2019 8th International Conference on Modern Power Systems (MPS)
This paper uses analytical, numerical and experimental procedures for investigating several effec... more This paper uses analytical, numerical and experimental procedures for investigating several effects of the unbalanced voltage supply on the motor performance. The analytical electrical model of the induction motor (IM), developed for positive and negative sequence is an appropriate instrument for the evaluation of the IM operation in conditions of unbalanced power supply. This model brings a coherent procedure for the calculating the unbalanced current, losses of each category, respectively the developed torque. Data from analytical calculations became input for numerical analysis of the motor using the Finite Element Method (FEM). The induction motor performance evaluation through experiments is meant to compare the predicted results and complete the investigation. Finally, the work comes with recommendations regarding the eventual rerating as well as protective equipment set-up.
2019 Electric Vehicles International Conference (EV)
This paper presents an inductive coupling system used to recharge the batteries of electric vehic... more This paper presents an inductive coupling system used to recharge the batteries of electric vehicles (EV) as well as the ultra-capacitors used as energy storage elements wirelessly. Although ultra-capacitors can quickly charge, the standard inductive coupled circuits provide maximum power only for specific load impedance. The value of this impedance depends on the geometrical dimensions of the coils, coils configuration, as well as the distance between them. Since an ultra-capacitor in the charging mode is equivalent to an instantaneously increasing impedance, the maximum power supplied to the ultra-capacitor involves a single point inside the charging range, resulting in better optimum charging time. The analysis of the inductive coupling theory reveals that the optimal load impedance can vary by adjusting the secondary coil inductance and the resonant tuning capacitance. The proposal to modify the optimal load impedance dynamically throughout the capacitor charging range consists of a three-tapped secondary coil. Furthermore, this paper aims to design and analyze optimal wireless battery loading systems for electronic devices. The construction of these optimal systems uses an inductive coupling architecture that has a multi-tapped secondary coil (receiver). In this case, there are multiple magnetic couplings between the emitting coil and the receiving coils and even between the receiving coils corresponding to each tap. Consequently, results in a dynamic change of the coils geometries to modify the optimum load impedance and maximize the active power transmitted to the load. A thorough comparison involving performances put face to face the wireless power transfer systems (WPTS) containing only two magnetically coupled coils with those with multi-tapped secondary coils (MTSC). The main conclusion reveals the advantages of inductive architecture with MTSC.
2017 International Conference on Modern Power Systems (MPS), 2017
Switched networks modelling lead very often to discontinuities of circuit's variables corresp... more Switched networks modelling lead very often to discontinuities of circuit's variables corresponding to switching time moments. This phenomenon is said to have inconsistent initial conditions (IIC). The IIC problem appears only for ideal switches in ideal circuits when, after switching, the circuit contains excess elements. As a consequence, Dirac delta functions and their derivatives can occur in the circuit's variables variations which are proportional with the discontinuous variables derivatives. This paper presents a very precise method for analyzing the dynamic circuits with IIC, method which has the advantage given by its simplicity. This approach is based on modified nodal method, modelling the ideal switches using time variable resistors. The described algorithm has been implemented in the general program for real switched networks rapid analysis.
2018 International Conference on Applied and Theoretical Electricity (ICATE), 2018
This paper presents a method of modeling the synchronous machine subjected to transient regimes. ... more This paper presents a method of modeling the synchronous machine subjected to transient regimes. Then, the obtained model is utilized to simulate the dynamic behavior of the high power synchronous generator in conditions of asynchronous operation and for sudden three-phase short circuit occurred at the stator winding terminals. The model is based on Park-Blondel equations expressed in canonical form. The equations are built considering the influence of the induced current into the massive rotor of the generator and the nonlinearity of the magnetization characteristic. For the fulfillment of the simulated cases, an implicit Gear algorithm of third order is applied for the integration of the equations. The results obtained through simulations performed using the proposed model, are compared to those obtained running the predefined model offered for the synchronous machine by Simulink package from MATLAB. In both cases identical simulation scenarios are considered.
