| 1. |
- Cosic, Alija, et al.
(author)
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3D Analyses of a Novel Transverse Flux Machine for a Free Piston Energy Converter
- 2009
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In: ICEM. - NEW YORK : IEEE. - 9781424417353 ; , s. 324-329
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Conference paper (peer-reviewed)abstract
- The electrical machine is one of the key parts in the Free Piston Energy Converter (FPEC), and as such the electrical machine faces very tough requirements such as low weight of the translator and high power density. During the design process great emphasis has been put not only on the machine performance but also on the manufacturing process. This paper investigates a novel Transverse Flux Linear machine for the FPEC application. At first, the analytical calculations are performed based on some estimation of the leakage flux in the machine. However, during the FEM analysis and measurements it was obvious that a more detailed analysis was required in order to achieve a better agreement in results. A more detailed reluctance network is developed and used for the analysis. The results are compared with both FEM simulations and the measurements.
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| 2. |
- Cosic, Alija, 1977-, et al.
(author)
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A novel concept of a Transverse Flux Linear Free-Piston Generator
- 2005
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Conference paper (peer-reviewed)abstract
- This paper investigates the electrical machine, which is one of the important parts in the FreePiston Energy Converter (FPEC). In the previous work it was found that one of the best candidate suitablefor the FPEC is a Transverse Flux Machine (TFM) due to the very tough requirements on the electrical ma-chine such as a low weight of the translator (movable part in the machine).This paper presents a new conceptof a linear TFM in which strong emphasis has been put to achieve a design that is simple to manufacture.Different types of the magnet confgurations on the translator have been investigated. It has been found thatthe buried magnet design suffers from a very high leakage to the nearby poles and is thus not suitable forthis type of machine. Another confguration, which has been investigated, is the surface mounted magnetconfguration. Analytical models for this confguration have been established. It has been found that thetough requirements, 4kN from a 6kg movable mass, can be achieved at the required speed, specifc powerand effciency
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| 3. |
- Cosic, Alija, 1977-
(author)
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Analysis of a novel Transversal Flux Machine with a tubular cross-section for Free Piston Energy Converter application
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Constantly growing need for oil, all over the world, has caused oil price to rise rapidly during the last decade. High oil prices have made fuel economy as one of the most important factors when consumers are buying their cars today. Realizing this, many car manufacturers have developed or are looking for some alternative solutions in order to decrease fuel consumption. Combining two different technologies in a vehicle, the so called hybrid vehicle, can be seen as the first step toward a better and more sustainable development. There are several different solutions for hybrid vehicles today, among the best known are the Serie Electric Hybrid Vehicle (SEHV), the Parallel Electric Hybrid Vehicle (PEHV) and the Serie-Parallel Hybrid Electric Vehicle (SPEHV). By integrating a combustion engine with a linear electric machine into one unit, a system that is called Free Piston Energy Converter (FPEC) is achieved. The FPEC is suitable for use in a SEHV. Other application areas like stand alone generator are also possible. In this report a novel Transverse Flux Machine (TFM) with a tubular cross section of the translator has been investigated. Application of the machine in a FPEC has put tough requirement on the translator weight, specific power and force density. Different configurations of the winding arrangements as well as the magne tarrangement have been investigated. It has been concluded that the buried magnet design suffers from high leakage flux and is thus not asuitable TFM concept. Instead the surface mounted magnet design has been chosen for further investigation. An analytical model has been developed and a prototype machine has been built based on the analytical results. In order to have a better understanding of the machine characteristic a 3D-FEM analysis has been performed. The results from the analytical model, FEM model and measurements are analyzed and compared. The comparison between the measured and FEM-simulated results shows very good agreement. Furthermore, the results from the analytical model indicates that it can be successfully developed for further analysis and optimization of the design to give a cost-effective solution of the novel generato for mass production.
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| 4. |
- Cosic, Alija, 1977-, et al.
