IEEE Transactions on Applied Superconductivity, 2011
Abstract Among superconducting fault-current limiters (FCLs), the inductive type has some distinc... more Abstract Among superconducting fault-current limiters (FCLs), the inductive type has some distinctive merits such as large design flexibility due to the turn ratio, isolation between a current-limiting device and a power transmission line, and low heat losses. This paper ...
2017 IEEE 4th International Conference on Knowledge-Based Engineering and Innovation (KBEI)
A saturated core fault current limiter (SCFCL) is an important instrument in limitation of increa... more A saturated core fault current limiter (SCFCL) is an important instrument in limitation of increasing fault current in power systems. The core of this type of limiters in normal operating condition is in the saturated state and when a fault occurs, transfers to the desaturated state. In this paper, different structures of the saturated core limiters with various AC and DC winding arrangements, and using superconductor tapes and magnet to saturate the core is presented, and currents flow through limiters in the normal and fault condition of the system is evaluated by Finite Element (FE) simulation softwares. Also, the flux density in different parts of the core for various arrangement are investigated, and desired analysis is carried out on them.
International Journal of Electrical Power & Energy Systems, 2021
Nowadays, the application of non-linear loads such as, rectifiers, electronic phase control, PWM ... more Nowadays, the application of non-linear loads such as, rectifiers, electronic phase control, PWM drives, gives rise to a vastly increased level of harmonics in the power network. As such, the transport currents of transformers are non-sinusoidal alternating currents. On the other hand, AC losses are one of the most critical characteristics for the design and operation of high-temperature superconducting (HTS) transformers. The amount of hysteresis losses is a key parameter for the design of HTS windings affecting equipment, cooling cost, efficiency, and transformer economic feasibility. The computation of AC losses by traditional techniques, is suitable for the sinusoidal current condition. While, non-linear loads brings about different number of peaks and amplitudes in the current waveform passing through the HTS transformer windings. So that, in addition to the major hysteresis loop, a number of minor hysteresis loops are also formed changing the hysterical nature of the AC losses...
The higher frequency transient signals generated as a result of a power system fault or disturban... more The higher frequency transient signals generated as a result of a power system fault or disturbance provide the basis for an alternative approach to power system containing connectors and cables result in unsuitable operation of the system. However one major challenge is the need to ensure that the transients to be neutralized by electromagnetic compatibility (EMC) issues and cabling routes. This paper proposes novel method for optimal cable routings and connectors; a combinatorial design Algorithm, to choose the best path when two or more physical paths are available. The best path from EMC point of view can be chosen based upon various criteria such as monetary cost minimization, voltage drop and quality (electromagnetic compatibility) parameters. This paper initially provides a numerical 2D and 3D resolution of the problems of radiation generated by current sources. The approach is based on the finite element method (FEM) associated with absorbing boundary conditions. The present...
Given the unique electrical and magnetic properties of superconductors, high temperature supercon... more Given the unique electrical and magnetic properties of superconductors, high temperature superconducting (HTS) transformers will play a central role in the electricity industry in the future. Therefore, identification and analysis of this type of transformers seems necessary and indispensable. To date, many types of development plans for HTS transformers have been carried out by major power companies and important research institutes, and it is expected that this type of transformers will become one of the superconducting power equipments installed at the first stage of commercialization in the power system. However, a review of reports and papers published in this field shows that there is still much work to be done to improve the design and performance of these transformers. This article presented a review classified by subject of previous research to help orient future research into the design, analysis, and manufacturing of this type of transformers.
Introducing high-temperature superconductors (HTS) and their outstanding properties stimulates sc... more Introducing high-temperature superconductors (HTS) and their outstanding properties stimulates scientists and engineers in various fields to modernise the products with this new technology. Electric power industry also was affected by this finding in different branches including bearings. The idea of HTS bearings was rapidly developed due to its two main features, i.e. self-stability and contactless operation which leads to save remarkable amount of energy. However, a successful implementation of HTS bearing undoubtedly requires an accurate modelling in the beginning. The contribution of this study is an analytical method for simulating the electromagnetic behaviour of a radial HTS magnetic bearing. The governing non-linear system of partial differential equations in the HTS bulks deduced from the H-formulation along with the E–J power law and is efficiently solved using variational iteration method (VIM). The validity of VIM is ascertained by comparing the results with numerical two-dimensional axisymmetric finite-element method simulations.