2019 15th International Conference on Engineering of Modern Electric Systems (EMES), 2019
The subject of this paper is a practical example where the application of the scattering paramete... more The subject of this paper is a practical example where the application of the scattering parameters (SP) results in the active power transfer efficiency increase. The process of information transmission (propagation) improves, also. The efficiency assessment addresses the transfer function of a two-port network. The computation of the maximum power transferred to the load requires the application of the maximum active power transfer theorem. Furthermore, the results obtained applying the electric circuit theory are compared to those obtained through the S parameters method. Moreover, utilizing the SP is possible to determine the characteristic parameters of analog filters. In this way it is possible to compute the stop and pass frequency bands and classify the nature of the filters. In the domains of high and very high frequencies, SP can be easily measured using a Vector Network Analyzer (VNA). The SP offers an attractive procedure to solve linear circuits operating in the sinusoidal regime, with direct reference to multi-poles. Finally, simulation results regarding all of the above mentioned parameters have been compared with data obtained either experimentally or from literature.
2017 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) & 2017 Intl Aegean Conference on Electrical Machines and Power Electronics (ACEMP), 2017
The wireless power transfer systems (WPTS) work at frequencies between 20 kHz – 40 MHz. Consideri... more The wireless power transfer systems (WPTS) work at frequencies between 20 kHz – 40 MHz. Considering the system consisting of two magnetically coupled coils, used in WPTSs, as a passive linear two-port network (PL2PN) in harmonic state, this paper describes the possibility of using the scattering parameters S in generating the power gains between the two ports of these coils. The amplification (or attenuation) property of the PL2PN can be emphasised by comparing the active Pin - the power given by the PL2PN at its input, with PL - the active power transmitted to the load. By computing the most significant gains, we describe, in this paper, the practical use of S parameters in order to make more efficient the information propagation and transmission processes in the wireless electromagnetic energy transmission from the emitter to the receiver coils for WPTS. Starting from the correct formulation of S parameters, their generation takes place in an automatic manner, based on the corresp...
2019 International Conference on Electromechanical and Energy Systems (SIELMEN), 2019
The efficient utilization of the magnetostrictive elongation is a critical factor in achieving th... more The efficient utilization of the magnetostrictive elongation is a critical factor in achieving the highly performant operation of the magnetostrictive motors. There are two main conditions to be fulfilled for the magnetostrictive motor to be optimally designed. The first one requires a unique value for the permanent magnet field intensity and the intensity of the magnetic field at the half of the linear segment of the magnetostrictive characteristic. The second condition requires that the permanent magnet recoil line must stay the same. This paper presents an experimental method applied to a proposed prototype, intended for testing the magnetostrictive motors in operation. The utilization of mechanical characteristics determined the load setup for achieving meaningful data. The Romanian National Institute for Electrotechnics (ICPE) completely design and manufactured the prototype of the rotary magnetostrictive motor (RMM) necessary for the preliminary experimental assessment of theoretical results. This project represents a work in progress.
2017 Electric Vehicles International Conference (EV), 2017
In this paper is described a set of constraints applied to a wireless power-supply system (emitte... more In this paper is described a set of constraints applied to a wireless power-supply system (emitter and receiver) for operating in optimal conditions. These constraints regard both geometrical aspects and operational conditions of the system. There is also presented the performance optimization in the power wireless transfer. Starting from the equivalent scheme of a wireless power transfer system sinusoidal behavior, there are generated the system performances (the delivered active power or the system efficiency) in full symbolic and/or symbolic-numeric forms, obtaining an appropriate frequency space representation based on the complex or Laplace modified nodal equations (MNE) or/and Laplace state variable equations (SVE). In order to obtain the optimal values of the system parameters, that provide the maximum performances, there are used the MATLAB procedures which minimize these objective functions. These equations are combined with some measurements performed on the real system an...
