Bogdan Varaticeanu - Academia.edu (original) (raw)

Papers by Bogdan Varaticeanu

2022 ELEKTRO (ELEKTRO), May 23, 2022

This paper describes the design and optimization of a 7.5 kW Permanent Magnet Assisted Synchronou... more This paper describes the design and optimization of a 7.5 kW Permanent Magnet Assisted Synchronous Reluctance Motor (PMASynRM) that works with ferrite magnets. The suitable stator and rotor configuration for high torque combined with reduced ripple is also analyzed in this paper. The design relies on some of the best practice presented in literature that are used to increase the PMASynRM performance. Finite element analysis is used to optimize the rotor structure in term of torque production and for performance prediction. The PMASynRM electromagnetic losses are investigated in order to increase the motor efficiency.

Electrotehnică, electronică, automatică, Feb 15, 2021

Brushless servomotors are widely used in industry and in all domains that require precise and eas... more Brushless servomotors are widely used in industry and in all domains that require precise and easy position/speed/torque control. To further improve the performance of these motors, the segmentation of the stator core is taken into account. This approach to core construction provides a high slot fill factor, compact design, and efficient use of materials. This paper aims to present that the manufacturing constraints and tolerances of this particular core construction can increase unwanted effects in brushless motors, like cogging torque, torque ripple and their influence regarding the back-EMF. Two models for a 12slots-10 pole configuration, one with segmented core and one with standard laminated core are compared and analysed using the FEA (Finite Element Analysis) method. The influence of the additional air gaps that occur in such constructions is investigated to provide an overview for the design of segmented motors. Various lengths for air gaps between the segments of the core are taken into consideration and non-uniform distribution of such gaps. The paper also provides further steps that must be taken in order to verify/validate the studied model’s impact on motor design.

2021 9th International Conference on Modern Power Systems (MPS), Jun 16, 2021

The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batter... more The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batteries to ones using 400V or higher. In this paper, two electric machines supplied with a 560V DC-link will be designed and optimized using a classic design approach and using a 120V DC-link supplied electric machine as reference. As the market for rare earth magnets is in decline, the proposed machine type is a Synchronous Reluctance Machine (SynRM) assisted with Ferrite magnets placed in the flux barriers. A comparison is performed between the two machine variants using the FEA method, in order to validate the performances of the machines.

In the paper is presented the design of a brushless servomotor, which has its stator made of soft... more In the paper is presented the design of a brushless servomotor, which has its stator made of soft magnetic composite Somaloy 700-3P 600 MPa. This motor will have an industrial purpose in special applications. The finite element method is suitable for a first analyze in the manufacture process and in this step adequate materials are chosen. The cogging torque has low values, fact that proves that motor is a robust one and it has a low-cost integration.

Electrotehnica, Electronica, Automatica, 2020

The paper puts in perspective the aspects of classic valve construction and the use of off-the-sh... more The paper puts in perspective the aspects of classic valve construction and the use of off-the-shelf products in order to improve the valve's features in terms of user interface, valve status in operating conditions and control interface to classic standardized communication protocols, such as EtherCAT®, ProfiBUS®. Because the resulting products are meant to be functional prototypes, most parts used for implementing new features will not be fully developed as for a sellable product, but only to the stage of proof-of-concept. To fully develop the used equipment will imply a dedicated study, which would allow the shift from general purpose use development boards and breakout sensor boards to application-specific equipment designed for assembly line manufacturing. The same study includes the use of Internet-of-Things in industrial environment and will be the subject of separate and dedicated article. The paper only mentions the possibilities and ways of achieving future design ideas.

2007 IEEE Industry Applications Annual Meeting, 2007

Electrotehnică, electronică, automatică, Sep 1, 2020

The paper puts in perspective the aspects of classic valve construction and the use of off-the-sh... more The paper puts in perspective the aspects of classic valve construction and the use of off-the-shelf products in order to improve the valve's features in terms of user interface, valve status in operating conditions and control interface to classic standardized communication protocols, such as EtherCAT®, ProfiBUS®. Because the resulting products are meant to be functional prototypes, most parts used for implementing new features will not be fully developed as for a sellable product, but only to the stage of proof-of-concept. To fully develop the used equipment will imply a dedicated study, which would allow the shift from general purpose use development boards and breakout sensor boards to application-specific equipment designed for assembly line manufacturing. The same study includes the use of Internet-of-Things in industrial environment and will be the subject of separate and dedicated article. The paper only mentions the possibilities and ways of achieving future design ideas.

