M. Ruba

Universitatea Tehnica Cluj-Napoca, Klausenburg, Cluj, Romania

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Publications (37)4.91 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper details the background of design, modeling, building and experimental validation of a low power switched reluctance machine (SRM) together with its attached custom made electronic converter. Aspects regarding the design of the machine highlight the main analytical involved procedures. The model of the machine is firstly validated through simulation wise involving two strategies, one based on finite element analysis (FEA) and one based on a complex Matlab/Simulink model. The building of the machine is also presented in the paper. In order to validate the studied system via experimental tests, a custom made electronic power converter was built based on high current MOSFET type power switches. The control of the converter was accomplished using a dSPACE 1103 board. The position and speed sensing of the machine is based on a resolver type sensor. Preliminary, simple hysteresis control was involved in order to validate the developed torque of the machine at different velocities.
    2014 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM 2014); 06/2014
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    ABSTRACT: The switched reluctance motor (SRM) has inherently high level of fault tolerance. However despite of its high robustness and reliability it can face windings and bearings faults. The faults can cause costly downtimes in industrial environment, or they can bring about more severe consequences in safety critical applications. Therefore the detection of the faults in their incipient phase and the ability to tolerate them is a very important requirement for the electrical drive systems used in such applications. The paper deals with the most important faults of the SRMs, their effects on the machine performances and their detection. Also a reconfigurable fault tolerant control system for the SRMs is proposed, which is able to detect diverse winding faults and to mask these faults by imposing increased currents in the healthy remained coils of the machine. The fault detection capability and the correct reconfiguration of the proposed control system are proved by laboratory tests.
    07/2013; 1(2):16-25.
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    ABSTRACT: The switched reluctance motor (SRM) has inherently high level of fault tolerance. However despite of its high robustness and reliability it can face windings and bearings faults. The faults can cause costly downtimes in industrial environment, or they can bring about more severe consequences in safety critical applications. Therefore the detection of the faults in their incipient phase and the ability to tolerate them is a very important requirement for the electrical drive systems used in such applications. The paper deals with the most important faults of the SRMs, their effects on the machine performances and their detection. Also a reconfigurable fault tolerant control system for the SRMs is proposed, which is able to detect diverse winding faults and to mask these faults by imposing increased currents in the healthy remained coils of the machine. The fault detection capability and the correct reconfiguration of the proposed control system are proved by laboratory tests.
    06/2013; 1(2):16-25.
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    ABSTRACT: In the paper, a reconfigurable fault tolerant control system for a segmental stator switched reluctance machine is proposed. It can detect diverse winding faults and mask these faults by means of imposing increased currents in the healthy remained coils of the machine. The reconfiguration strategy depends on the type of the winding fault. By applying the proposed reconfiguration of the control strategy the continuation of the machine's movement can be assured despite of winding faults of diverse severity. The main hardware and software components of the control system are detailed in length in the paper. The correct reconfiguration is proved by laboratory measurements performed on a test bench specially built up for this purpose. The developed control system can be applied in safety-critical electrical equipment.
    01/2013; 1(1):1-8.
  • M. Ruba, D. Fodorean
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    ABSTRACT: The present paper deals with the design, finite element analysis (FEA) validation and the direct instantaneous torque control (DITC) if a low voltage switched reluctance machine (SRM) for small automotive applications. The machine proposed is a low voltage and high current structure able to develop the power requested by the application. The design procedure meets difficulties and solves them in manner of core saturation at high current and high power density. The analytical design procedure is detailed for the proposed machine. Discussing of high phase currents, a validation of the design needs to be approached, based on FEA method. The direct instantaneous torque control (DITC) is employed as the machine is addressed to automotive applications. As it is known that the torque ripples of the SRM are high when using only hysteresis control of the currents hence these will create discomfort to the driver. With DITC, the torque can be smoothened in order to obtain increased comfort of the passenger. In order to implement DITC method, a Matlab Simulink program was created to simulate the SRM, based on lookup tables containing the flux and torque variations function the current and rotor position, fetched from the FEA model of the machine. The program created this way offers the possibility of fast simulation of the machine and allows in the same time the possibility of implementing several control procedures.