Voltage controlled oscillators are present in the most of the digital communication system. In ou... more Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Researches are made so that a particular phase shift can be ches are made so that a particular phase shift can be ches are made so that a particular phase shift can be ches are made so that a particular phase shift can be obtained by choosing the free obtained by choosing the free obtained by choosi...
2018 International Conference on Applied and Theoretical Electricity (ICATE), 2018
This is a study presenting the impact of the long transmission lines or so-called feeders on the ... more This is a study presenting the impact of the long transmission lines or so-called feeders on the overvoltage distribution across power transformer windings. The overvoltage propagates along the power feeders until reaches a high voltage (HV) winding. The overvoltage is distributed across it. For the purpose of transient overvoltage evaluation, the HV winding model assumes distributed parameters. An equivalent circuit composed from series connected two-port elements substitutes the feeder. According to simulation results, the values of the line parameters play a significant role in determining the voltage across the HV winding. The strongly capacitive character of long feeders causes a larger voltage measured across the HV winding, compared to the line input. Moreover, the effective length of the transmission line is in direct correlation with the overvoltage amplitude across the HV winding. For this study, the model based upon lumped parameters and disk coils is suitable and provide...
2019 11th International Symposium on Advanced Topics in Electrical Engineering (ATEE), 2019
Abstract- For electric vehicles (EVs) on the move, the only viable solution of electromagnetic en... more Abstract- For electric vehicles (EVs) on the move, the only viable solution of electromagnetic energy charging consists of static and dynamic charging, where Inductive Power Transfer (IPT) offers possibilities that no other technology can match. The main objective of this paper is the analysis of the energy charging technologies for vehicles, using magnetically coupled coils. The main idea of such a system consists of an electrified driveway which offers the vehicles the possibility of moving and charging at the same time. The article presents the wireless power transfer principles followed by a presentation of inductive wireless power systems and an example of a parallel-series topology.
2021 12th International Symposium on Advanced Topics in Electrical Engineering (ATEE), 2021
Nonlinear circuits are very difficult to be analyzed because in many electronic circuits one deal... more Nonlinear circuits are very difficult to be analyzed because in many electronic circuits one deals with widely separated time scales (WSTS). To overcome this problem, a solution is to use variables in two time for the considered WSTS circuit. Consequently, it results that the differential algebraic equations will be become Multi-Time Partial Differential Equations - MTPDEs. To solve MTPDEs, for the dynamic circuits elements there are used resistive discrete equivalent circuits (companion circuits). An important attention is paid to the boundary condition used to solve MTPDEs and the simulation results are presented.
2016 International Conference on Applied and Theoretical Electricity (ICATE), 2016
This paper presents a study of the frequency splitting and bifurcation phenomena in the wireless ... more This paper presents a study of the frequency splitting and bifurcation phenomena in the wireless power transfer systems. Using electric circuit model methods and mathematical calculus, the two phenomena are analyzed for all the possible configurations of the coupled circuits, i.e. seriesseries, series-parallel, parallel-series and parallel-parallel. For a specific case including two identical printed coils, for each configuration some characteristics are represented graphically and the appearance of each phenomenon is commented. The analytical results and the numerical simulations are correlated and commented comparatively, in order to obtain useful conclusions.
2016 International Conference on Applied and Theoretical Electricity (ICATE), 2016
Our paper presents some procedures to optimize the performances of the two magnetically coupled c... more Our paper presents some procedures to optimize the performances of the two magnetically coupled coils used in the Wireless Power Transfer (WPT). The optimization of the two magnetically coupled coils is performed in function of their parameter values, for different structures, orientations, positions, and turn number of the two coils. Using the ANSYS Extractor Q3D Program the C, L, R, and G matrices, for different configurations, structures, frequencies and distances between coils, have been computed. For each structure we present the variations of: the active load power, the coupling coefficient, the active input power, and the efficiency in function of: the frequency, the horizontal distance and the vertical distance between the two coils, the angle, and the turn number. For each studied case we keep the same geometrical form of the conductors and the same conductor materials. Finally, comparing the obtained results we can select the optimal solution.