2020 International Symposium on Fundamentals of Electrical Engineering (ISFEE)

In the paper is presented the design of a brushless servomotor, which has its stator made of soft... more In the paper is presented the design of a brushless servomotor, which has its stator made of soft magnetic composite Somaloy 700-3P 600 MPa. This motor will have an industrial purpose in special applications. The finite element method is suitable for a first analyze in the manufacture process and in this step adequate materials are chosen. The cogging torque has low values, fact that proves that motor is a robust one and it has a low-cost integration.

Electrical Engineering in Japan, 2003

Permanent magnet motors have attracted a lot of attention recently for their potential energy sav... more Permanent magnet motors have attracted a lot of attention recently for their potential energy saving. However, they are only used for certain applications because of expensive magnets. This paper discuss the optimum design of the low cost and highly efficient magnet assisted reluctance motors with a minimum amount of magnets. The motor considered in this study is a multi flux barrier reluctance motor. The configuration by which permanent magnets are embedded to the innermost side of the rotor to obtain maximum output with the minimum amount of magnets was evaluated through simulation and experiments with a prototype motor. As a result, we established a method for designing motors capable of realizing the same efficiency as permanent magnet motors with only one-fourth the amount of magnets. In our experiments, we achieved a high efficiency of 94.5% with a 750W motor.

2019 Electric Vehicles International Conference (EV), 2019

This paper presents the electromagnetic design of a low power outer rotor synchronous reluctance ... more This paper presents the electromagnetic design of a low power outer rotor synchronous reluctance machine. It is well known that the form and the number of flux barriers influence the electrical (power factor, saliency ratio) and mechanical (torque, torque ripple) performances of the synchronous reluctance machine. For this study has been investigated the influence of different number of barriers on different rotor pole. Also, the form of the flux barriers will be change for half of the rotor poles. To characterize the outer rotor synchronous reluctance machine magneto-static and transient-magnetic simulation are compute.

2017 Electric Vehicles International Conference (EV), 2017

The paper describes the design and the experimental validation of an electric naval propulsion sy... more The paper describes the design and the experimental validation of an electric naval propulsion system with rim driven propeller. The electric naval propulsion system is submerged in water providing an effective cooling for the electric machine and thus achieving a high power density. The proposed slotless design of the permanent magnet (PM) machine allows a convenient way to protect the motors' active parts against water. For accurate prediction of PM machine electromagnetic performances, finite element method (FEM) was used.

2019 Electric Vehicles International Conference (EV), 2019

Permanent magnet Vernier machines (PMVM) are getting more and more attention due to the propulsio... more Permanent magnet Vernier machines (PMVM) are getting more and more attention due to the propulsion of light electric vehicles (EVs) provided by high torque at low speed. The purpose of this paper is to compare and analyze the optimal structure in order to develop a new type of dual stator machine with high performances due to the stator and the rotor configuration. For the presented structures used as a motor were examined the magnetization of the cores, the flux line distribution, the magnetic flux density in the air gaps, the variation of the electromagnetic torque in time and the variation of currents phase in time. Because of the in wheel condition, the windings of the stator were kept inside. The structure with the best performances was analyzed as a generator.

2020 International Conference on Electrical Machines (ICEM), 2020

Electrical machine electromagnetic-caused noise and vibration represents an ever-increasing targe... more Electrical machine electromagnetic-caused noise and vibration represents an ever-increasing target for machine-designers. A novel late design-stage NVH optimization method using the full rotational velocity synthesized vibration-response map is proposed. This is assisted by a target-setting method for the most important force harmonics using a force sensitivity analysis. The procedure is applied on a PMASynRM used for light traction applications, where the rotor cross-section is modified by introducing notches and saliency. The results for different percentages of permitted decrease in average show that both resonances and individual frequency orders can be directly targeted and minimized.

