Leonid Grcev - Academia.edu (original) (raw)

Papers by Leonid Grcev

GSM base stations are often placed in poles of power transmission lines. Lightning stroke, direct... more GSM base stations are often placed in poles of power transmission lines. Lightning stroke, direct to the tower or at the line near the tower, may induce flashover of the high-voltage (HV) insulators and a subsequent phase to ground fault. The resulting currents distribute to ground over the earth wires and the tower grounding, but also a fraction of the current flows through the metal sheath of the low-voltage (LV) cable to the transformer station (TS) feeding the base station. This may cause dangerous voltages at other customers’ premises served by the TS. Appropriate measures could guarantee safety by installing a LV-to-LV transformer to isolate the HV and the low-voltage/medium-voltage (LV/MV) networks. However, special attention should be paid to the protection of the isolation transformer and the LV cable. This is usually taken care of by suitable over-voltage arrestors. To optimize such protection better knowledge of the transient current distribution during the transient peri...

IEEE Transactions on Power Delivery

IEEE Transactions on Power Delivery

IEEE Transactions on Electromagnetic Compatibility

IEEE Transactions on Electromagnetic Compatibility

ABSTRACT Several approximate formulas for the per-unit-length inductance of horizontal buried bar... more ABSTRACT Several approximate formulas for the per-unit-length inductance of horizontal buried bare conductors are often used in the modern literature, with different approaches in considering the effects of the earth surface. In this paper we derive a new expression for the external inductance, based on the exact expressions of the magnetic field for a dc horizontal electric dipole. We also examine the use of the derived expression in high-frequency analysis of horizontal grounding electrodes, for several practical cases.

IEEE Transactions on Electromagnetic Compatibility, 2015

2010 Conference Proceedings Icecom 20th International Conference on Applied Electromagnetics and Communications, Sep 1, 2010

Abstract The paper presents an image and a transmission line model of a horizontal thin-wire cond... more Abstract The paper presents an image and a transmission line model of a horizontal thin-wire conductor above a two-layer soil at high frequencies. In contrast to the classical quasi-static image approach, the presented image model involves the propagation effect. A modified transmission line model for the above problem is also presented. This approach involves an equivalent resistivity of two-layer soil within the classical transmission line theory. The verification of the proposed image and transmission line models is done by ...

This paper presents rigorous electromagnetic field approach for full wave analysis of the groundi... more This paper presents rigorous electromagnetic field approach for full wave analysis of the grounding performance of vertical ground rod penetrating two-layer soil. Mathematically, the model is formulated by mixed potential integral equation with exact Green's functions of stratified medium that involves Sommerfeld type integrals. Computationally, the model is based on the Galerkin approach in the method of moments and direct

Widespread use of the mobile communication devices has given rise to the public concern about the... more Widespread use of the mobile communication devices has given rise to the public concern about the possible dangerous effects of electromagnetic radiation on human health. Major fears are related to the presence of mobile phone base stations near residential buildings. In this paper we analyze spatial distribution of the electromagnetic fields at several sites with different installations of base stations, that are usual in urban areas. Measurements are performed indoors and outdoors, in areas accessible to the general public. We also give brief analysis on the safety regulations for public exposure to radiofrequency non–ionizing radiation. Such analysis can contribute for better understanding of the safety regulations and expected exposure levels near base stations.

IEEE Transactions on Industry Applications, 2015

IEEE 1997, EMC, Austin Style. IEEE 1997 International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.97CH36113), 1997

Wire-line communication installations serving telephone subscribers in the zone of influence of f... more Wire-line communication installations serving telephone subscribers in the zone of influence of fault-produced ground potential rise (GPR) in an area surrounding the high voltage substations require special protection. In urban areas the substation grounding system may be connected to or located near to a large and complex network of conductors composed of metal sheaths of power and telecommunication cables, pipes

Twenty-Third International Telecommunications Energy Conference. INTELEC 2001, 2001

2003 IEEE Bologna Power Tech Conference Proceedings,, 2003

GSM base stations are often placed in the poles of power transmission lines. Such base stations a... more GSM base stations are often placed in the poles of power transmission lines. Such base stations are usually powered from the low-voltage network through an isolating transformer to separate the high- and low-voltage networks. The isolating transformer serves to ensure security at other customers' premises especially in case of lightning stroke at the line, which is a frequent cause of