2015 International Symposium on Signals, Circuits and Systems (ISSCS), 2015
The paper is focused on the exact analysis of the frequency splitting and bifurcation phenomena i... more The paper is focused on the exact analysis of the frequency splitting and bifurcation phenomena in the wireless power transfer (WPT) systems with series-parallel, parallel-series and parallel-parallel resonators. Starting from the analysis in sinusoidal behavior of a WPT system we build, using the algebraic equation theory, the exact splitting mathematical model for any connection of the WPT systems and whether this phenomenon exists or not. It is also investigated the exact analysis of the frequency bifurcation phenomena and the relationship between frequency bifurcation and splitting for all connections named before. In this way it is possible to find exactly the splitting and bifurcation couplings. The splitting and bifurcation frequencies and the load power peak curves are computed with respect to the constructive parameters of the system. Finally, the theoretical results are validated by numerical simulations.
Lucrarea prezintă o metodă noua de analiză a debitelor fluidului de răcire din maşinile electrice... more Lucrarea prezintă o metodă noua de analiză a debitelor fluidului de răcire din maşinile electrice. Metoda se bazează pe analogia dintre reţeaua de rezistenţe aerodinamice a sistemului de ventilaţie a unei maşini electrice şi un circuit electric neliniar echivalent, care conţine ...
The paper presents the simulation of the induction motor both in transient behavior and in steady... more The paper presents the simulation of the induction motor both in transient behavior and in steady-state. The transient behavior analysis is based on the state variable approach, the equations being formulated in symbolic normal form with respect to the orthogonal ...
2019 8th International Conference on Modern Power Systems (MPS)
This paper uses analytical, numerical and experimental procedures for investigating several effec... more This paper uses analytical, numerical and experimental procedures for investigating several effects of the unbalanced voltage supply on the motor performance. The analytical electrical model of the induction motor (IM), developed for positive and negative sequence is an appropriate instrument for the evaluation of the IM operation in conditions of unbalanced power supply. This model brings a coherent procedure for the calculating the unbalanced current, losses of each category, respectively the developed torque. Data from analytical calculations became input for numerical analysis of the motor using the Finite Element Method (FEM). The induction motor performance evaluation through experiments is meant to compare the predicted results and complete the investigation. Finally, the work comes with recommendations regarding the eventual rerating as well as protective equipment set-up.
2019 Electric Vehicles International Conference (EV)
This paper presents an inductive coupling system used to recharge the batteries of electric vehic... more This paper presents an inductive coupling system used to recharge the batteries of electric vehicles (EV) as well as the ultra-capacitors used as energy storage elements wirelessly. Although ultra-capacitors can quickly charge, the standard inductive coupled circuits provide maximum power only for specific load impedance. The value of this impedance depends on the geometrical dimensions of the coils, coils configuration, as well as the distance between them. Since an ultra-capacitor in the charging mode is equivalent to an instantaneously increasing impedance, the maximum power supplied to the ultra-capacitor involves a single point inside the charging range, resulting in better optimum charging time. The analysis of the inductive coupling theory reveals that the optimal load impedance can vary by adjusting the secondary coil inductance and the resonant tuning capacitance. The proposal to modify the optimal load impedance dynamically throughout the capacitor charging range consists of a three-tapped secondary coil. Furthermore, this paper aims to design and analyze optimal wireless battery loading systems for electronic devices. The construction of these optimal systems uses an inductive coupling architecture that has a multi-tapped secondary coil (receiver). In this case, there are multiple magnetic couplings between the emitting coil and the receiving coils and even between the receiving coils corresponding to each tap. Consequently, results in a dynamic change of the coils geometries to modify the optimum load impedance and maximize the active power transmitted to the load. A thorough comparison involving performances put face to face the wireless power transfer systems (WPTS) containing only two magnetically coupled coils with those with multi-tapped secondary coils (MTSC). The main conclusion reveals the advantages of inductive architecture with MTSC.
