Partial Discharge Localization Based on Detailed Models of Transformer and Wavelet Transform Techniques

Hassan Hosseini, Seyed Mohammad,Rezaei Baravati, Peyman The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Partial Discharge (PD) is a physical phenomenon, which causes defects and damages to the insulation. This phenomenon is regarded as the most important source of fault and defect in power transformers. Therefore, methods of high speed and precision are considered of special importance for the maintenance of transformers in localization of the origin of partial discharge. In this paper, the transformer winding is first modeled in a transient state by using RLC ladder network and multiconductor transmission line (MTL) models. The parameters of the two models were calculated by Ansoft Maxwell software, and the simulations were performed by Matlab software. Then, the PD pulses were applied to the models with different widths of pulses. With regard to the fact that the signals received after the application of PD had a variable frequency nature over time, and based on the wavelet transform and signal energy, a new method was presented for the localization of PD. Ultimately; the mentioned method was implemented on a 20 kV winding distribution transformer. Then, the performances of the models used in this paper, including RLC and MTL models, were compared in different frequency bands for the correct distinction of partial discharge location.

Comparison of High Frequency Detailed Generator Models for Partial Discharge Localization

Hassan Hosseini, S.M.,Hosseini Bafghi, S.M. The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

This paper presents partial discharge localization in stator winding of generators using multi-conductor transmission line (MTL) and RLC ladder network models. The high-voltage (HV) winding of a 6kV/250kW generator has been modeled by MATLAB software. The simulation results of the MTL and the RLC ladder network models have been evaluated with the measurements results in the frequency domain by applying of the Pearson’s correlation coefficients. Two PD generated calibrator signals in kHz and MHz frequency range were injected into different points of generator winding and the signals simulated/measured at the both ends of the winding. For partial discharge localization in stator winding of generators is necessary to calculate the frequency spectrum of the PD current signals and then estimate the poles of the system from the calculated frequency spectrum. Finally, the location of PD can be estimated. This theory applied for the above generator and the simulation/measured results show the good correlation for PD Location for RLC ladder network and MTL models in the frequency range of kHz (10kHz<f<1MHz) and MHz (1MHz<f<5MHz) respectively.

Transformer Winding Modeling based on Multi-Conductor Transmission Line Model for Partial Discharge Study

Hosseini, Seyed Mohammad Hassan,Baravati, Peyman Rezaei The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

To study and locate partial discharge(PD) and analyze the transient state of power transformer, there is a need for a high frequency model of transformer winding and calculation of its parameters. Due to the high frequency nature of partial discharge phenomenon, there is a need for an accurate model for this frequency range. To attain this goal, a Multi-Conductor Transmission Line (MTL) model is used in this paper for modeling this transformer winding. In order that the MTL model can properly simulate the transformer behavior within a frequency range it is required that its parameters be accurately calculated. In this paper, all the basic parameters of this model are calculated by the use of Finite Element Method (FEM) for a 20kV winding of a distribution transformer. The comparison of the results obtained from this model with the obtained shape of the waves by the application of PD pulse to the winding in laboratory environment shows the validity and accuracy of this model.

Transformer Winding Modeling based on Multi-Conductor Transmission Line Model for Partial Discharge Study

Seyed Mohammad Hassan Hosseini,Peyman Rezaei Baravati 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

To study and locate partial discharge(PD) and analyze the transient state of power transformer, there is a need for a high frequency model of transformer winding and calculation of its parameters. Due to the high frequency nature of partial discharge phenomenon, there is a need for an accurate model for this frequency range. To attain this goal, a Multi-Conductor Transmission Line (MTL) model is used in this paper for modeling this transformer winding. In order that the MTL model can properly simulate the transformer behavior within a frequency range it is required that its parameters be accurately calculated. In this paper, all the basic parameters of this model are calculated by the use of Finite Element Method (FEM) for a 20kV winding of a distribution transformer. The comparison of the results obtained from this model with the obtained shape of the waves by the application of PD pulse to the winding in laboratory environment shows the validity and accuracy of this model.

