TY  - JOUR
AU  - Brajović, Dragan
AU  - Jokanović, Bojan
AU  - Bebić, Milan
AU  - Kartalović, Nenad
AU  - Nikezić, Dušan P.
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10642
AB  - The study aims to achieve a simple, reliable, and significant lifetime extension of the high-voltage asynchronous machine in relation to the voltage endurance test. To achieve this goal, the focus was on achieving longer-lasting and more stable insulation of the stator package of an asynchronous machine. Longer-lasting and more stable insulation of a stator is achieved by reinforcing the weak points on its prefabricated multiturn coils. These reinforcements were performed with standard insulating materials that are used for the production of the prefabricated multiturn coils (because there is no data regarding the long-term behavior of new materials that show some better properties in laboratories, but only during short-term tests). With such reinforced weak spots based on prefabricated models, they were made by the classical procedure with the use of standardized tools. To track the effects of the improvement of the insulation characteristics of a stator, an algorithm was developed based on the law of increasing probability and the determination of lifetime curves to the voltage endurance test. The lifetime curves were determined by the method of increasing voltage with the transformation of the obtained results to the corresponding results by the constant voltage method. The applied algorithm that was formed for this study, had been verified with statistical reliability of 95%. The combined measurement uncertainty of the measurement procedure was about 5%.
T2  - Electrical Engineering
T1  - Lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test
VL  - 105
SP  - 1643
EP  - 1653
DO  - 10.1007/s00202-023-01767-w
ER  - 

@article{
author = "Brajović, Dragan and Jokanović, Bojan and Bebić, Milan and Kartalović, Nenad and Nikezić, Dušan P.",
year = "2023",
abstract = "The study aims to achieve a simple, reliable, and significant lifetime extension of the high-voltage asynchronous machine in relation to the voltage endurance test. To achieve this goal, the focus was on achieving longer-lasting and more stable insulation of the stator package of an asynchronous machine. Longer-lasting and more stable insulation of a stator is achieved by reinforcing the weak points on its prefabricated multiturn coils. These reinforcements were performed with standard insulating materials that are used for the production of the prefabricated multiturn coils (because there is no data regarding the long-term behavior of new materials that show some better properties in laboratories, but only during short-term tests). With such reinforced weak spots based on prefabricated models, they were made by the classical procedure with the use of standardized tools. To track the effects of the improvement of the insulation characteristics of a stator, an algorithm was developed based on the law of increasing probability and the determination of lifetime curves to the voltage endurance test. The lifetime curves were determined by the method of increasing voltage with the transformation of the obtained results to the corresponding results by the constant voltage method. The applied algorithm that was formed for this study, had been verified with statistical reliability of 95%. The combined measurement uncertainty of the measurement procedure was about 5%.",
journal = "Electrical Engineering",
title = "Lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test",
volume = "105",
pages = "1643-1653",
doi = "10.1007/s00202-023-01767-w"
}

Brajović, D., Jokanović, B., Bebić, M., Kartalović, N.,& Nikezić, D. P.. (2023). Lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test. in Electrical Engineering, 105, 1643-1653.
https://doi.org/10.1007/s00202-023-01767-w

Brajović D, Jokanović B, Bebić M, Kartalović N, Nikezić DP. Lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test. in Electrical Engineering. 2023;105:1643-1653.
doi:10.1007/s00202-023-01767-w .

Brajović, Dragan, Jokanović, Bojan, Bebić, Milan, Kartalović, Nenad, Nikezić, Dušan P., "Lifetime extension of the high voltage asynchronous machine in relation to the voltage endurance test" in Electrical Engineering, 105 (2023):1643-1653,
https://doi.org/10.1007/s00202-023-01767-w . .