2017 International Conference on Modern Power Systems (MPS), 2017
Switched networks modelling lead very often to discontinuities of circuit's variables corresp... more Switched networks modelling lead very often to discontinuities of circuit's variables corresponding to switching time moments. This phenomenon is said to have inconsistent initial conditions (IIC). The IIC problem appears only for ideal switches in ideal circuits when, after switching, the circuit contains excess elements. As a consequence, Dirac delta functions and their derivatives can occur in the circuit's variables variations which are proportional with the discontinuous variables derivatives. This paper presents a very precise method for analyzing the dynamic circuits with IIC, method which has the advantage given by its simplicity. This approach is based on modified nodal method, modelling the ideal switches using time variable resistors. The described algorithm has been implemented in the general program for real switched networks rapid analysis.
2018 International Conference on Applied and Theoretical Electricity (ICATE), 2018
This paper presents a method of modeling the synchronous machine subjected to transient regimes. ... more This paper presents a method of modeling the synchronous machine subjected to transient regimes. Then, the obtained model is utilized to simulate the dynamic behavior of the high power synchronous generator in conditions of asynchronous operation and for sudden three-phase short circuit occurred at the stator winding terminals. The model is based on Park-Blondel equations expressed in canonical form. The equations are built considering the influence of the induced current into the massive rotor of the generator and the nonlinearity of the magnetization characteristic. For the fulfillment of the simulated cases, an implicit Gear algorithm of third order is applied for the integration of the equations. The results obtained through simulations performed using the proposed model, are compared to those obtained running the predefined model offered for the synchronous machine by Simulink package from MATLAB. In both cases identical simulation scenarios are considered.
2019 15th International Conference on Engineering of Modern Electric Systems (EMES), 2019
The subject of this paper is a practical example where the application of the scattering paramete... more The subject of this paper is a practical example where the application of the scattering parameters (SP) results in the active power transfer efficiency increase. The process of information transmission (propagation) improves, also. The efficiency assessment addresses the transfer function of a two-port network. The computation of the maximum power transferred to the load requires the application of the maximum active power transfer theorem. Furthermore, the results obtained applying the electric circuit theory are compared to those obtained through the S parameters method. Moreover, utilizing the SP is possible to determine the characteristic parameters of analog filters. In this way it is possible to compute the stop and pass frequency bands and classify the nature of the filters. In the domains of high and very high frequencies, SP can be easily measured using a Vector Network Analyzer (VNA). The SP offers an attractive procedure to solve linear circuits operating in the sinusoidal regime, with direct reference to multi-poles. Finally, simulation results regarding all of the above mentioned parameters have been compared with data obtained either experimentally or from literature.
2017 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) & 2017 Intl Aegean Conference on Electrical Machines and Power Electronics (ACEMP), 2017
The wireless power transfer systems (WPTS) work at frequencies between 20 kHz – 40 MHz. Consideri... more The wireless power transfer systems (WPTS) work at frequencies between 20 kHz – 40 MHz. Considering the system consisting of two magnetically coupled coils, used in WPTSs, as a passive linear two-port network (PL2PN) in harmonic state, this paper describes the possibility of using the scattering parameters S in generating the power gains between the two ports of these coils. The amplification (or attenuation) property of the PL2PN can be emphasised by comparing the active Pin - the power given by the PL2PN at its input, with PL - the active power transmitted to the load. By computing the most significant gains, we describe, in this paper, the practical use of S parameters in order to make more efficient the information propagation and transmission processes in the wireless electromagnetic energy transmission from the emitter to the receiver coils for WPTS. Starting from the correct formulation of S parameters, their generation takes place in an automatic manner, based on the corresp...