In the paper is presented a numerical analysis of a free rare-earth permanent magnet assisted syn... more In the paper is presented a numerical analysis of a free rare-earth permanent magnet assisted synchronous reluctance machine (PMaSynRM). It will be analyzed a geometrical configuration with six poles on the rotor, whose permanent magnets are made of SrO6Fe2O3. Usually, electric vehicles need reliable and resilient electric motors and today it is a worldwide trend that consists of rare-earth free electrical machines. The efficiency and torque density have to be investigated and optimized, so as a consequence the entire cost of the motor could be reduced. PMaSynRM machine is designed using finite element method (FEM) simulation. The proposed configuration presented in the paper, is analyzed, by taking into account the generator working conditions, as a first step in the new machine configuration design. The cogging torque is computed, using FEM simulations and the three phased electrical voltages are presented.

2018 International Conference and Exposition on Electrical And Power Engineering (EPE), 2018

Chronic and image: visual representation of Monsivais of the urban and the contradictions of the ... more Chronic and image: visual representation of Monsivais of the urban and the contradictions of the Mexican modernity Jairol Núñez Moya * RESUMEN El trabajo explora el uso de la imagen en la crónica de Carlos Monsiváis, particularmente en Los rituales del caos (1995), donde la protagonista es la ciudad. En su propuesta, la crónica resulta insuficiente y recurre a compilar imágenes que documentan sus temas e ideas, con el fin de fortalecer su crítica de la realidad social. El cronista realiza no sólo un ejercicio de escritura sino la elaboración de un discurso que toma como base el contexto. En el texto las imágenes nos acercan a lo abordado en las crónicas, dan cuenta de la pluralidad cultural y de los cambios que se han gestado en la sociedad mexicana, lo cual posibita una reflexión sobre las contradicciones de la Modernidad.

2021 9th International Conference on Modern Power Systems (MPS), 2021

The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batter... more The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batteries to ones using 400V or higher. In this paper, two electric machines supplied with a 560V DC-link will be designed and optimized using a classic design approach and using a 120V DC-link supplied electric machine as reference. As the market for rare earth magnets is in decline, the proposed machine type is a Synchronous Reluctance Machine (SynRM) assisted with Ferrite magnets placed in the flux barriers. A comparison is performed between the two machine variants using the FEA method, in order to validate the performances of the machines.

Lecture Notes in Mobility, 2015

2022 ELEKTRO (ELEKTRO), May 23, 2022

This paper describes the design and optimization of a 7.5 kW Permanent Magnet Assisted Synchronou... more This paper describes the design and optimization of a 7.5 kW Permanent Magnet Assisted Synchronous Reluctance Motor (PMASynRM) that works with ferrite magnets. The suitable stator and rotor configuration for high torque combined with reduced ripple is also analyzed in this paper. The design relies on some of the best practice presented in literature that are used to increase the PMASynRM performance. Finite element analysis is used to optimize the rotor structure in term of torque production and for performance prediction. The PMASynRM electromagnetic losses are investigated in order to increase the motor efficiency.

Electrotehnică, electronică, automatică, Feb 15, 2021

Brushless servomotors are widely used in industry and in all domains that require precise and eas... more Brushless servomotors are widely used in industry and in all domains that require precise and easy position/speed/torque control. To further improve the performance of these motors, the segmentation of the stator core is taken into account. This approach to core construction provides a high slot fill factor, compact design, and efficient use of materials. This paper aims to present that the manufacturing constraints and tolerances of this particular core construction can increase unwanted effects in brushless motors, like cogging torque, torque ripple and their influence regarding the back-EMF. Two models for a 12slots-10 pole configuration, one with segmented core and one with standard laminated core are compared and analysed using the FEA (Finite Element Analysis) method. The influence of the additional air gaps that occur in such constructions is investigated to provide an overview for the design of segmented motors. Various lengths for air gaps between the segments of the core are taken into consideration and non-uniform distribution of such gaps. The paper also provides further steps that must be taken in order to verify/validate the studied model’s impact on motor design.

2021 9th International Conference on Modern Power Systems (MPS), Jun 16, 2021

The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batter... more The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batteries to ones using 400V or higher. In this paper, two electric machines supplied with a 560V DC-link will be designed and optimized using a classic design approach and using a 120V DC-link supplied electric machine as reference. As the market for rare earth magnets is in decline, the proposed machine type is a Synchronous Reluctance Machine (SynRM) assisted with Ferrite magnets placed in the flux barriers. A comparison is performed between the two machine variants using the FEA method, in order to validate the performances of the machines.

