volume | PIER Journals

Abstract

Leakage fields are one of the main issues in design of electromagnetic systems. Some of these fields close their paths through the core and air, giving rise to non-ideal behavior of the magnetic systems. This paper explains a novel concept of active shielding which consists of two compensation coils in series and generates a counter field opposite to the leakage fields leaking from an iron-core system. As the method is based on physical reasoning of electromagnetic coupled circuit theory, the design criterions for the compensating coils parameters, their number of turns and their adaptation to the systems, were considered. The state of the art is presented by a model which is verified by roots of system characteristic equations, using state equations. In a case study, this method was investigated in a 25kA (125kVA) current injection transformer (CIT) system delivering a secondary current as closely proportioned to the primary current as possible, using finite element method (FEM) simulation. This paper will also push the state of the art by reducing the age effect of the CIT through mechanical force reduction.

1. Robertson, J.-B., E. (T.) A. Parker, B. Sanz-Izquierdo, and J. C. Batchelor, "Electromagnetic coupling through arbitrary apertures in parallel conducting planes," Progress In Electromagnetics Research B, Vol. 8, 29-42, 2008.
doi:10.2528/PIERB08042503 Google Scholar

2. Koontz, R., M. Akemoto, S. Gold, A. Kransnykh, and Z. Wilson, "NLC klystron pulse modulator R&D at SLAC," Proceedings IEEE Conference on Magnetics, 1319-1321, 1998. Google Scholar

3. Li, J., Z.Wang, Y.Wang, M. Gao, and H.Wang, "Effect of mutual inductance on the pulsed current amplification of magnetic field compressors," IEEE Transactions on Magnetics, Vol. 37, No. 1, 489-492, 2001.
doi:10.1109/20.911884 Google Scholar

4. Heydari, H., S. M. Pedramrazi, and F. Faghihi, "The effects of windings current density values on leakage reactance in a 25 kA current injection transformer," IEEE Conference, IPEC, 2005. Google Scholar

5. Buccella, C., M. Feliziani, and A. Prudenzi, "Active shielding design for MV/LV distribution substation," 3rd International Symposium on Electromagnetic Compatibility, 350-353, 2002. Google Scholar

6. Fang, C.-H., S. Zheng, H. Tan, D. Xie, and Q. Zhang, "Shielding effectiveness measurements on enclosures with various apertures by both mode-tuned reverberation chamber and gtem cell methodologies," Progress In Electromagnetics Research B, Vol. 2, 103-114, 2008. Google Scholar

7. Bahadorzadeh, M., M. Naser-Moghadasi, and A. R. Attari, "Improving of shielding effectiveness of a rectangular metallic enclosure with aperture by using extra wall," Progress In Electromagnetics Research Letters, Vol. 1, 45-50, 2008.
doi:10.2528/PIERL07110706 Google Scholar

8. Lei, J.-Z., C. H. Liang, and Y. Zhang, "Study on shielding effectiveness of metallic cavities with apertures by combining parallel FDTD method with windowing technique," Progress In Electromagnetics Research, PIER 74, 85-112, 2007. Google Scholar

9. Faghihi, F. and H. Heydari, "Time domain physical optics for the higher-order FDTD modeling in electromagnetic scattering from 3-D complex and combined multiple materials objects," Progress In Electromagnetics Research, PIER 95, 87-102, 2009. Google Scholar

10. Lipschutz, S. and M. Lipson, Linear Algebra, 3rd edition, Schaum's Outlines, 2000.

11. Chen, B. M., Z. Lin, and Y. Shamash, "Linear System Theory," Birkhauuser, 2004. Google Scholar

12. Heydari, H. and F. Faghihi, "Hybrid winding configuration in high current injection transformers based on EMC issues," IET Electr. Power Appl., Vol. 3, No. 3, 187-196, 2009.
doi:10.1049/iet-epa.2008.0194 Google Scholar

13. Heydari, H., M. Ariannejad, and F. Faghihi, "Simulation and analysis of 25 kA current injection transformer (CIT) with finite element method," IEEE Conference, Melecon, 909-915, 2004. Google Scholar

14. Faghihi, F., H. Heydari, A. Falahati, and Y. A. Easy, "Convolutional codes acting as EMI virtual shields in current injection systems," Progress In Electromagnetics Research, PIER 88, 337-353, 2008. Google Scholar

15. Bedrosian, G., "High-performance computing for finite element methods in low-frequency electromagnetics," Progress In Electromagnetics Research, PIER 07, 57-110, 1993. Google Scholar

16. Baldwin, L. T., I. J. Ykema, L. C. Allen, and L. J. Langston, "Design optimization of high-temperature superconducting power transformers," IEEE Transactions on Applied Superconductivity, Vol. 13, No. 2, 2344-2347, 2003.
doi:10.1109/TASC.2003.813123 Google Scholar

17. Zhang, P.-F., S.-X. Gong, and S. F. Zhao, "Fast hybrid FEM/CRE-UTD method to compute the radiation pattern of antennas on large carriers," Progress In Electromagnetics Research, PIER 89, 75-84, 2009. Google Scholar

18. Wang, Q. and X.-W. Shi, "A an improved algorithm for matrix bandwidth and profile reduction in finite element analysis," Progress In Electromagnetics Research Letters, Vol. 9, 29-38, 2009.
doi:10.2528/PIERL09042305 Google Scholar

19. Tai, C.-C. and Y.-L. Pan, "Finite element method simulation of photoinductive imaging for cracks," Progress In Electromagnetics Research Letters, Vol. 2, 53-61, 2008.
doi:10.2528/PIERL07122807 Google Scholar

20. Vaish, A. and H. Parthasarathy, "Analysis of a rectangular waveguide using finite element method," Progress In Electromagnetics Research C, Vol. 2, 117-125, 2008.
doi:10.2528/PIERC08031801 Google Scholar

21. Hatamzadeh-Varmazyar, S. and M. Naser-Moghadasi, "New numerical method for determining the scattered electromagnetic fields from thin wires," Progress In Electromagnetics Research B, Vol. 3, 207-218, 2008.
doi:10.2528/PIERB07121303 Google Scholar

22. Shiri, A. and A. Shoulaie, "A new methodology for magnetic force calculations between planar spiral coils," Progress In Electromagnetics Research, PIER 95, 39-57, 2009. Google Scholar

23. Formato, R. A., "Central force optimization: A new metaheuristic with applications in applied electromagnetics," Progress In Electromagnetics Research, PIER 77, 425-491, 2007. Google Scholar

Dr. Faramarz Faghihi

Dr. Hossein Heydari