TY  - JOUR
AU  - Aranđelović, Nemanja
AU  - Nikezić, Dušan P.
AU  - Brajović, Dragan
AU  - Ramadani, Uzahir
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10261
AB  - Recently, the idea of injecting energy with electromagnetic radiation in order to heat the plasma to achieve controlled fusion has been abandoned. This initially favored mechanism was rejected because it has been shown that after a certain temperature the plasma glows and acts as a mirror that reflects electromagnetic radiation. For that reason, today the energy is injected into the plasma by electrons. For this purpose, pulses from several electron beam generators, based on a Marx generator, are synchronously fired into the plasma. In addition to economic problems, the biggest problem of this method is the appearance of jitter, i.e., pulses with a width of about 5 ns are not simply added up but propagated in time due to the impossibility of synchronizing simultaneous triggering of the multiple electronic generators. In order to avoid this, the possibility of monitoring the pulses from an individual electron beam generator for the purpose of online synchronization is investigated in this paper. The voltage pulse monitoring of the electron beam generator was measured by instruments with the fastest response—the electro-optical Kerr effect and a fast capacitive probe. The obtained results showed that the electro-optical Kerr response is somewhat faster but much more complicated, so the use of fast capacitive probes is recommended for practice.
T2  - Fusion Science and Technology
T1  - Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe
SP  - 1
EP  - 10
DO  - 10.1080/15361055.2022.2031690
ER  - 

@article{
author = "Aranđelović, Nemanja and Nikezić, Dušan P. and Brajović, Dragan and Ramadani, Uzahir",
year = "2022",
abstract = "Recently, the idea of injecting energy with electromagnetic radiation in order to heat the plasma to achieve controlled fusion has been abandoned. This initially favored mechanism was rejected because it has been shown that after a certain temperature the plasma glows and acts as a mirror that reflects electromagnetic radiation. For that reason, today the energy is injected into the plasma by electrons. For this purpose, pulses from several electron beam generators, based on a Marx generator, are synchronously fired into the plasma. In addition to economic problems, the biggest problem of this method is the appearance of jitter, i.e., pulses with a width of about 5 ns are not simply added up but propagated in time due to the impossibility of synchronizing simultaneous triggering of the multiple electronic generators. In order to avoid this, the possibility of monitoring the pulses from an individual electron beam generator for the purpose of online synchronization is investigated in this paper. The voltage pulse monitoring of the electron beam generator was measured by instruments with the fastest response—the electro-optical Kerr effect and a fast capacitive probe. The obtained results showed that the electro-optical Kerr response is somewhat faster but much more complicated, so the use of fast capacitive probes is recommended for practice.",
journal = "Fusion Science and Technology",
title = "Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe",
pages = "1-10",
doi = "10.1080/15361055.2022.2031690"
}

Aranđelović, N., Nikezić, D. P., Brajović, D.,& Ramadani, U.. (2022). Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe. in Fusion Science and Technology, 1-10.
https://doi.org/10.1080/15361055.2022.2031690

Aranđelović N, Nikezić DP, Brajović D, Ramadani U. Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe. in Fusion Science and Technology. 2022;:1-10.
doi:10.1080/15361055.2022.2031690 .

Aranđelović, Nemanja, Nikezić, Dušan P., Brajović, Dragan, Ramadani, Uzahir, "Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe" in Fusion Science and Technology (2022):1-10,
https://doi.org/10.1080/15361055.2022.2031690 . .

TY  - JOUR
AU  - Aranđelović, Nemanja
AU  - Nikezić, Dušan P.
AU  - Brajović, Dragan
AU  - Ramadani, Uzahir
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9876
AB  - In this paper, the possibility of measuring the electronic pulse from an electronic generator for plasma heating by electro-optical method is considered. The experiments are performed by applying the Kerr effect on an electronic generator model. Kerr effect shows very good characteristics for measuring nanosecond pulse rate. However, the results obtained show that these characteristics are significantly spoiled by gamma radiation in a dynamic state as well as by the absorbed dose of gamma radiation. When the simplicity of measuring with a capacitive probe is added to that, it can be concluded that the Kerr electro-optical effect is not recommended for measurement in fusion experiments.
T2  - Radiation Effects and Defects in Solids
T1  - Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect
VL  - 176
IS  - 7-8
SP  - 747
EP  - 757
DO  - 10.1080/10420150.2021.1950153
ER  - 

