1,721,061 research outputs found
Comparison between Permanent Magnet Assisted Synchronous Reluctance Motors Considering Electric Vehicle Driving Cycle
No full textPermanent magnet assisted synchronous reluctance motors are becoming a promising solution for electric vehicles, thanks to their high power density, efficiency and increased constant power speed range. The design of the rotor geometry, in terms of amount of PM to be inserted within the machine rotor slots, constitutes a challenging task which has to considered the requirements in terms of speed and torque during a typical electric vehicle driving cycle. This paper presents a comparison among different permanent magnet assisted synchronous reluctance motors for electric vehicles, by also investigating the influence of the number of pole pairs on the main performance indicators. The selected machines are therefore compared in terms of overall efficiency and operating limits, thus leading to some design insights for a given outer envelope
Stimatore Neurale dello Stato di un Motore ad Induzione
No full textNel presente lavoro si propone l'applicazione di uno stimatore neurale dello stato di un motore ad induzione. In particolare l'osservatore proposto è in grado di fornire stime sufficientemente accurate
delle componenti del flusso di statore o di rotore. Tali stime possono essere usate per effettuare il controllo vettoriale di un motore ad induzione. Lo stimatore è costituito da una rete neurale con un solo strato nascosto contenente cinque neuroni con funzioni sigmoidali. Esso è di tipo ricorrente, cioè utilizza i due stati stimati al passo n come ingressi per le stime al passo successivo. Gli altri
ingressi sono le componenti alfa-beta delle tensioni e correnti di statore. I risultati delle simulazioni
hanno mostrato l'efficacia dello stimatore neurale proposto quando l'addestramento delle rete è
effettuato utilizzando un algoritmo di apprendimento basato sulla teoria del filtro di Kalman estesa
Precise position control of tubular linear motors with neural networks and composite learning
No full textThis paper examines an adaptive control scheme for tubular linear motors with micro-metric positioning tolerances. Uncertainties such as friction and other electro-magnetic phenomena are approximated with a radial basis function neural network, which is trained online using a learning law based on Lyapunov design. Differently from related literature, the approximator is trained using a composite adaptation law combining the tracking error and the model prediction error. Stability analysis and bounds for both errors are established, and an extensive experimental investigation is performed to assess the practical advantages of the proposed scheme. (C) 2010 Elsevier Ltd. All rights reserved
Mechanical Refinements for the Stress Reduction of High-Speed Synchronous Reluctance Machines
No full textDesign methodologies for the output power maximisation of synchronous reluctance machines
Full text linkSynchronous reluctance (SyR) machines can constitute a promising alternative to permanent magnet machines for low-cost applications. The recent literature reports some guidelines for choosing the proper number and position of the rotor flux barriers capable of enhancing the electromagnetic performance in low-speed applications. However, as the rotational speed increases, the electromagnetic and structural mutual interactions become relevant; therefore, an optimal design requires a proper trade-off between torque production and stress reduction, which can be difficultly predicted analytically. This work proposes an approach based on optimisation algorithms in order to find ‘non-conventional’ geometries able to improve the power density: genetic algorithms coupled to magneto-static finite elements analysis and structural analytical models, are adopted to co-design SyR machines with different numbers of stator slots and rotor barriers subjected to the same thermal constraints. This study investigates two design procedures aimed at maximising the output power of SyR machines by increasing the rotational speed. Both procedures allow determining the power limits for a given volume of active parts and a fixed amount of admissible losses; moreover, the second procedure automatically finds also the rotational speed which maximises the output power
Dynamic-performance comparison of IRFO and SFO-SM controlled drives in field-weakening region using variable-saturation regulators
No full textThis paper proposes to use variable-saturation regulators for induction motor drives operating in field-weakening region, and presents a comparative dynamic-performance analysis between the traditional Indirect Rotor Field Oriented (IRFO) control scheme and a new Stator Flux Oriented - Sliding Mode (SFO-SM) control scheme. The traditional IRFO control scheme has the d-axis current component, torque, rotor flux, and speed loops with four PI-type controllers. The SFO-SM control system is a Direct Torque Control - Space Vector Modulation (DTC-SVM) scheme with closed loops of torque and stator flux without current PI-type controllers. Both control schemes use regulators with variable-saturation in such a way that maximum dc-bus voltage utilization is reached and overcurrent problems are prevented. The experiments are carried out using dSpace digital controllers and comparative results show that the SFO-SM controlled Induction Motor (IM) drive and IRFO one are characterized by similar dynamic responses in spite of structural simplicity of the SFO-SM control scheme
A New Approach to Sensorless Vector Control of SPMSM with Adaptive Sliding-Mode Observer
No full textThis paper presents a new approach to the sensorless vector control of Surface Permanent Magnet Synchronous Motor (SPMSM). It shows that the time-delay, in electrical rotor position estimation, does not influence the vector control when the d- and q-axis current components are accurately estimated. The PI controllers, fed by the actual d- and q-axis current errors, generate the correct voltage references in the estimated rotor reference frame. As a consequence, the coordinate transformation needs the estimated rotor position with no correction. To obtain accurate estimates of the d- and q-axis current components, it is sufficient that the estimated e.m.f. and current space vectors have the same delay as to the actual ones. An adaptive sliding-mode observer, with chattering-noise low-pass filter, is used to estimate the e.m.f. space vector, and a similar low-pass filter to delay the current space vector. The rotor speed and position are obtained from the estimated e.m.f. space vector and its derivative. Simulation results are presented to prove the effectiveness of the new approach to sensorless vector control
A new fuzzy logic-based controller design method for DC and AC impressed-voltage drives
No full textThis paper deals with the design of fuzzy logic-based controllers (FLBC) for de and ac electric drives. Industrial drives employ the cascaded PI control with a subordinated current control loop to make sure that the current does not exceed the admissible value and improve dynamic performances. The nonlinear FLBC characteristics permit one to achieve the performances of the cascaded control using only one control loop. This is feasible by a suitable choice of the scaling factors together with the rules of the fuzzy controller. The Authors propose a minimum number of rules and the criteria, based on physical considerations, to determine the input and output gains instead of using the trial and error procedure. The designed FLBC is able to control the speed of a de drive as well as the rotor speed and flux of a vector-controlled induction motor drive. Computer simulations show the effectiveness of the new fuzzy-controller design method. The reduced number of rules and membership functions and the application flexibility together with the possible implementation on low cost mu Ps let us think the proposed tuning criteria will be widely adopted
Experimental evaluation of current carrying capacity of printed circuit stator coils
No full textThis paper illustrates some results about the experimental characterization of current carrying capacity (CCC) of printed circuit board (PCB) stator coils. Thermometric tests have been carried out with both DC and AC power supply, in order to evaluate the relationship between flowing current and coils temperature rise and quantify with experiments the impact of frequency related parasitic phenomena on coils overheating. Temperature spatial distribution has been also investigated by means of thermal-imaging techniques. A comparison between experimental data and the most spread guideline for PCB traces sizing is provided
Optimal traces arrangement in planar magnetic based slotless PMSM
No full textThis paper presents an automated procedure for coils conductors’ arrangement. The procedure has been applied to slotless permanent magnet machines having planar magnetic stator windings, such as printed circuit board (PCB) coils. The proposed method is driven by optimization techniques whose goal is to find a proper arrangement of PCB traces, which make up stator windings in order to find some
trade-off solutions, optimal respect to some objective functions. A time-efficient numerical model has been developed to reduce computational load and thus make the optimization based
design attractive. The paper shows results of numerical simulations of an annular permanent magnet synchronous
machine having 200 poles and PCB windings
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