2019 International Conference on Electromechanical and Energy Systems (SIELMEN), 2019
The efficient utilization of the magnetostrictive elongation is a critical factor in achieving th... more The efficient utilization of the magnetostrictive elongation is a critical factor in achieving the highly performant operation of the magnetostrictive motors. There are two main conditions to be fulfilled for the magnetostrictive motor to be optimally designed. The first one requires a unique value for the permanent magnet field intensity and the intensity of the magnetic field at the half of the linear segment of the magnetostrictive characteristic. The second condition requires that the permanent magnet recoil line must stay the same. This paper presents an experimental method applied to a proposed prototype, intended for testing the magnetostrictive motors in operation. The utilization of mechanical characteristics determined the load setup for achieving meaningful data. The Romanian National Institute for Electrotechnics (ICPE) completely design and manufactured the prototype of the rotary magnetostrictive motor (RMM) necessary for the preliminary experimental assessment of theoretical results. This project represents a work in progress.
2017 Electric Vehicles International Conference (EV), 2017
In this paper is described a set of constraints applied to a wireless power-supply system (emitte... more In this paper is described a set of constraints applied to a wireless power-supply system (emitter and receiver) for operating in optimal conditions. These constraints regard both geometrical aspects and operational conditions of the system. There is also presented the performance optimization in the power wireless transfer. Starting from the equivalent scheme of a wireless power transfer system sinusoidal behavior, there are generated the system performances (the delivered active power or the system efficiency) in full symbolic and/or symbolic-numeric forms, obtaining an appropriate frequency space representation based on the complex or Laplace modified nodal equations (MNE) or/and Laplace state variable equations (SVE). In order to obtain the optimal values of the system parameters, that provide the maximum performances, there are used the MATLAB procedures which minimize these objective functions. These equations are combined with some measurements performed on the real system an...
Voltage controlled oscillators are present in the most of the digital communication system. In ou... more Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are Voltage controlled oscillators are present in the most of the digital communication system. In our days, they are used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Resear used to control the phase in microwave antenna arrays. Researches are made so that a particular phase shift can be ches are made so that a particular phase shift can be ches are made so that a particular phase shift can be ches are made so that a particular phase shift can be obtained by choosing the free obtained by choosing the free obtained by choosi...
2018 International Conference on Applied and Theoretical Electricity (ICATE), 2018
This is a study presenting the impact of the long transmission lines or so-called feeders on the ... more This is a study presenting the impact of the long transmission lines or so-called feeders on the overvoltage distribution across power transformer windings. The overvoltage propagates along the power feeders until reaches a high voltage (HV) winding. The overvoltage is distributed across it. For the purpose of transient overvoltage evaluation, the HV winding model assumes distributed parameters. An equivalent circuit composed from series connected two-port elements substitutes the feeder. According to simulation results, the values of the line parameters play a significant role in determining the voltage across the HV winding. The strongly capacitive character of long feeders causes a larger voltage measured across the HV winding, compared to the line input. Moreover, the effective length of the transmission line is in direct correlation with the overvoltage amplitude across the HV winding. For this study, the model based upon lumped parameters and disk coils is suitable and provide...
2019 11th International Symposium on Advanced Topics in Electrical Engineering (ATEE), 2019
Abstract- For electric vehicles (EVs) on the move, the only viable solution of electromagnetic en... more Abstract- For electric vehicles (EVs) on the move, the only viable solution of electromagnetic energy charging consists of static and dynamic charging, where Inductive Power Transfer (IPT) offers possibilities that no other technology can match. The main objective of this paper is the analysis of the energy charging technologies for vehicles, using magnetically coupled coils. The main idea of such a system consists of an electrified driveway which offers the vehicles the possibility of moving and charging at the same time. The article presents the wireless power transfer principles followed by a presentation of inductive wireless power systems and an example of a parallel-series topology.
