2017 6th International Conference on Computer Applications In Electrical Engineering-Recent Advances (CERA), 2017
To maintain the reliability of power supply, proper functioning of all equipment is necessary. Th... more To maintain the reliability of power supply, proper functioning of all equipment is necessary. The distribution transformers constitute a major part of a distribution system and its remaining life should be properly investigated. Renewable energy sources are integrated into a distribution system to reduce losses, improving voltage profile and save energy cost. This may affect the life of equipment present in the existing system. In this paper, a practical distribution system with installed rooftop solar photo-voltaic (PV) units is considered for investigation. Total study periods has been divided into three parts. The benefits of PV in terms of the life of the transformers have been quantified for the each part. For PV integration and time-series load flow simulation, MATLAB component objective model (COM) interface of OpenDSS is used. The actual load, load shape, temperature and irradiation data have been collected to prepare input to the simulation model. The results show that the...
2016 IEEE Power and Energy Society General Meeting (PESGM), 2016
This paper presents an algorithm to precisely detect the saturation of Current Transformers (CTs)... more This paper presents an algorithm to precisely detect the saturation of Current Transformers (CTs). The algorithm is based on first difference of magnitudes of Lissajous Curve. These Lissajous curves are generated using secondary current signal and its first derivative. PSCAD was used to generate secondary current signals for various practical cases of fault currents and MATLAB was used to implement the proposed algorithm. The algorithm is tested for various cases of severe and mild CT saturation. Moreover, the effects of various factors, such as remnant magnetic flux density, noise and burden power factor are studied. Test results reflect that the proposed algorithm efficiently detect the start and end instants of CT Saturation for almost all cases.
2017 3rd International Conference on Condition Assessment Techniques in Electrical Systems (CATCON), 2017
In recent years, a lot of advancement took place in distributed generation (DG) and electric vehi... more In recent years, a lot of advancement took place in distributed generation (DG) and electric vehicle (EV) technology. As a result, many utilities worldwide are planning to deploy DG in their distribution system to ease the growing energy demand. Moreover, many countries are encouraging the growth of EVs to reduce carbon and other green house gas emission, limit air and noise pollution, and enhance energy security. However, in the design of traditional power systems, these technological advancements were not considered. These technologies can make an impact on the life of assets of the distribution systems. Therefore, they need to be addressed appropriately for better estimation of asset utilization. A DT is one of the major assets for any electrical distribution system. For satisfactory operation, its performance in the presence of new emerging technology should be properly investigated. This paper has reviewed the impact of these technologies on the aging along with some measure to minimize loss-of-life.
In the literature, many works detail the benefits of Volt-VAr control to minimise the losses in a... more In the literature, many works detail the benefits of Volt-VAr control to minimise the losses in a distribution system. However, it is also important to understand the impact of it on the life of the other assets in a distribution system. Since, distribution transformers (DTs) are the important assets of a distribution system, the main objective of this paper is to appraise the impact of Volt-VAr control on the life of DTs. The paper presents a detailed methodology to estimate the loss of life (LoL) of the DTs under various Volt-VAr control schemes, such as base-case (without any control), voltage control, and Volt-VAr control (VVC). The proposed methodology is implemented on modified IEEE 13-bus and IIT-Roorkee distribution systems considering the voltage-dependent load models, seasonal load influences, and harmonics. The simulation results are presented to explore the ability of VVC in reducing the hottest-spot temperature in the DTs during peak hours. The results reveal that the life of the DT can be extended by a considerable amount by optimally controlling the voltages and reactive power flows in the distribution system. Moreover, it gives a significant reduction in energy losses and improvement in power factor in distribution systems.
Abstract The study of the impact of load models on transformer insulation life is essential for t... more Abstract The study of the impact of load models on transformer insulation life is essential for the truthful aging calculation. In most of the studies related to the assessment of transformer aging, distribution loads are treated as constant power type. However, the practical loads are of mix type (combination of constant power, constant current, constant impedance). Moreover, the residential, commercial, and industrial loads comprise the different percentages of constant power, constant current, and constant impedance loads. In this article, different load models are investigated to quantify their impact on the aging calculation of a transformer under various loading scenarios and environmental conditions. The study includes different classes of the loads with corresponding load shapes, ambient temperatures, determined for a typical week of each season. It considers highly unbalanced transformer loading conditions and network configurations. The study also considers the effect of harmonics on the transformer aging. Aging acceleration rate and percentage loss of life of the substation transformer connected to IEEE 13-bus system have been calculated for different loading and climatic conditions. The same procedure has been adopted for the modified IEEE 123-bus system, and the trends of the results have been compared with the IEEE 13-bus system. It has been shown that the load models make a considerable effect on life calculation of a transformer. Therefore, selection of an appropriate load model is important for accurate estimation of aging of a transformer.
a b s t r a c t CO 2 sequestration by cyanobacteria and green algae are receiving increased atten... more a b s t r a c t CO 2 sequestration by cyanobacteria and green algae are receiving increased attention in alleviating the impact of increasing CO 2 in the atmosphere. They, in addition to CO 2 capture, can produce renewable energy carriers such as carbon free energy hydrogen, bioethanol, biodiesel and other valuable biomolecules. Biological fixation of CO 2 are greatly affected by the characteristics of the microbial strains, their tolerance to temperature and the CO 2 present in the flue gas including SO X , NO X . However, there are additional factors like the availability of light, pH, O 2 removal, suitable design of the photobioreactor, culture density and the proper agitation of the reactor that will affect significantly the CO 2 sequestration process. Present paper deals with the photobioreactors of different geometry available for biomass production. It also focuses on the hybrid types of reactors (integrating two reactors) which can be used for overcoming the bottlenecks of a single photobioreactor.