    EUROCON, 2013 IEEE; 01/2013
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    ABSTRACT: A modular stator switched reluctance motor (SRM) for fault tolerant drive systems is proposed. Owing to the particular construction of the stator there is no mutual coupling between adjacent phases. Hence, the motor can work also when a part of the coils is faulted and the faulted modules can be replaced without uncoupling the machine from the load or gearbox. The sizing particularities are presented and the mathematical model of the motor is developed. The results obtained via finite element analysis are compared with the analytical ones, and with that resulting after testing the constructed laboratory model. All these prove that the proposed SRM can be used in safety-critical drives.
    IET Electric Power Applications 01/2013; 7(3):159-169. · 1.56 Impact Factor
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    ABSTRACT: In advanced manufacturing systems complex movements are frequently needed. These can be performed by motion systems able to execute motion of several degrees of freedom. Usually each type of movement is performed by one independent electrical machine. In a more developed approach electrical machines able to perform more degrees of freedom motion are widely required. In the paper some contributions to two degrees of freedom modular variable reluctance motors are presented. Two typical machines able to perform such motion are discussed: a planar motor and a rotary-linear one.
    01/2012;
  • Electrical and Power Engineering Frontier. 01/2012; 1(1):1-7.
  • L. Szabó, M. Ruba
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    ABSTRACT: In safety-critical systems, faults can cause life losses, environmental degradation, or significant financial losses. In this paper, a segmental stator switched reluctance machine is proposed for such applications. A short overview of its design is given. Its fault tolerance is investigated by dynamic simulations and laboratory tests. It is demonstrated via both methods that the proposed machine is able to have a continuous operation despite five severe winding fault conditions.
    IEEE Transactions on Industry Applications 01/2012; 48(6):2223-2229. · 1.67 Impact Factor
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    I. Bentia, L. Szabo, M. Ruba
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    ABSTRACT: In the paper a switched reluctance rotary-linear motor is proposed and investigated. It is mechanically robust, simple to construct and easy to operate also in hostile industrial and automotive environment. The stator is built up modularly from correctly shifted three usual 8 poles switched reluctance motor stators. The mover is constructed of several common 6 poles SRM rotor stacks. The motor is able to ensure both rotating and linear movement. Its complex structure is analyzed in depth by means of finite element method based three dimensional numeric field computations. The proposed rotary-linear motor is expected to be useful in diverse advanced industrial and automotive applications where both linear and rotary motion is required and the space at disposal is reduced.
    Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2012 International Symposium on; 01/2012
  • M. Ruba, D. Fodorean
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    ABSTRACT: The use of electrical drives and machines with very high number of phases is not a common topic of researchers, because of the control difficulties and the important number of switches needed to assure the operation in faulty conditions. The advantage of using a high number of legs/phases provides smooth mechanical performances (i.e., reduced torque ripples), without increasing the number of poles (this last approach, is usually applied for fractional-slot machines, increases frequency, and consequently the iron loss). The authors are proposing a nine-phase drive to supply a permanent magnet synchronous machine. A prototype of nine-phase drive machine is constructed. Its capability to operate in faulty conditions will be evaluated by numerical computation and tests. It will be proved that the proposed solution can operated even in the most severe faulted conditions (78% of the drive machine being faulted).
    IEEE Transactions on Industry Applications 01/2012; 48(6):2092-2101. · 1.67 Impact Factor
  • M. Ruba, L. Szabo, D. Fodorean
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    ABSTRACT: The paper deals with the design and analysis of a low voltage high current switched reluctance machine used for small automotive applications. The design procedure is based on a numerical algorithm, validated later in simulations and measurements. The idea of the paper is based on designing a switched reluctance machine (SRM) used for driving a wheel chair for people with physical disabilities. The problem with such structures, involves a compromise between the maximum saturation of the core and its cooling, also taken into account the variation of the inductance with position when computing the firing angles. As the SRM has consistent torque ripples, different smoothing strategies need to be applied to the control of the machine's inverter in order to obtain a developed torque that ensures comfort for the wheel chair's driver.
    Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2012 International Symposium on; 01/2012
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    L. Szabo, I. Bentia, M. Ruba
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    ABSTRACT: In the paper a rotary-linear switched reluctance motor is proposed and investigated by means of advanced numerical simulations. The motor can generate two degrees of freedom movements: the same axis can both rotate and displace linearly. It is mechanically robust, simple to construct and easy to operate also in hostile automotive environment. The stator is built up modularly from precisely shifted three usual 8 poles switched reluctance motor stators and the rotor of several common 12 poles rotor stacks of the same machine. The complex structure of the motor is analyzed in depth by means of numeric field computations based on the finite element method analysis. The proposed rotary-linear motor machine is expected to be useful in diverse advanced automotive applications where both linear and rotary motion is required and the space at disposal is reduced.