2003 IEEE International Symposium on Electromagnetic Compatibility, 2003. EMC '03., 2003

MELECON '98. 9th Mediterranean Electrotechnical Conference. Proceedings (Cat. No.98CH36056), 1998

ABSTRACT The increased number of electromagnetic field sources and the growing use of electronic ... more ABSTRACT The increased number of electromagnetic field sources and the growing use of electronic equipment in almost all human working areas, makes human life dependent on the quality of products that produce and/or use electromagnetic energy. Therefore, an important parameter of equipment quality becomes its capability of efficient utilization without destroying the quality of the living environment and/or causing health problems. A monitoring system for visualization of electromagnetic field influences on humans, currently under development, enables the design of electric devices and the testing of electromagnetic field influences on humans who are nearby and/or use electric devices. The system and its characteristics are presented in this paper

2003 IEEE International Symposium on Electromagnetic Compatibility, 2003. EMC '03., 2003

This paper presents the ongoing research results of the high frequency grounding system analysis ... more This paper presents the ongoing research results of the high frequency grounding system analysis in two-layer soil structure. On the basis of rigorous electromagnetic field theory, which involves Sommerfeld's integrals, the mathematical model is formulated by the mixed potential integral equation (MPIE). Detailed analysis of a high frequency performance of a typical short and long horizontal grounding conductor placed in the upper layer is given. It is shown that because of the presence of two distinct layers the current distribution is not only function of frequency, but also a function of the reflection factor and the upper layer height

Proceedings of Intelec 93: 15th International Telecommunications Energy Conference, 1993

Signal and control cables are often placed in closed metal tubes for optimal protection from indu... more Signal and control cables are often placed in closed metal tubes for optimal protection from induced overvoltages in case of lightning. The key parameter is the current distribution along the tube, which is closely related to the currents flowing through the earthings to which the tube is connected. A careful analysis of the current distribution has to be made prior to the coupling study. A computer model based on electromagnetic field theory, which takes into account the interactions between different parts of the conductors is described. The distribution of the current is assessed in both frequency and time domains. The influence of a shield wire placed near the tube is also analyzed

International Symposium on Electromagnetic Compatibility, 1992

2008 International Symposium on Electromagnetic Compatibility - EMC Europe, 2008

GSM base stations are often placed in poles of power transmission lines. Lightning stroke, direct... more GSM base stations are often placed in poles of power transmission lines. Lightning stroke, direct to the tower or at the line near the tower, may induce flashover of the high-voltage (HV) insulators and a subsequent phase to ground fault. The resulting currents distribute to ground over the earth wires and the tower grounding, but also a fraction of the current flows through the metal sheath of the low-voltage (LV) cable to the transformer station (TS) feeding the base station. This may cause dangerous voltages at other customers’ premises served by the TS. Appropriate measures could guarantee safety by installing a LV-to-LV transformer to isolate the HV and the low-voltage/medium-voltage (LV/MV) networks. However, special attention should be paid to the protection of the isolation transformer and the LV cable. This is usually taken care of by suitable over-voltage arrestors. To optimize such protection better knowledge of the transient current distribution during the transient peri...

IEEE Transactions on Power Delivery

IEEE Transactions on Power Delivery

IEEE Transactions on Electromagnetic Compatibility

IEEE Transactions on Electromagnetic Compatibility

ABSTRACT Several approximate formulas for the per-unit-length inductance of horizontal buried bar... more ABSTRACT Several approximate formulas for the per-unit-length inductance of horizontal buried bare conductors are often used in the modern literature, with different approaches in considering the effects of the earth surface. In this paper we derive a new expression for the external inductance, based on the exact expressions of the magnetic field for a dc horizontal electric dipole. We also examine the use of the derived expression in high-frequency analysis of horizontal grounding electrodes, for several practical cases.

IEEE Transactions on Electromagnetic Compatibility, 2015

2010 Conference Proceedings Icecom 20th International Conference on Applied Electromagnetics and Communications, Sep 1, 2010

Abstract The paper presents an image and a transmission line model of a horizontal thin-wire cond... more Abstract The paper presents an image and a transmission line model of a horizontal thin-wire conductor above a two-layer soil at high frequencies. In contrast to the classical quasi-static image approach, the presented image model involves the propagation effect. A modified transmission line model for the above problem is also presented. This approach involves an equivalent resistivity of two-layer soil within the classical transmission line theory. The verification of the proposed image and transmission line models is done by ...