2017 6th International Conference on Computer Applications In Electrical Engineering-Recent Advances (CERA), 2017
To maintain the reliability of power supply, proper functioning of all equipment is necessary. Th... more To maintain the reliability of power supply, proper functioning of all equipment is necessary. The distribution transformers constitute a major part of a distribution system and its remaining life should be properly investigated. Renewable energy sources are integrated into a distribution system to reduce losses, improving voltage profile and save energy cost. This may affect the life of equipment present in the existing system. In this paper, a practical distribution system with installed rooftop solar photo-voltaic (PV) units is considered for investigation. Total study periods has been divided into three parts. The benefits of PV in terms of the life of the transformers have been quantified for the each part. For PV integration and time-series load flow simulation, MATLAB component objective model (COM) interface of OpenDSS is used. The actual load, load shape, temperature and irradiation data have been collected to prepare input to the simulation model. The results show that the...
2016 IEEE Power and Energy Society General Meeting (PESGM), 2016
This paper presents an algorithm to precisely detect the saturation of Current Transformers (CTs)... more This paper presents an algorithm to precisely detect the saturation of Current Transformers (CTs). The algorithm is based on first difference of magnitudes of Lissajous Curve. These Lissajous curves are generated using secondary current signal and its first derivative. PSCAD was used to generate secondary current signals for various practical cases of fault currents and MATLAB was used to implement the proposed algorithm. The algorithm is tested for various cases of severe and mild CT saturation. Moreover, the effects of various factors, such as remnant magnetic flux density, noise and burden power factor are studied. Test results reflect that the proposed algorithm efficiently detect the start and end instants of CT Saturation for almost all cases.
2017 3rd International Conference on Condition Assessment Techniques in Electrical Systems (CATCON), 2017
In recent years, a lot of advancement took place in distributed generation (DG) and electric vehi... more In recent years, a lot of advancement took place in distributed generation (DG) and electric vehicle (EV) technology. As a result, many utilities worldwide are planning to deploy DG in their distribution system to ease the growing energy demand. Moreover, many countries are encouraging the growth of EVs to reduce carbon and other green house gas emission, limit air and noise pollution, and enhance energy security. However, in the design of traditional power systems, these technological advancements were not considered. These technologies can make an impact on the life of assets of the distribution systems. Therefore, they need to be addressed appropriately for better estimation of asset utilization. A DT is one of the major assets for any electrical distribution system. For satisfactory operation, its performance in the presence of new emerging technology should be properly investigated. This paper has reviewed the impact of these technologies on the aging along with some measure to minimize loss-of-life.
In the literature, many works detail the benefits of Volt-VAr control to minimise the losses in a... more In the literature, many works detail the benefits of Volt-VAr control to minimise the losses in a distribution system. However, it is also important to understand the impact of it on the life of the other assets in a distribution system. Since, distribution transformers (DTs) are the important assets of a distribution system, the main objective of this paper is to appraise the impact of Volt-VAr control on the life of DTs. The paper presents a detailed methodology to estimate the loss of life (LoL) of the DTs under various Volt-VAr control schemes, such as base-case (without any control), voltage control, and Volt-VAr control (VVC). The proposed methodology is implemented on modified IEEE 13-bus and IIT-Roorkee distribution systems considering the voltage-dependent load models, seasonal load influences, and harmonics. The simulation results are presented to explore the ability of VVC in reducing the hottest-spot temperature in the DTs during peak hours. The results reveal that the life of the DT can be extended by a considerable amount by optimally controlling the voltages and reactive power flows in the distribution system. Moreover, it gives a significant reduction in energy losses and improvement in power factor in distribution systems.
Abstract The study of the impact of load models on transformer insulation life is essential for t... more Abstract The study of the impact of load models on transformer insulation life is essential for the truthful aging calculation. In most of the studies related to the assessment of transformer aging, distribution loads are treated as constant power type. However, the practical loads are of mix type (combination of constant power, constant current, constant impedance). Moreover, the residential, commercial, and industrial loads comprise the different percentages of constant power, constant current, and constant impedance loads. In this article, different load models are investigated to quantify their impact on the aging calculation of a transformer under various loading scenarios and environmental conditions. The study includes different classes of the loads with corresponding load shapes, ambient temperatures, determined for a typical week of each season. It considers highly unbalanced transformer loading conditions and network configurations. The study also considers the effect of harmonics on the transformer aging. Aging acceleration rate and percentage loss of life of the substation transformer connected to IEEE 13-bus system have been calculated for different loading and climatic conditions. The same procedure has been adopted for the modified IEEE 123-bus system, and the trends of the results have been compared with the IEEE 13-bus system. It has been shown that the load models make a considerable effect on life calculation of a transformer. Therefore, selection of an appropriate load model is important for accurate estimation of aging of a transformer.
a b s t r a c t CO 2 sequestration by cyanobacteria and green algae are receiving increased atten... more a b s t r a c t CO 2 sequestration by cyanobacteria and green algae are receiving increased attention in alleviating the impact of increasing CO 2 in the atmosphere. They, in addition to CO 2 capture, can produce renewable energy carriers such as carbon free energy hydrogen, bioethanol, biodiesel and other valuable biomolecules. Biological fixation of CO 2 are greatly affected by the characteristics of the microbial strains, their tolerance to temperature and the CO 2 present in the flue gas including SO X , NO X . However, there are additional factors like the availability of light, pH, O 2 removal, suitable design of the photobioreactor, culture density and the proper agitation of the reactor that will affect significantly the CO 2 sequestration process. Present paper deals with the photobioreactors of different geometry available for biomass production. It also focuses on the hybrid types of reactors (integrating two reactors) which can be used for overcoming the bottlenecks of a single photobioreactor.
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Papers by Kanhaiya Kumar