@article{
author = "Aranđelović, Nemanja and Nikezić, Dušan P. and Brajović, Dragan and Ramadani, Uzahir",
year = "2021",
abstract = "In this paper, the possibility of measuring the electronic pulse from an electronic generator for plasma heating by electro-optical method is considered. The experiments are performed by applying the Kerr effect on an electronic generator model. Kerr effect shows very good characteristics for measuring nanosecond pulse rate. However, the results obtained show that these characteristics are significantly spoiled by gamma radiation in a dynamic state as well as by the absorbed dose of gamma radiation. When the simplicity of measuring with a capacitive probe is added to that, it can be concluded that the Kerr electro-optical effect is not recommended for measurement in fusion experiments.",
journal = "Radiation Effects and Defects in Solids",
title = "Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect",
volume = "176",
number = "7-8",
pages = "747-757",
doi = "10.1080/10420150.2021.1950153"
}

Aranđelović, N., Nikezić, D. P., Brajović, D.,& Ramadani, U.. (2021). Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect. in Radiation Effects and Defects in Solids, 176(7-8), 747-757.
https://doi.org/10.1080/10420150.2021.1950153

Aranđelović N, Nikezić DP, Brajović D, Ramadani U. Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect. in Radiation Effects and Defects in Solids. 2021;176(7-8):747-757.
doi:10.1080/10420150.2021.1950153 .

Aranđelović, Nemanja, Nikezić, Dušan P., Brajović, Dragan, Ramadani, Uzahir, "Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect" in Radiation Effects and Defects in Solids, 176, no. 7-8 (2021):747-757,
https://doi.org/10.1080/10420150.2021.1950153 . .

TY  - JOUR
AU  - Đekić, Saša B.
AU  - Nikezić, Dušan P.
AU  - Brajović, Dragan
AU  - Kartalović, Nenad M.
AU  - Ramadani, Uzahir
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9165
AB  - In nuclear physics experiments, it is very important to isolate the measured quantities from electromagnetic noise. Without this possibility, it is impossible to obtain usable experimental results since natural electromagnetic noise can be several orders of magnitude larger than the measured magnitude. In order to enable such measurements, it is necessary to eliminate electromagnetic noise from the experimental procedure. This is achieved by shielding against electromagnetic radiation. In this paper, experiments were performed to protect a room from electromagnetic noise. By applying all known methods of shielding against electromagnetic radiation, it was concluded that the room can be protected from the electrical component, but it is impossible to protect it from the magnetic component of electromagnetic radiation.
T2  - Nuclear Technology and Radiation Protection
T1  - Passive and active shielding against electromagnetic radiation
VL  - 35
IS  - 4
SP  - 331
EP  - 338
DO  - 10.2298/NTRP2004331D
ER  - 

@article{
author = "Đekić, Saša B. and Nikezić, Dušan P. and Brajović, Dragan and Kartalović, Nenad M. and Ramadani, Uzahir",
year = "2020",
abstract = "In nuclear physics experiments, it is very important to isolate the measured quantities from electromagnetic noise. Without this possibility, it is impossible to obtain usable experimental results since natural electromagnetic noise can be several orders of magnitude larger than the measured magnitude. In order to enable such measurements, it is necessary to eliminate electromagnetic noise from the experimental procedure. This is achieved by shielding against electromagnetic radiation. In this paper, experiments were performed to protect a room from electromagnetic noise. By applying all known methods of shielding against electromagnetic radiation, it was concluded that the room can be protected from the electrical component, but it is impossible to protect it from the magnetic component of electromagnetic radiation.",
journal = "Nuclear Technology and Radiation Protection",
title = "Passive and active shielding against electromagnetic radiation",
volume = "35",
number = "4",
pages = "331-338",
doi = "10.2298/NTRP2004331D"
}

Đekić, S. B., Nikezić, D. P., Brajović, D., Kartalović, N. M.,& Ramadani, U.. (2020). Passive and active shielding against electromagnetic radiation. in Nuclear Technology and Radiation Protection, 35(4), 331-338.
https://doi.org/10.2298/NTRP2004331D

Đekić SB, Nikezić DP, Brajović D, Kartalović NM, Ramadani U. Passive and active shielding against electromagnetic radiation. in Nuclear Technology and Radiation Protection. 2020;35(4):331-338.
doi:10.2298/NTRP2004331D .

Đekić, Saša B., Nikezić, Dušan P., Brajović, Dragan, Kartalović, Nenad M., Ramadani, Uzahir, "Passive and active shielding against electromagnetic radiation" in Nuclear Technology and Radiation Protection, 35, no. 4 (2020):331-338,
https://doi.org/10.2298/NTRP2004331D . .