1,721,095 research outputs found
ESARS'12 - IEEE Conference on Electrical Systems for Aircraft, Railway and Ship Propulsion
No full textA Low Cost Resolver-to-Digital Converter
No full textIn this paper, the full implementation on a combined analog-digital board of the resolver-to-digital conversion is proposed. It represents a low cost solution for measuring the position by means of standard resolvers. Some experimental results are presented and a comparison with the performances achieved by means of an incremental encoder is performed
Adhesion-Recovery Control for Electrical Traction Drives
No full textThe Vectorial Torque Control algorithm is applied in order to impose the re-adhesion trajectory in an induction motor drive for traction purposes. It allows to achieve a very strong anti-skidding action assuring, at the same time, low stress for the mechanical parts. The efficacy of the proposed control strategy has been validated by an experiment. Several skid effects have been achieved by means of an high dynamic performance hysteresis brake assembled on the controlled motor shaft, which allows to impose any load torque profile. The results obtained by the experiment fully confirm the validity of the proposed control strategy
Optimized Modulation for PWM Rectifiers
No full textAn optimized set-up for controlling PWM rectifiers is proposed in this paper. In particular, the control part is based on a predictive estimation algorithm which guarantees the imposed value of the dc link output voltage and, at the same time, a unity power factor behavior at the mains. The modulation part consists on a digital space vector modulator, which eliminates the drop voltage due to the dead time effect and, also, avoids the current zero clamping phenomenon. The results achieved by means of an experiment confirm that improvements on the AC source current waveforms and controllable dc bus voltage are achieved with the proposed system
Hardware Dead Time Compensation for VSI Based Electrical Drives
No full textA full hardware modulator board for space vector modulation which allows the dead time effects compensation is presented in this paper. It consists of a
fully integrated digital set-up implemented on a programmable logic device. It is based on an adequate modification of the switching sequence generation on the base of the phase stator current signs and of the power modules status. In the paper, a detailed description of the modulator set-up will be provided together with some experimental results
Field Oriented Control of Induction Motor by Means of a H_infinity Controller
No full textIn the paper, the H_infinity control theory is used in order to design a state feedback controller for field oriented speed control of induction motor. In particular, the problem of finding an optimal H_infinity controller has been considered. The performances ofthe proposed controller are numerically analyzed and experimentally verified. The results confirm that good dynamic performances and high robustness to variations of system's parameter can be achieved
A NEW QUASI-RESONANT DC LINK TOPOLOGY FOR SOFT SWITCHING OF VOLTAGE-SOURCE INVERTER
No full textPulsewidth modulated voltage source inverter can be easily controlled in such a way as to achieve the desired value of the output voltage and/or current, but they exhibit high switching losses when operated at high switching frequencies. Besides, relevant electromagnetic interferences can be produced because of the high di/dt and dv/dt in the converter waveforms. These problems can be partially or totally eliminated if the converter switches are commutated at zero voltage and or zero current. This is achieved by means of suitable tuned LC resonant circuits. In this paper, a novel topology of quasi-resonant dc link for soft switching of VSI is
proposed. It is based on two resonant circuits: a main one, which makes the voltage oscillating around the main dc bus voltage, and which is commutated at zero current, and an auxiliary circuit which is enabled to drive the dc voltage to zero just when an inverter switch commutation occurs. Dead time imposition is fully taken
into account. A detailed experiment investigation has been performed for validating the proposed scheme
Low Losses Modulation of PWM-Rectifier
No full textAn optimized modulation technique which is specific for PWM-rectifier is proposed in this paper. It is based on the imposition of modulation frequencies different for the three rectifier legs, selected according to the power modules commutation losses. A reduction of the current harmonic content and an improvement of the overall system performances are achieved, as shown by means of an experiment implementation
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