    Electrical Machines (ICEM), 2012 XXth International Conference on; 01/2012
  • L. Szabo, I. Bentia, M. Ruba
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    ABSTRACT: A special switched reluctance motor able to perform both rotary and linear motion is proposed. Due to its compact and reliable construction and to its simple control it could be used in diverse dual motion industrial applications. In the paper the construction, working principle and design of the proposed machine are detailed. Its performances are studied by means of finite elements method based numeric field analyzes and of dynamic simulations.
    Optimization of Electrical and Electronic Equipment (OPTIM), 2012 13th International Conference on; 01/2012
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    ABSTRACT: Simulations are widely used in the study of both electrical machines and drives. In the literature, several simulation approaches can be found which can be also applied in the study of the switched reluctance motors (SRMs). The on-line SRM simulation tool developed by the authors and presented in this paper proved to be very useful both in checking the design of the motor, but also in setting up and verifying the proper control strategy of the motor. The simulation program can be very practical in teaching electrical machines and drives, and it can be extended to be used also in remote laboratories.
    Proceedings of the 25th European Conference on Modelling and Simulation (ECMS '2011), Krakow (Poland); 06/2011
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    ABSTRACT: In the paper a short overview is performed regarding the most frequently faults of the SRMs and the fault detectors cited in literature. By means of advanced numeric field computations the effects of faults on the machine's performances are analyzed and also the effectiveness of the detection circuits are taken into study. In the last part of the paper the dynamic behavior of the SRM will be investigated under several stator winding fault conditions.
    01/2011;
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    ABSTRACT: The switched reluctance machine (SRM) is considered as one of the most inherently fault tolerant electrical machines. Unfortunately despite its robustness and reliability, faults (mainly of its windings and bearings) can appear during its operation. Therefore the SRM's condition monitoring is very important mainly in those safety-critical applications where unwanted shutdowns could have catastrophic effects both on human life and costs. The paper deals with the winding faults of the SRMs and their detection. The effects of winding faults are investigated in details by means of advanced numeric field analysis based on the finite element method (FEM). This numerical method is widely used in electrical engineering to solve complex electromagnetic problems. In the last part of the paper also the effectiveness of the flux differential winding fault detector is taken into study.
    Computational Intelligence and Intelligent Informatics (ISCIII), 2011 5th International Symposium on; 01/2011
  • I. Bentia, M. Ruba, L. Szabo
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    ABSTRACT: In several advanced industrial applications both rotary and linear movements are required. But in many cases, mainly due to space limitations it is difficult to use two motors to ensure the two types of motion. For such applications the rotary-linear motors are ideal solutions. The proposed switched reluctance rotary-linear motor practically combines three identical rotating motors with a linear one. It can be used in precise two degrees of freedom motion control systems, as pick and place equipment, robotics, instrumentation, automotive applications, etc. In the first part of the paper the proposed motor is described together with its control system. In the second part results of simulations are given for the rotational, translational and combined rotating-linear movements. All these results emphasize the correct design of the motor and its capability to perform both the two types of movements.
    Computational Intelligence and Intelligent Informatics (ISCIII), 2011 5th International Symposium on; 01/2011
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    ABSTRACT: The paper deals with the fault tolerant analysis of several permanent magnet synchronous machines (PMSM) used in hybrid automobiles. There will be treated 3 distinctive elements: the electrical traction, the starter/generator and the steering system. By means of numerical analysis and through experiments, three different types of PMSM and their drives will be verified, while the fault tolerant concept is employed and verified.
    Electrical Machines (ICEM), 2010 XIX International Conference on; 10/2010
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    M. Ruba, I. Bentia, L. Szabo
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    ABSTRACT: Electrical machines and drives used in various safety-critical applications are of special design in order to achieve the required fault tolerance level. In the paper a novel modular fault tolerant switched reluctance machine is proposed and studied. It is proved by means of dynamic simulations that the proposed machine is able to have continuous operation also despite of five severe winding fault conditions.
    Electrical Machines (ICEM), 2010 XIX International Conference on; 10/2010