(author)
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APPLICATION OF A FREE-PISTON GENERATOR IN A SERIES HYBRID VEHICLE
- 2003
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In: Proceedings of the 4th international Symposium on Linear Drives for Industry Applications. ; , s. 541-544
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Conference paper (peer-reviewed)abstract
- This paper deals with an investigation of differentcontrol strategies for a series hybrid electric vehicle (SHEV).Another discussed issue is the application of a free-pistongenerator. By replacing a conventional combustion enginewith a free-piston generator it is possible to increase the totalefficiency of the system. The object of investigation is a12-ton truck, mainly used in urban areas. The drive systemhas been built up and simulated in a MATLAB Simulinkenvironment. It follows from the investigation that theapplication of a free-piston engine in a SEHV can increasethe efficiency by 25 percent compared to the conventionalengine.
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| 5. |
- Cosic, Alija, 1977-, et al.
(author)
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Cogging torque calculations for a novel concept of a Transverse Flux Linear Free-Piston Generator
- 2007
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Conference paper (peer-reviewed)abstract
- This paper investigates cogging force in a linear Transverse Flux Machine, TFM. 3D-FEM and 2D-FEM simulations has been performed and also two analytical methods have been applied. The analytical methods are based on the reluctant pressure method. Once the ¯eld distribution on the side of the tooth is known, the cogging force can be calculated by integrating the ¯eld. The agreement between the 2D-FEM and Conformal Mapping, CM, analytical method is good. However the 3D-FEM simulation results indicates a lower cogging force than the other two methods.
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| 6. |
- Cosic, Alija, et al.
(author)
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Construction of a rotating power electronic converter for induction machine operation
- 2015
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Conference paper (peer-reviewed)abstract
- This paper describes the construction of the rotating power electronic converter. By mounting the power electronics on the rotor of an induction machine, the rotor winding can be made easily accessible without the use of slip-rings and brushes. This offers certain advantages regarding motor control. However, it is evident that the rotating mass, communication with the converter and maintaining the mechanical stability and reliability of the system are huge challenges that must be overcome. This paper describes some solution that are partly investigated and some solutions that still needs to be investigated in more detail.
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| 7. |
- Cosic, Alija, et al.
(author)
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Design and manufacturing of a linear Transverse Flux Permanent Magnet Machines
- 2008
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In: 2008 IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING. - 9781424422784 ; , s. 726-730
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Conference paper (peer-reviewed)abstract
- In general Transverse Flux Machines (TFM) are considered to be complex and difficult to manufacture. However, there are some exceptions. In the linear TFM the flux plane is the same as for the conventional rotating electrical machine. Therefore, iron laminations from conventional rotating machines can be used to manufacture the stator. The manufacturing process of the stator becomes then more simple compared to the manufacturing process of the conventional linear machine. This paper deals with a novel design of a linear TFM machine for the free piston energy converter application. It describes earlier designed and manufactured prototypes and a new manufacturing approach in order to avoid the loss in flux and thereby also loss in the force production.
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| 8. |
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| 9. |
- Malik, Naveed ur Rehman, 1985-, et al.
(author)
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Experimental Validation of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator for Variable-Speed Operation
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Other publication (other academic/artistic)abstract
- This paper investigates through experiments a differenttopology of a brushless doubly-fed induction generatorwith a rotating power electronic converter: the rotatingpower electronic brushless doubly-fed induction generator (RPEBDFIG),operated with variable speed and torque. The theorybehind the operation of the generator is presented, its dynamicmodel and control aspects are discussed, and closed-loop controlof the generator is implemented and verified through experimentson an 11-kW prototype. The measurement results show stableoperation for variable speed and torque regions. Moreover, itis shown that the integrated rotating exciter is sufficient torecover slip power and deliver to the grid, hence, verifyingsuccessful brushless operation. Besides, it is verified that thegenerator operates well in both regions of operation, i.e., the subsynchronousand super-synchronous modes, and is stable undertorque transients added by the rotating exciter.
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| 10. |
- Malik, Naveed ur Rehman, 1985-, et al.
(author)
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Induction Machine at Unity Power Factor with Rotating Power Electronic Converter
- 2012
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Conference paper (peer-reviewed)abstract
- A new configuration for the self-excitation of the induction machine invented by Magnus Lindmark is presented. The power electronic converter using solid state switches is connected to the rotor while the stator is directly connected to the grid. Using appropriate control, the reactive power consumed by the motor can be generated in the rotor resulting in unity power factor operation. The rotor connected power electronic converter is also used for constant speed operation of the induction machine at variable torque.
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