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Izadi M.,UPM University | Izadi M.,Islamic Azad University at Firoozkooh | Ab Kadir M.Z.A.,UPM University | Hajikhani M.,Aryaphase Company
IET Conference Publications | Year: 2013

The ground reflection at channel base is as an important factor on the values of lightning electromagnetic fields and lightning induced voltage on the power line that is due to difference between the return stroke channel and the ground impedances. In this paper, the effects of ground reflection factor on the values of lightning return stroke currents at different heights along lightning channel and also lightning electromagnetic fields are considered and the results are discussed accordingly.


Izadi M.,University Putra Malaysia | Ab Kadir M.Z.A.,Islamic Azad University at Firoozkooh | Hajikhani M.,Aryaphase Company
Journal of Electrical Engineering and Technology | Year: 2013

Lightning electromagnetic fields are important issues for the evaluation of lightning induced overvoltage on power lines and for setting the appropriate protection level for power networks. Such electromagnetic fields are strongly dependent on lightning return stroke currents at different heights along the lightning channel. On the other hand, the ground reflection factor due to the difference between the return stroke channel impedance and the equivalent ground impedance at channel base can have an effect on the shape of the return stroke currents by entering additional reflected currents into the channel. In this paper, the effect of the ground reflection factor on the return stroke currents at different heights along a channel and the electromagnetic fields associated with the lightning channel at close distances are considered. Moreover, the behavior of the electromagnetic fields versus the reflection factor changes and the radial distance changes are considered and the results are discussed accordingly. The results illustrate that the reflection factor has a direct relationship with the values of the electromagnetic fields while this is usually ignored in earlier studies.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Izadi M.,Aryaphase Company | Ab Kadir M.Z.A.,University Putra Malaysia | And 2 more authors.
Jurnal Teknologi (Sciences and Engineering) | Year: 2013

In this paper, the relationship between current front time and front time of vertical electric field due to lightning channel at non perfect ground is considered. Results showed that the peak of simulated vertical electric fields under non perfect ground conductivity condition is decreased compared to the corresponding field at perfect ground while the front time of field is increased at non perfect case compared to the perfect one. Likewise, the effect of ground conductivity on the peak and front time of simulated vertical electric field is considered and the results are discussed accordingly. © 2013 Penerbit UTM Press. All rights reserved.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,Aryaphase Company
Mathematical Problems in Engineering | Year: 2014

The analytical field expressions are proposed to estimate the electromagnetic fields associated with vertical lightning channel at an observation point directly in the time domain using current and geometrical parameters. The proposed expressions embrace a large number of channel base current functions and widely used engineering current models. Moreover, they can be joined with different coupling models for evaluation of lightning induced voltage when they provide different required field components directly in the time domain. The data from measured fields and simulated fields from previous works were employed to validate the proposed field expressions. The simulated results were compatible with both computed field values from previous studies and the measured fields. © 2014 Mahdi Izadi et al.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,Aryaphase Company
Journal of Electrical Engineering and Technology | Year: 2014

Lightning induced voltage is a major factor that causes interruptions on distribution lines. In this paper, analytical expressions are proposed to evaluate a lightning induced voltage on power lines directly in the time domain without the need to apply any extra conversions. The proposed expressions can consider the widely used current functions and models in contrast to the earlier analytical expressions which had a number of limitations related to the simplification of the channel base current and the current along the lightning channel. The results show that the simulated values based on the proposed method are in good agreement with the previous studies and the proposed expressions can be used for optimizing the insulation and protection level of existing and new lines being designed.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,Aryaphase Company
Journal of Electrical Engineering | Year: 2014

In this paper, general electric field expressions are proposed to consider the effect of channel base ground reflections and ground conductivity on the electric field components due to lightning. The proposed method can support different current models and functions directly in the time domain without the need to apply any extra conversions. The proposed method is applied on a sample of measured channel base current from triggered lightning experiment and the results are discussed accordingly. The results show that the ground reflection and ground conductivity can have an effect on the peak values of the electric fields whereby the electric field components have a great effect on the widely used coupling models. © 2014 FEI STU.


Izadi M.,Islamic Azad University at Firoozkooh | Izadi M.,University Putra Malaysia | Ab Kadir M.Z.A.,Islamic Azad University at Firoozkooh | Hajikhani M.,Aryaphase Company
2014 International Conference on Lightning Protection, ICLP 2014 | Year: 2014

In this paper an inverse procedure algorithm in the time domain is proposed to evaluate the wave shape of the lightning return stroke current along a lightning channel using measured electromagnetic fields obtained at different distances with respect to the lightning channel. Moreover, the proposed method was applied on an actual sample of lightning current and the results discussed accordingly. The proposed method takes into consideration all the field components which cover the full shape of the current. Thus the method can be helpful for preparing a lightning current data bank and setting a proper protection level for a power system based on local information. © 2014 IEEE.


Izadi M.,Islamic Azad University at Firoozkooh | Izadi M.,University Putra Malaysia | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,Aryaphase Company
2014 International Conference on Lightning Protection, ICLP 2014 | Year: 2014

Considering the performance of insulators versus lightning effects is an important issue for insulation coordination in distribution lines. In this paper, the performance of a polymer insulator (33 kV) versus lightning induced voltage under different weather conditions was considered in transient domain and the profile of the voltage and fields along the insulator were evaluated and the results discussed accordingly. The results showed that the lightning induced voltage can have a great effect on the profile of the voltage and the fields along an insulator and also the weather conditions can profoundly affect the protection level of an insulator. Therefore, in order to set an appropriate protection level on the distribution line, consideration of the behaviour of an insulator under different weather conditions based on local data can be helpful. © 2014 IEEE.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,University Putra Malaysia | Hajikhani M.,Aryaphase Company
Applied Computational Electromagnetics Society Journal | Year: 2014

In this paper, an inverse procedure algorithm is proposed to evaluate lightning return stroke current wave shapes at different heights along a lightning channel, as well as the ground reflection factor using measured electromagnetic fields at an observation point while the current model can be set for different models based on the general form of the engineering current models. In order to validate the proposed method, a set of measured electromagnetic fields are used as the input parameters for the proposed algorithm. Likewise, the evaluated channel base current is compared to the corresponding measured current and also the simulated fields at another observation point (based on the evaluated current) are compared to the corresponding measured fields and the results are discussed accordingly. The results show that the evaluated current and fields based on the proposed method are in good agreement with respect to the corresponding measured values. © 2014 ACES.


Izadi M.,University Putra Malaysia | Izadi M.,Islamic Azad University at Firoozkooh | Izadi M.,Aryaphase Company | Ab Kadir M.Z.A.,University Putra Malaysia | Hajikhani M.,University Putra Malaysia
Proceedings of the 2013 IEEE 7th International Power Engineering and Optimization Conference, PEOCO 2013 | Year: 2013

In this paper, the influence of lightning induced voltages (LIV) on distribution lines (DL) is considered and the effects of channel and also geometrical parameters on the values of LIV are processed and the results are discussed accordingly. The results show that the peak values LIV are more dependent on the current peak, return stroke velocity and the conductor height with a linear relationship. Therefore, in order to design or improve distribution networks, the behaviour of LIV under different channel and geometrical conditions can be useful for setting and optimizing the appropriate protection level on the lines. © 2013 IEEE.

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