Lightning-Induced Overvoltages Transferred Through Distribution Power Transformers

This paper deals with the calculation of lightning-induced overvoltages on medium-voltage (MV) and low-voltage (LV) distribution networks taking into account the presence of MV-LV distribution transformers and, in particular, the surge transfer through them. The influence of the high-frequency model adopted for the representation of the power transformer on the calculation results is analyzed, with regards to two different models, both identified and validated by means of laboratory measurements: namely, a simple pi of capacitances, and the more complex one introduced by Morched, Marti, and Ottevangers in 1993. Accurate simulation results provide information on the adequacy of both models for the calculations of interest. Additional results, useful to evaluate the expected level of power quality and the benefits achievable by a proper installation of protection devices, are presented making reference to a realistic and complex configuration of an overhead distribution system.

[1]  T. Dhaene,et al.  Advancements in Iterative Methods for Rational Approximation in the Frequency Domain , 2007, IEEE Transactions on Power Delivery.

[2]  A. Semlyen,et al.  Rational approximation of frequency domain responses by vector fitting , 1999 .

[3]  Vladimir A. Rakov,et al.  Testing of the LIOV-EMTP96 Code for Computing Lightning-Induced Currents on Real Distribution Lines: Triggered-Lightning Experiments , 2004 .

[4]  Farhad Rachidi,et al.  Lightning-induced voltages on complex distribution systems: models, advanced software tools and experimental validation , 2004 .

[5]  Mighanda Manyahi,et al.  Simplified model for estimation of lightning induced transient transfer through distribution transformer , 2005 .

[6]  Ashok K. Agrawal,et al.  Transient Response of Multiconductor Transmission Lines Excited by a Nonuniform Electromagnetic Field , 1980 .

[7]  M. Darveniza,et al.  Lightning Protection of Pole Mounted Transformers , 1989, IEEE Power Engineering Review.

[8]  A. Piantini,et al.  Voltage surges transferred to the secondary of distribution transformers , 1999 .

[9]  T. Noda,et al.  Accurate Modeling of Core-Type Distribution Transformers for Electromagnetic Transient Studies , 2002, IEEE Power Engineering Review.

[10]  M. Rubinstein,et al.  An approximate formula for the calculation of the horizontal electric field from lightning at close, intermediate, and long range , 1996 .

[11]  D. J. Wilcox,et al.  Application of modified modal theory in the modelling of practical transformers , 1992 .

[12]  Vernon Cooray,et al.  Horizontal fields generated by return strokes , 1992 .

[13]  Hans Kristian Hoidalen,et al.  Analytical formulation of lightning-induced voltages on multiconductor overhead lines above lossy ground , 2003 .

[14]  S. Rusck.  Protection of Distribution Systems , 1977 .

[15]  L. Weinberg,et al.  Realizability Conditions on n-Port Networks , 1958 .

[16]  A. S. Morched,et al.  A high frequency transformer model for the EMTP , 1993 .

[17]  Bjorn Gustavsen.  Wide band modeling of power transformers , 2004 .

[18]  Luís Miguel Silveira,et al.  A convex programming approach for generating guaranteed passive approximations to tabulated frequency-data , 2004, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems.

[19]  H. Elahi,et al.  Modeling guidelines for fast front transients , 1996 .

[20]  A. Greenwood,et al.  Electrical transients in power systems , 1971 .

[21]  B. Gustavsen,et al.  Enforcing Passivity for Admittance Matrices Approximated by Rational Functions , 2001, IEEE Power Engineering Review.

[22]  Farhad Rachidi,et al.  Interaction of electromagnetic fields with electrical networks generated by lightning , 2003 .

[23]  V.A. Rakov,et al.  Lightning induced disturbances in buried cables - part II: experiment and model validation , 2005, IEEE Transactions on Electromagnetic Compatibility.

[24]  A. Galvan,et al.  A technique for the evaluation of lightning-induced voltages in complex low-voltage power-installation networks , 2001 .

[25]  Amir Mehdi Mousavi.  Frequency-domain equivalents for passive networks , 1999 .

[26]  V.A. Rakov,et al.  Lightning induced disturbances in buried Cables-part I: theory , 2005, IEEE Transactions on Electromagnetic Compatibility.

[27]  P.T.M. Vaessen.  Transformer model for high frequencies , 1988 .

[28]  M. Ianoz,et al.  On lightning return stroke models for LEMP calculations , 1988 .

[29]  B. Gustavsen,et al.  Improving the pole relocating properties of vector fitting , 2006, 2006 IEEE Power Engineering Society General Meeting.

[30]  Alberto Borghetti,et al.  Calculation of voltages induced by nearby lightning on overhead lines terminated on distribution transformers , 1995 .

[31]  Jose R. Marti,et al.  Simplified three-phase transformer model for electromagnetic transient studies , 1995 .

[32]  Farhad Rachidi,et al.  On the Master, Uman, Lin, Standler and the Modified Transmission Line Lightning return stroke current models , 1990 .

[33]  Carlo Alberto Nucci,et al.  Lightning overvoltages in low voltage networks , 1997 .

[34]  Bjorn Gustavsen.  Frequency-dependent modeling of power transformers with ungrounded windings , 2004 .

[35]  A. Piantini,et al.  A Scale Model for the Study of the LEMP Response of Complex Power Distribution Networks , 2007, IEEE Transactions on Power Delivery.

[36]  F. Rachidi,et al.  Mitigation of lightning-induced overvoltages in medium Voltage distribution lines by means of periodical grounding of shielding wires and of surge arresters: modeling and experimental validation , 2004, IEEE Transactions on Power Delivery.