In the paper is presented the design of a brushless servomotor, which has its stator made of soft... more In the paper is presented the design of a brushless servomotor, which has its stator made of soft magnetic composite Somaloy 700-3P 600 MPa. This motor will have an industrial purpose in special applications. The finite element method is suitable for a first analyze in the manufacture process and in this step adequate materials are chosen. The cogging torque has low values, fact that proves that motor is a robust one and it has a low-cost integration.

Electrotehnica, Electronica, Automatica, 2020

The paper puts in perspective the aspects of classic valve construction and the use of off-the-sh... more The paper puts in perspective the aspects of classic valve construction and the use of off-the-shelf products in order to improve the valve's features in terms of user interface, valve status in operating conditions and control interface to classic standardized communication protocols, such as EtherCAT®, ProfiBUS®. Because the resulting products are meant to be functional prototypes, most parts used for implementing new features will not be fully developed as for a sellable product, but only to the stage of proof-of-concept. To fully develop the used equipment will imply a dedicated study, which would allow the shift from general purpose use development boards and breakout sensor boards to application-specific equipment designed for assembly line manufacturing. The same study includes the use of Internet-of-Things in industrial environment and will be the subject of separate and dedicated article. The paper only mentions the possibilities and ways of achieving future design ideas.

2007 IEEE Industry Applications Annual Meeting, 2007

Electrotehnică, electronică, automatică, Sep 1, 2020

The paper puts in perspective the aspects of classic valve construction and the use of off-the-sh... more The paper puts in perspective the aspects of classic valve construction and the use of off-the-shelf products in order to improve the valve's features in terms of user interface, valve status in operating conditions and control interface to classic standardized communication protocols, such as EtherCAT®, ProfiBUS®. Because the resulting products are meant to be functional prototypes, most parts used for implementing new features will not be fully developed as for a sellable product, but only to the stage of proof-of-concept. To fully develop the used equipment will imply a dedicated study, which would allow the shift from general purpose use development boards and breakout sensor boards to application-specific equipment designed for assembly line manufacturing. The same study includes the use of Internet-of-Things in industrial environment and will be the subject of separate and dedicated article. The paper only mentions the possibilities and ways of achieving future design ideas.

2020 International Symposium on Fundamentals of Electrical Engineering (ISFEE)

In the paper is presented the design of a brushless servomotor, which has its stator made of soft... more In the paper is presented the design of a brushless servomotor, which has its stator made of soft magnetic composite Somaloy 700-3P 600 MPa. This motor will have an industrial purpose in special applications. The finite element method is suitable for a first analyze in the manufacture process and in this step adequate materials are chosen. The cogging torque has low values, fact that proves that motor is a robust one and it has a low-cost integration.

Electrical Engineering in Japan, 2003

Permanent magnet motors have attracted a lot of attention recently for their potential energy sav... more Permanent magnet motors have attracted a lot of attention recently for their potential energy saving. However, they are only used for certain applications because of expensive magnets. This paper discuss the optimum design of the low cost and highly efficient magnet assisted reluctance motors with a minimum amount of magnets. The motor considered in this study is a multi flux barrier reluctance motor. The configuration by which permanent magnets are embedded to the innermost side of the rotor to obtain maximum output with the minimum amount of magnets was evaluated through simulation and experiments with a prototype motor. As a result, we established a method for designing motors capable of realizing the same efficiency as permanent magnet motors with only one-fourth the amount of magnets. In our experiments, we achieved a high efficiency of 94.5% with a 750W motor.

2019 Electric Vehicles International Conference (EV), 2019

This paper presents the electromagnetic design of a low power outer rotor synchronous reluctance ... more This paper presents the electromagnetic design of a low power outer rotor synchronous reluctance machine. It is well known that the form and the number of flux barriers influence the electrical (power factor, saliency ratio) and mechanical (torque, torque ripple) performances of the synchronous reluctance machine. For this study has been investigated the influence of different number of barriers on different rotor pole. Also, the form of the flux barriers will be change for half of the rotor poles. To characterize the outer rotor synchronous reluctance machine magneto-static and transient-magnetic simulation are compute.

