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Thursday, 10 August 2017

Power Quality Improvement In Transmission Systems Using DPFC


1.      AC–DC power conversion
2.      Load flow control
3.      Power electronics
4.      Power semiconductor devices
5.      Power system control
6.      Power-transmission control



Figure 1.DPFC configuration


Figure 2.Supply voltage during sag condition

Figure 3. Injected voltage during sag condition

Figure 4. Elimination of sag voltage

Figure 5. Supply voltage during swell

Figure 6. Injected voltage for swell

Figure 7. Elimination of swell voltage

The series converter of the DPFC employs the DFACTS concept, which uses multiple small single-phase converters instead of one large-size converter. It is proved that the shunt and series converters in the DPFC can exchange active power at the third-harmonic frequency, and the series converters are able to inject controllable active and reactive power at the fundamental frequency. The DPFC is also used to improving power quality problems such as sag and swell. The reliability of the DPFC is greatly increased because of the redundancy of the series converters. The total cost of the DPFC is also much lower than the UPFC, because no high-voltage isolation is required at the series converter part and the rating of the components of is low.

[1] D. Divan and H. Johal, “Distributed facts-A new concept for realizing grid power flow control,” in IEEE 36th Power Electron. Spec. Conf. (PESC), 2005, pp. 8–14.
[2] K K. Sen, “Sssc-static synchronous series compensator: Theory, modeling, and application”,IEEE Trans. Power Del., vol. 13, no. 1, pp 241–246, Jan. 1998.
[3] L.Gyugyi, C.D. Schauder, S. L.Williams, T. R. Rietman, D. R. Torgerson, and A. Edris, “The unified power flow controller: A new approach to power transmission control”, IEEE Trans. Power Del., vol. 10, no. 2, pp. 1085– 1097, Apr. 1995.
[4] M. D. Deepak, E. B. William, S. S. Robert, K. Bill, W. G. Randal, T. B. Dale, R. I. Michael, and S. G. Ian, “A distributed static series compensator system for realizing active power flow control on existing power lines”, IEEE Trans. Power Del., vol. 22, no. 1, pp. 642–649, Jan.2007.

[5] M. Mohaddes, A. M. Gole, and S. Elez, “Steady state frequency response of statcom”, IEEE Trans. Power Del., vol. 16, no. 1, pp. 18–23, Jan. 2001.