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Turn to turn fault is one of the major internal failures in the power transformers that if it is ... more Turn to turn fault is one of the major internal failures in the power transformers that if it is not quickly detected, can be extended and led to a complete transformer breakdown. So, the diagnosis and location of the turn to turn fault of the power transformer, as one of the most important equipment in the power system, is the main objective of this paper. For this purpose, a detailed model of a three-phase transformer is presented by the finite element method (FEM) to investigate this fault in the different situations. Accordingly, the number of short-circuit turns as well as fault location, cause to generate the high forces between the short-circuit turns and the other healthy winding turns. Consequently, in this paper an appropriate method based on force analysis of winding turns for detecting, locating and determining fault severity is introduced. Keyword: Turn to turn fault, Recognition, location, imposed forces, FEM.
International Transactions on Electrical Energy Systems, 2019
In this paper, by using of the magnetic equivalent circuit method, an accurate model of a switche... more In this paper, by using of the magnetic equivalent circuit method, an accurate model of a switched reluctance motor with respect to the traditional modeling is presented. This modeling is perfectly considered the magnetic saturation effects of iron core and space harmonic distribution of stator and rotor poles. The presented magnetic equivalent circuit model evaluated the motor performance in different situations with low time consumption properly. This method has less complexity for dynamic modeling of switched reluctance motor. Also, this modeling can be used for optimal designing of motor performance in various applications with high accuracy and precision. In this paper, the various sequence of phases excitations with different overlap between two adjacent phases voltages are evaluated to choose the appropriate excitation. Finally, the proposed magnetic equivalent method results are validated by comparing the corresponding finite element analysis. The simulations results confirmed the usefulness of the proposed model.
International Transactions on Electrical Energy Systems, 2018
Mathematical and Computer Modelling of Dynamical Systems, 2012
This article presents a new generalized non-linear dynamical model of a transformer with saturati... more This article presents a new generalized non-linear dynamical model of a transformer with saturation and hysteresis effects. The structure of this new model is based on a magnetic equivalent circuit with non-linear reluctance elements. Using this method, accurate models of three- and five-legged transformers with magnetic saturation and hysteresis phenomena of iron core are introduced and inrush current in normal and sequential phase energization techniques are evaluated. Moreover, the effects of neutral resistance, magnetic structure and winding connections on inrush current are determined. In addition, for validation of the proposed model, some numerical simulations are made and compared with other techniques. Simulation results illustrate that the proposed model has high accuracy and efficiency for non-linear dynamical modelling of a transformer.
Turn to turn fault is one of the major internal failures in the power transformers that if it is ... more Turn to turn fault is one of the major internal failures in the power transformers that if it is not quickly detected, can be extended and led to a complete transformer breakdown. So, the diagnosis and location of the turn to turn fault of the power transformer, as one of the most important equipment in the power system, is the main objective of this paper. For this purpose, a detailed model of a three-phase transformer is presented by the finite element method (FEM) to investigate this fault in the different situations. Accordingly, the number of short-circuit turns as well as fault location, cause to generate the high forces between the short-circuit turns and the other healthy winding turns. Consequently, in this paper an appropriate method based on force analysis of winding turns for detecting, locating and determining fault severity is introduced. Keyword: Turn to turn fault, Recognition, location, imposed forces, FEM.
International Transactions on Electrical Energy Systems, 2019
In this paper, by using of the magnetic equivalent circuit method, an accurate model of a switche... more In this paper, by using of the magnetic equivalent circuit method, an accurate model of a switched reluctance motor with respect to the traditional modeling is presented. This modeling is perfectly considered the magnetic saturation effects of iron core and space harmonic distribution of stator and rotor poles. The presented magnetic equivalent circuit model evaluated the motor performance in different situations with low time consumption properly. This method has less complexity for dynamic modeling of switched reluctance motor. Also, this modeling can be used for optimal designing of motor performance in various applications with high accuracy and precision. In this paper, the various sequence of phases excitations with different overlap between two adjacent phases voltages are evaluated to choose the appropriate excitation. Finally, the proposed magnetic equivalent method results are validated by comparing the corresponding finite element analysis. The simulations results confirmed the usefulness of the proposed model.
International Transactions on Electrical Energy Systems, 2018
Mathematical and Computer Modelling of Dynamical Systems, 2012
This article presents a new generalized non-linear dynamical model of a transformer with saturati... more This article presents a new generalized non-linear dynamical model of a transformer with saturation and hysteresis effects. The structure of this new model is based on a magnetic equivalent circuit with non-linear reluctance elements. Using this method, accurate models of three- and five-legged transformers with magnetic saturation and hysteresis phenomena of iron core are introduced and inrush current in normal and sequential phase energization techniques are evaluated. Moreover, the effects of neutral resistance, magnetic structure and winding connections on inrush current are determined. In addition, for validation of the proposed model, some numerical simulations are made and compared with other techniques. Simulation results illustrate that the proposed model has high accuracy and efficiency for non-linear dynamical modelling of a transformer.