... Vehicles and the UTS Plug in Нybrid Electric Vehicle Salisa Abdul Rahman, Nong Zhang ... Powe... more ... Vehicles and the UTS Plug in Нybrid Electric Vehicle Salisa Abdul Rahman, Nong Zhang ... Power Generation Sector of Pakistan Muhammad Khyzer Bin Dost and Muhammad Asim Khan ... Transmission Line Analysis Using Eхact, Nominal П, And Modified П Models Haitham Safar ...
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
Purpose Permanent magnet passive magnetic bearings (PMBs) are used for suspension of rotating sha... more Purpose Permanent magnet passive magnetic bearings (PMBs) are used for suspension of rotating shafts in one direction. PMBs with alternating radially magnetized rings having back iron is one of the most optimum configurations among all configurations of PMBs. This paper aims to investigate the effect of the conductivity and permeability of these back irons on the stiffness and damping of the configuration. Design/methodology/approach The stiffness and damping of the configuration will be calculated through a 2D dynamic analytical method and validated by FEM simulations. Findings The results of the paper show how the permeability and conductivity of the back irons can affect stiffness and damping of PMB. Furthermore, the size of the magnets and the air intervals between them are optimized for maximum stiffness and damping. Originality/value The results show that these bearings can have some intrinsic damping without any loss of stiffness, which can be useful for many applications.
Since Current Injection Transformers (CIT) are within the major group of the standard type test e... more Since Current Injection Transformers (CIT) are within the major group of the standard type test equipments in electrical industry, their performances are very crucial. CIT is widely used for standard tests in electrical industry for a variety of purposes, such as relay protection systems consisting of insolated HV conductor, fuses, SF6 switches, low voltage switches (ACB, and MCCB), sectionalizing switches,
IEEE Transactions on Applied Superconductivity, 2011
Abstract Among superconducting fault-current limiters (FCLs), the inductive type has some distinc... more Abstract Among superconducting fault-current limiters (FCLs), the inductive type has some distinctive merits such as large design flexibility due to the turn ratio, isolation between a current-limiting device and a power transmission line, and low heat losses. This paper ...
2017 IEEE 4th International Conference on Knowledge-Based Engineering and Innovation (KBEI)
A saturated core fault current limiter (SCFCL) is an important instrument in limitation of increa... more A saturated core fault current limiter (SCFCL) is an important instrument in limitation of increasing fault current in power systems. The core of this type of limiters in normal operating condition is in the saturated state and when a fault occurs, transfers to the desaturated state. In this paper, different structures of the saturated core limiters with various AC and DC winding arrangements, and using superconductor tapes and magnet to saturate the core is presented, and currents flow through limiters in the normal and fault condition of the system is evaluated by Finite Element (FE) simulation softwares. Also, the flux density in different parts of the core for various arrangement are investigated, and desired analysis is carried out on them.
International Journal of Electrical Power & Energy Systems, 2021
Nowadays, the application of non-linear loads such as, rectifiers, electronic phase control, PWM ... more Nowadays, the application of non-linear loads such as, rectifiers, electronic phase control, PWM drives, gives rise to a vastly increased level of harmonics in the power network. As such, the transport currents of transformers are non-sinusoidal alternating currents. On the other hand, AC losses are one of the most critical characteristics for the design and operation of high-temperature superconducting (HTS) transformers. The amount of hysteresis losses is a key parameter for the design of HTS windings affecting equipment, cooling cost, efficiency, and transformer economic feasibility. The computation of AC losses by traditional techniques, is suitable for the sinusoidal current condition. While, non-linear loads brings about different number of peaks and amplitudes in the current waveform passing through the HTS transformer windings. So that, in addition to the major hysteresis loop, a number of minor hysteresis loops are also formed changing the hysterical nature of the AC losses...