This paper presents rigorous electromagnetic field approach for full wave analysis of the groundi... more This paper presents rigorous electromagnetic field approach for full wave analysis of the grounding performance of vertical ground rod penetrating two-layer soil. Mathematically, the model is formulated by mixed potential integral equation with exact Green's functions of stratified medium that involves Sommerfeld type integrals. Computationally, the model is based on the Galerkin approach in the method of moments and direct

Widespread use of the mobile communication devices has given rise to the public concern about the... more Widespread use of the mobile communication devices has given rise to the public concern about the possible dangerous effects of electromagnetic radiation on human health. Major fears are related to the presence of mobile phone base stations near residential buildings. In this paper we analyze spatial distribution of the electromagnetic fields at several sites with different installations of base stations, that are usual in urban areas. Measurements are performed indoors and outdoors, in areas accessible to the general public. We also give brief analysis on the safety regulations for public exposure to radiofrequency non–ionizing radiation. Such analysis can contribute for better understanding of the safety regulations and expected exposure levels near base stations.

IEEE Transactions on Industry Applications, 2015

IEEE 1997, EMC, Austin Style. IEEE 1997 International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.97CH36113), 1997

Wire-line communication installations serving telephone subscribers in the zone of influence of f... more Wire-line communication installations serving telephone subscribers in the zone of influence of fault-produced ground potential rise (GPR) in an area surrounding the high voltage substations require special protection. In urban areas the substation grounding system may be connected to or located near to a large and complex network of conductors composed of metal sheaths of power and telecommunication cables, pipes

Twenty-Third International Telecommunications Energy Conference. INTELEC 2001, 2001

2003 IEEE Bologna Power Tech Conference Proceedings,, 2003

GSM base stations are often placed in the poles of power transmission lines. Such base stations a... more GSM base stations are often placed in the poles of power transmission lines. Such base stations are usually powered from the low-voltage network through an isolating transformer to separate the high- and low-voltage networks. The isolating transformer serves to ensure security at other customers' premises especially in case of lightning stroke at the line, which is a frequent cause of

2003 IEEE International Symposium on Electromagnetic Compatibility, 2003. EMC '03., 2003

MELECON '98. 9th Mediterranean Electrotechnical Conference. Proceedings (Cat. No.98CH36056), 1998

ABSTRACT The increased number of electromagnetic field sources and the growing use of electronic ... more ABSTRACT The increased number of electromagnetic field sources and the growing use of electronic equipment in almost all human working areas, makes human life dependent on the quality of products that produce and/or use electromagnetic energy. Therefore, an important parameter of equipment quality becomes its capability of efficient utilization without destroying the quality of the living environment and/or causing health problems. A monitoring system for visualization of electromagnetic field influences on humans, currently under development, enables the design of electric devices and the testing of electromagnetic field influences on humans who are nearby and/or use electric devices. The system and its characteristics are presented in this paper

2003 IEEE International Symposium on Electromagnetic Compatibility, 2003. EMC '03., 2003

This paper presents the ongoing research results of the high frequency grounding system analysis ... more This paper presents the ongoing research results of the high frequency grounding system analysis in two-layer soil structure. On the basis of rigorous electromagnetic field theory, which involves Sommerfeld's integrals, the mathematical model is formulated by the mixed potential integral equation (MPIE). Detailed analysis of a high frequency performance of a typical short and long horizontal grounding conductor placed in the upper layer is given. It is shown that because of the presence of two distinct layers the current distribution is not only function of frequency, but also a function of the reflection factor and the upper layer height

Proceedings of Intelec 93: 15th International Telecommunications Energy Conference, 1993

Signal and control cables are often placed in closed metal tubes for optimal protection from indu... more Signal and control cables are often placed in closed metal tubes for optimal protection from induced overvoltages in case of lightning. The key parameter is the current distribution along the tube, which is closely related to the currents flowing through the earthings to which the tube is connected. A careful analysis of the current distribution has to be made prior to the coupling study. A computer model based on electromagnetic field theory, which takes into account the interactions between different parts of the conductors is described. The distribution of the current is assessed in both frequency and time domains. The influence of a shield wire placed near the tube is also analyzed

International Symposium on Electromagnetic Compatibility, 1992

2008 International Symposium on Electromagnetic Compatibility - EMC Europe, 2008