Partial Discharge Localization Based on Detailed Models of Transformer and Wavelet Transform Techniques

Seyed Mohammad Hassan Hosseini,Peyman Rezaei Baravati 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Partial Discharge (PD) is a physical phenomenon, which causes defects and damages to the insulation. This phenomenon is regarded as the most important source of fault and defect in power transformers. Therefore, methods of high speed and precision are considered of special importance for the maintenance of transformers in localization of the origin of partial discharge. In this paper, the transformer winding is first modeled in a transient state by using RLC ladder network and multiconductor transmission line (MTL) models. The parameters of the two models were calculated by Ansoft Maxwell software, and the simulations were performed by Matlab software. Then, the PD pulses were applied to the models with different widths of pulses. With regard to the fact that the signals received after the application of PD had a variable frequency nature over time, and based on the wavelet transform and signal energy, a new method was presented for the localization of PD. Ultimately; the mentioned method was implemented on a 20 kV winding distribution transformer. Then, the performances of the models used in this paper, including RLC and MTL models, were compared in different frequency bands for the correct distinction of partial discharge location.

Comparison of High Frequency Detailed Generator Models for Partial Discharge Localization

S. M. Hassan Hosseini,S. M. Hosseini Bafghi 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

This paper presents partial discharge localization in stator winding of generators using multi-conductor transmission line (MTL) and RLC ladder network models. The high-voltage (HV) winding of a 6kV/250kW generator has been modeled by MATLAB software. The simulation results of the MTL and the RLC ladder network models have been evaluated with the measurements results in the frequency domain by applying of the Pearson’s correlation coefficients. Two PD generated calibrator signals in kHz and MHz frequency range were injected into different points of generator winding and the signals simulated/measured at the both ends of the winding. For partial discharge localization in stator winding of generators is necessary to calculate the frequency spectrum of the PD current signals and then estimate the poles of the system from the calculated frequency spectrum. Finally, the location of PD can be estimated. This theory applied for the above generator and the simulation/measured results show the good correlation for PD Location for RLC ladder network and MTL models in the frequency range of kHz (10kHz<f<1MHz) and MHz (1MHz<f<5MHz) respectively.

Genetic diversity of Iranian wild barley (Hordeum spontaneum Koch.) populations

Hosseini Mojtaba,Yassaie Mohsen,Rashed-Mohassel Mohammad Hassan,Ghorbani Reza,Niazi Ali 한국작물학회 2022 Journal of crop science and biotechnology Vol.25 No.3

An efective weed management program requires a comprehensive knowledge of a weed’s genetic diversity. Wild barley (Hordeum spontaneum Koch) is known as an invasive weed that is rising in commercial cereal felds of Iran. Genetic diversity of 31 populations of Iranian wild barley consisting of 27 populations from Fars province along with four collected from Alborz, Kermanshah, Khuzestan, and Lorestan provinces was investigated using 15 ISSR markers. Cluster analysis showed that populations were divided into six main groups based on 88.5% similarity level. According to PCoA results, seven groups were determined based on populations’ data. The maximum similarity is recorded between Fasa and Darab populations (95.6%) and the minimum was noted between Sepidan and Mohr (78.6%). Genetic variation within the investigated wild barley populations (53%) was higher than between populations (47%). Results of Mantel test revealed a correlation between population distance and latitude, rainfall, annual temperature, and population geographic distances. Generally, latitudes, annual mean temperature, and annual mean rainfall are infuenced by genetic diversity of wild barley in Iran.