The higher frequency transient signals generated as a result of a power system fault or disturban... more The higher frequency transient signals generated as a result of a power system fault or disturbance provide the basis for an alternative approach to power system containing connectors and cables result in unsuitable operation of the system. However one major challenge is the need to ensure that the transients to be neutralized by electromagnetic compatibility (EMC) issues and cabling routes. This paper proposes novel method for optimal cable routings and connectors; a combinatorial design Algorithm, to choose the best path when two or more physical paths are available. The best path from EMC point of view can be chosen based upon various criteria such as monetary cost minimization, voltage drop and quality (electromagnetic compatibility) parameters. This paper initially provides a numerical 2D and 3D resolution of the problems of radiation generated by current sources. The approach is based on the finite element method (FEM) associated with absorbing boundary conditions. The present...
Given the unique electrical and magnetic properties of superconductors, high temperature supercon... more Given the unique electrical and magnetic properties of superconductors, high temperature superconducting (HTS) transformers will play a central role in the electricity industry in the future. Therefore, identification and analysis of this type of transformers seems necessary and indispensable. To date, many types of development plans for HTS transformers have been carried out by major power companies and important research institutes, and it is expected that this type of transformers will become one of the superconducting power equipments installed at the first stage of commercialization in the power system. However, a review of reports and papers published in this field shows that there is still much work to be done to improve the design and performance of these transformers. This article presented a review classified by subject of previous research to help orient future research into the design, analysis, and manufacturing of this type of transformers.
Introducing high-temperature superconductors (HTS) and their outstanding properties stimulates sc... more Introducing high-temperature superconductors (HTS) and their outstanding properties stimulates scientists and engineers in various fields to modernise the products with this new technology. Electric power industry also was affected by this finding in different branches including bearings. The idea of HTS bearings was rapidly developed due to its two main features, i.e. self-stability and contactless operation which leads to save remarkable amount of energy. However, a successful implementation of HTS bearing undoubtedly requires an accurate modelling in the beginning. The contribution of this study is an analytical method for simulating the electromagnetic behaviour of a radial HTS magnetic bearing. The governing non-linear system of partial differential equations in the HTS bulks deduced from the H-formulation along with the E–J power law and is efficiently solved using variational iteration method (VIM). The validity of VIM is ascertained by comparing the results with numerical two-dimensional axisymmetric finite-element method simulations.
... Vehicles and the UTS Plug in Нybrid Electric Vehicle Salisa Abdul Rahman, Nong Zhang ... Powe... more ... Vehicles and the UTS Plug in Нybrid Electric Vehicle Salisa Abdul Rahman, Nong Zhang ... Power Generation Sector of Pakistan Muhammad Khyzer Bin Dost and Muhammad Asim Khan ... Transmission Line Analysis Using Eхact, Nominal П, And Modified П Models Haitham Safar ...
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
Purpose Permanent magnet passive magnetic bearings (PMBs) are used for suspension of rotating sha... more Purpose Permanent magnet passive magnetic bearings (PMBs) are used for suspension of rotating shafts in one direction. PMBs with alternating radially magnetized rings having back iron is one of the most optimum configurations among all configurations of PMBs. This paper aims to investigate the effect of the conductivity and permeability of these back irons on the stiffness and damping of the configuration. Design/methodology/approach The stiffness and damping of the configuration will be calculated through a 2D dynamic analytical method and validated by FEM simulations. Findings The results of the paper show how the permeability and conductivity of the back irons can affect stiffness and damping of PMB. Furthermore, the size of the magnets and the air intervals between them are optimized for maximum stiffness and damping. Originality/value The results show that these bearings can have some intrinsic damping without any loss of stiffness, which can be useful for many applications.
Since Current Injection Transformers (CIT) are within the major group of the standard type test e... more Since Current Injection Transformers (CIT) are within the major group of the standard type test equipments in electrical industry, their performances are very crucial. CIT is widely used for standard tests in electrical industry for a variety of purposes, such as relay protection systems consisting of insolated HV conductor, fuses, SF6 switches, low voltage switches (ACB, and MCCB), sectionalizing switches,
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