2021 12th International Symposium on Advanced Topics in Electrical Engineering (ATEE), 2021
Nonlinear circuits are very difficult to be analyzed because in many electronic circuits one deal... more Nonlinear circuits are very difficult to be analyzed because in many electronic circuits one deals with widely separated time scales (WSTS). To overcome this problem, a solution is to use variables in two time for the considered WSTS circuit. Consequently, it results that the differential algebraic equations will be become Multi-Time Partial Differential Equations - MTPDEs. To solve MTPDEs, for the dynamic circuits elements there are used resistive discrete equivalent circuits (companion circuits). An important attention is paid to the boundary condition used to solve MTPDEs and the simulation results are presented.
2016 International Conference on Applied and Theoretical Electricity (ICATE), 2016
This paper presents a study of the frequency splitting and bifurcation phenomena in the wireless ... more This paper presents a study of the frequency splitting and bifurcation phenomena in the wireless power transfer systems. Using electric circuit model methods and mathematical calculus, the two phenomena are analyzed for all the possible configurations of the coupled circuits, i.e. seriesseries, series-parallel, parallel-series and parallel-parallel. For a specific case including two identical printed coils, for each configuration some characteristics are represented graphically and the appearance of each phenomenon is commented. The analytical results and the numerical simulations are correlated and commented comparatively, in order to obtain useful conclusions.
2016 International Conference on Applied and Theoretical Electricity (ICATE), 2016
Our paper presents some procedures to optimize the performances of the two magnetically coupled c... more Our paper presents some procedures to optimize the performances of the two magnetically coupled coils used in the Wireless Power Transfer (WPT). The optimization of the two magnetically coupled coils is performed in function of their parameter values, for different structures, orientations, positions, and turn number of the two coils. Using the ANSYS Extractor Q3D Program the C, L, R, and G matrices, for different configurations, structures, frequencies and distances between coils, have been computed. For each structure we present the variations of: the active load power, the coupling coefficient, the active input power, and the efficiency in function of: the frequency, the horizontal distance and the vertical distance between the two coils, the angle, and the turn number. For each studied case we keep the same geometrical form of the conductors and the same conductor materials. Finally, comparing the obtained results we can select the optimal solution.
2015 International Symposium on Signals, Circuits and Systems (ISSCS), 2015
The paper is focused on the exact analysis of the frequency splitting and bifurcation phenomena i... more The paper is focused on the exact analysis of the frequency splitting and bifurcation phenomena in the wireless power transfer (WPT) systems with series-parallel, parallel-series and parallel-parallel resonators. Starting from the analysis in sinusoidal behavior of a WPT system we build, using the algebraic equation theory, the exact splitting mathematical model for any connection of the WPT systems and whether this phenomenon exists or not. It is also investigated the exact analysis of the frequency bifurcation phenomena and the relationship between frequency bifurcation and splitting for all connections named before. In this way it is possible to find exactly the splitting and bifurcation couplings. The splitting and bifurcation frequencies and the load power peak curves are computed with respect to the constructive parameters of the system. Finally, the theoretical results are validated by numerical simulations.
Lucrarea prezintă o metodă noua de analiză a debitelor fluidului de răcire din maşinile electrice... more Lucrarea prezintă o metodă noua de analiză a debitelor fluidului de răcire din maşinile electrice. Metoda se bazează pe analogia dintre reţeaua de rezistenţe aerodinamice a sistemului de ventilaţie a unei maşini electrice şi un circuit electric neliniar echivalent, care conţine ...
The paper presents the simulation of the induction motor both in transient behavior and in steady... more The paper presents the simulation of the induction motor both in transient behavior and in steady-state. The transient behavior analysis is based on the state variable approach, the equations being formulated in symbolic normal form with respect to the orthogonal ...
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