2017 Electric Vehicles International Conference (EV), 2017

The paper describes the design and the experimental validation of an electric naval propulsion sy... more The paper describes the design and the experimental validation of an electric naval propulsion system with rim driven propeller. The electric naval propulsion system is submerged in water providing an effective cooling for the electric machine and thus achieving a high power density. The proposed slotless design of the permanent magnet (PM) machine allows a convenient way to protect the motors' active parts against water. For accurate prediction of PM machine electromagnetic performances, finite element method (FEM) was used.

2019 Electric Vehicles International Conference (EV), 2019

Permanent magnet Vernier machines (PMVM) are getting more and more attention due to the propulsio... more Permanent magnet Vernier machines (PMVM) are getting more and more attention due to the propulsion of light electric vehicles (EVs) provided by high torque at low speed. The purpose of this paper is to compare and analyze the optimal structure in order to develop a new type of dual stator machine with high performances due to the stator and the rotor configuration. For the presented structures used as a motor were examined the magnetization of the cores, the flux line distribution, the magnetic flux density in the air gaps, the variation of the electromagnetic torque in time and the variation of currents phase in time. Because of the in wheel condition, the windings of the stator were kept inside. The structure with the best performances was analyzed as a generator.

2020 International Conference on Electrical Machines (ICEM), 2020

Electrical machine electromagnetic-caused noise and vibration represents an ever-increasing targe... more Electrical machine electromagnetic-caused noise and vibration represents an ever-increasing target for machine-designers. A novel late design-stage NVH optimization method using the full rotational velocity synthesized vibration-response map is proposed. This is assisted by a target-setting method for the most important force harmonics using a force sensitivity analysis. The procedure is applied on a PMASynRM used for light traction applications, where the rotor cross-section is modified by introducing notches and saliency. The results for different percentages of permitted decrease in average show that both resonances and individual frequency orders can be directly targeted and minimized.

In the paper is presented a numerical analysis of a free rare-earth permanent magnet assisted syn... more In the paper is presented a numerical analysis of a free rare-earth permanent magnet assisted synchronous reluctance machine (PMaSynRM). It will be analyzed a geometrical configuration with six poles on the rotor, whose permanent magnets are made of SrO6Fe2O3. Usually, electric vehicles need reliable and resilient electric motors and today it is a worldwide trend that consists of rare-earth free electrical machines. The efficiency and torque density have to be investigated and optimized, so as a consequence the entire cost of the motor could be reduced. PMaSynRM machine is designed using finite element method (FEM) simulation. The proposed configuration presented in the paper, is analyzed, by taking into account the generator working conditions, as a first step in the new machine configuration design. The cogging torque is computed, using FEM simulations and the three phased electrical voltages are presented.

2018 International Conference and Exposition on Electrical And Power Engineering (EPE), 2018

Chronic and image: visual representation of Monsivais of the urban and the contradictions of the ... more Chronic and image: visual representation of Monsivais of the urban and the contradictions of the Mexican modernity Jairol Núñez Moya * RESUMEN El trabajo explora el uso de la imagen en la crónica de Carlos Monsiváis, particularmente en Los rituales del caos (1995), donde la protagonista es la ciudad. En su propuesta, la crónica resulta insuficiente y recurre a compilar imágenes que documentan sus temas e ideas, con el fin de fortalecer su crítica de la realidad social. El cronista realiza no sólo un ejercicio de escritura sino la elaboración de un discurso que toma como base el contexto. En el texto las imágenes nos acercan a lo abordado en las crónicas, dan cuenta de la pluralidad cultural y de los cambios que se han gestado en la sociedad mexicana, lo cual posibita una reflexión sobre las contradicciones de la Modernidad.

2021 9th International Conference on Modern Power Systems (MPS), 2021

The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batter... more The battery voltage in Electric or hybrid vehicles is switching from the classic 24 or 48V batteries to ones using 400V or higher. In this paper, two electric machines supplied with a 560V DC-link will be designed and optimized using a classic design approach and using a 120V DC-link supplied electric machine as reference. As the market for rare earth magnets is in decline, the proposed machine type is a Synchronous Reluctance Machine (SynRM) assisted with Ferrite magnets placed in the flux barriers. A comparison is performed between the two machine variants using the FEA method, in order to validate the performances of the machines.

Lecture Notes in Mobility, 2015