The Beneficial Effects of Olibanum on Memory Deficit Induced by Hypothyroidism in Adult Rats Tested in Morris Water Maze

Mahmoud Hosseini,Mosa Al-Reza Hadjzadeh,Mohammad Derakhshan,Shahrzad Havakhah,Fatemeh Behnam Rassouli,Hassan Rakhshandeh,Fatema Saffarzadeh 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.3

Functional consequences of hypothyroidism include impaired learning and memory and inability to produce long-term potentiation (LTP) in hippocampus. Olibanum has been used for variety of therapeutic purposes. In traditional medicine, oilbanum is used to enhance learning and memory. In the present study the effect of olibanum on memory deficit in hypothyroid rats was investigated. Male wistar rats were divided into four groups and treated for 180 days. Group 1 received tap drinking water while in group 2, 0.03% methimazol was added to drinking water. Group 3 and 4 were treated with 0.03% methimazole as well as 100 and 500 mg/kg olibanum respectively. The animals were tested in Morris water maze. The swimming speed was significantly lower and the distance and time latency were higher in group 2 compared with group 1. In groups 3 and 4 the swimming speed was significantly higher while, the length of the swim path and time latency were significantly lower in comparison with group 2. It is concluded that methimazole-induced hypothyroidism impairs learning and memory in adult rats which could be prevented by using olibanum.

Exploring the role of place on COVID-19 spatial distribution in 22 districts of Tehran, Iran

Dastjerdi Hassan Kamran,Nasrabadi Narjessadat Hosseini 대한공간정보학회 2021 Spatial Information Research Vol.29 No.6

Our purpose in this paper is to emphasize the theory of ‘‘the effect of the role of place on the spatial distribution of phenomena’’, whether problems or opportunities. In almost a year, COVID-19 has disrupted people’s lives in Iran and caused minor to large damages in various aspects of citizens’ lives. The outbreak of the disease in the metropolis of Tehran, given that it is the capital of Iran, is however more worrying than other cities in Iran. Therefore, the importance of this research is that it tries to provide hypotheses that explain the reason for the increase in the incidence of the disease by emphasizing the role of place in some districts of Tehran and by statistical analysis and preparing a questionnaire and questions from the elite and Executive experts and citizens in different districts of Tehran have been trained. The results showed that there was a direct positive correlation between the role of place (economic, cultural, political and environmental) in the 22 districts of Tehran and the increased population and increased number of coronavirus-infected people. According to the evaluation of the performance (role) of each district in Tehran, districts 11, 12, 17 and 20 had the most economic places (bazaar and mall), as a result the number of coronavirus-infected people was higher in these districts. The political places are in the next place. The districts where most political places were located were 8 and 11. Areas with service and cultural places such as passenger terminals, subway stations, universities and hospitals were the last in exposing to this virus.

Glutathione-responsive hydrogel and molecularly imprinted polymer nanospheres: New aspect on cisplatin delivery

Mohammad Hassan Loghmani,Abdollah Fallah Shojaie,Seyyedeh Azadeh Hosseini 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.96 No.-

In this study, Glutathione-responsive hydrogel, MIPs and their related NIPs were synthesized byprecipitation polymerization method. Effect of HEMA/MAA and EGDMA/TRIM as functional monomerand crosslinking agents on size, morphology, drug loading and releasing were studied. BACy as a disulfidecross-linking agent was used in praparation of Glutathione-responsive hydrogel. The size andmorphology of MIPs and NIPs were examined by FE-SEM technique. Results showed EGDMAsynthesizedMIPs had the smaller size than TRIM-prepared MIPs. In order to measure the capacity of MIPsor NIPs for binding to cisplatin, static and dynamic adsorption experiments were done. The amounts ofcisplatin were measured by HPLC method. The binding capacity of drug by MIPs is observed to be higherthan NIPs. The EGDMA-synthesized polymers showed a high percentage of adsorption. NIPs weresaturated much sooner than MIPs. In vitro release assays of cisplatin were done in PBS at pH = 7.4 andtemperature of 37 C. The results showed that increase of the amount of GSH cause to increase release ofthe drug from hydrogel.