Weigt, H., Jeske, T., Leuthold, F., von Hirschhausen, C.: ‘Take the long way down – integration of large-scale north sea wind using HVDC transmission’, Energy Policy, 2010, 38, (7), pp. 3164–3173 (doi: 10.1016/j.enpol.2009.07.041).
-
2)
-
12. Zhang, X.-P.: ‘Multiterminal voltage-sourced converter-based HVDC models for power flow analysis’, IEEE Trans. Power Syst., 2004, 19, (4), pp. 1877–1884 (doi: 10.1109/TPWRS.2004.836250).
-
3)
-
19. Jiang, H., Ekstrom, A.: ‘Multiterminal hvdc systems in urban areas of large cities’, IEEE Power Deliv., 1998, 13, (4), pp. 1278–1284 (doi: 10.1109/61.714496).
-
4)
-
12. Pizano-Martinez, A., Fuerte-Esquivel, C.R., Ambriz-Perez, H., et al: ‘Modeling of VSC-based HVDC systems for a Newton–Raphson OPF algorithm’, IEEE Trans. Power Syst., 2007, 22, (4), pp. 1794–1803 (doi: 10.1109/TPWRS.2007.907535).
-
5)
-
15. Jovcic, D., Lamont, L., Abbott, K.: ‘Control system design for VSC transmission’, Electr. Power Syst. Res., 2007, 77, (7), pp. 721–729 (doi: 10.1016/j.epsr.2006.06.011).
-
6)
-
14. University of Whasington: ‘Power systems test case archive’. , May 1993.
-
7)
-
X.P. Zhang
.
Multiterminal voltage-sourced converter-based HVDC models for power flow analysis.
IEEE Trans. Power Syst.
,
4 ,
1877 -
1884
-
8)
-
H. Jiang ,
A. EkstroĢm
.
Multiterminal HVDC system in urban areas of large cities.
IEEE Trans. Power Deliv.
,
4 ,
1278 -
1284
-
9)
-
11. Gengyin, L., Ming, Z., Jie, H., Guangkai, L., Haifeng, L.: ‘Power flow calculation of power systems incorporating VSC-HVDC’. Int. Conf. on Power System Technology PowerCon, November 2004, vol. 2, pp. 1562–1566.
-
10)
-
7. Bell, K., Cirio, D., Denis, A., et al: ‘Economic and technical criteria for designing future off-shore HVDC grids’. IEEE PES Innovative Smart Grid Technologies Conf. Europe (ISGT Europe), October 2010, pp. 1–8.
-
11)
-
2. Zhu, J., Booth, C.: ‘Future multi-terminal HVDC transmission systems using voltage source converters’. 45th Int. Universities Power Engineering Conf. (UPEC), September 2010, pp. 1–6.
-
12)
-
3. Van Hertem, D., Ghandhari, M., Delimar, M.: ‘Technical limitations towards a supergrid – a European prospective’. IEEE Int. Energy Conf. and Exhibition (EnergyCon), December 2010, pp. 302–309.
-
13)
-
10. Pizano-Martinez, A., Fuerte-Esquivel, C., Ambriz-Perez, H., Acha, E.: ‘Modeling of VSC-based HVDC systems for a Newton-Raphson OPF algorithm’, IEEE Trans. Power Syst., 2007, 22, (4), pp. 1794–1803 (doi: 10.1109/TPWRS.2007.907535).
-
14)
-
4. Dike, D., Momoh, O.: ‘An integrated AC/DC super-grid system – a mechanism to solving the North American power crisis’. 39th Southeastern Symp. on System Theory SSST, March 2007, pp. 204–209.
-
15)
-
6. Weigt, H., Jeske, T., Leuthold, F., von Hirschhausen, C.: ‘Take the long way down – integration of large-scale north sea wind using HVDC transmission’, Energy Policy, 2010, 38, (7), pp. 3164–3173 (doi: 10.1016/j.enpol.2009.07.041).
-
16)
-
1. Meah, K., Ula, S.: ‘Comparative evaluation of HVDC and HVAC transmission systems’, June 2007, pp. 1–5.
-
17)
-
9. Hans-Peter, N., Ängquist, L.: ‘Perspectives on power electronics and grid solutions for offshore wind farms’, , November 2010.
-
18)
-
15. Jovcic, D., Lamont, L., Abbott, K.: ‘Control system design for VSC transmission’, Electr. Power Syst. Res., 2007, 77, (7), pp. 721–729 (doi: 10.1016/j.epsr.2006.06.011).
-
19)
-
13. Beerten, J., Cole, S., Belmans, R.: ‘A sequential AC/DC power flow algorithm for networks containing multi-terminal VSC HVDC systems’. IEEE PES General Meeting, July 2010, pp. 1–7.
-
20)
-
8. Xu, L., Williams, B., Yao, L.: ‘Multi-terminal DC transmission systems for connecting large offshore wind farms’. IEEE PES General Meeting – Conversion and Delivery of Electrical Energy in the 21st Century, July 2008, pp. 1–7.
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