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ZSV Spectrum-Based Detection of IM Rotor Dissymmetry Immunity to False Alarms DOI:10.15199/48.2017.05.07

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This paper presents a comprehensive study of new tool used to detect rotor asymmetries in induction motors, which operate in different types of operating conditions and different loads. The proposed approach is performed by tracking the amplitude of the most sensitive harmonics in the spectrum of the line neutral voltage called also the Zero Sequence Voltage (potential difference between the null point of the supply voltage system and the neutral of the star connection of IM stator winding), using a dynamic acquisition rate based on machine frequency supply. To assess detection accuracy under the various severity levels of the faults, two supply conditions are investigated: (i) Motor supplied by network fed and (ii) Motor supplied by inverter fed. Results obtained from experimental tests are presented to validate the study. Streszczenie. W artykule opisano nowe narzędzie do wykrywania asymetrii wirnika w silniku indukcyjnym. W opisanej metodzie śledzone są wartości harmonicznych w napięciu Zero Sequence Voltage (różnicy między punktem zerowym zasilania I punktem zerowym uzwojenia stojana połączonego w gwiazdę. Wykrywanie asymetrii wirnika w silniku indukcyjnym na podstawie analizy napięcie ZSV Keywords: diagnosis; broken rotor fault; Zero Sequence Voltage; MCSA; Rotor Fault indicator. Słowa kluczowe: silnik indukcyjny, asymetria wirnika Introduction Induction motors (IM) are used in many industrial processes and are frequently integrated in commercially available equipment. Robustness, cost advantage, high power capabilities, and performance are the major concerns of IM applications. Although IM are reliable, they are subjected to some failures. Therefore, monitoring and diagnosing faults in IMs is a scientific and economic issue which is motivated by objectives for reliability and serviceability in electrical machines drives. There has been substantial amount of research to provide new condition monitoring techniques for induction mo[...]

Comparison of three estimators used in a sensorless MPPT strategy for a wind energy conversion chain based on a PMSG DOI:10.15199/48.2018.03.04

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Wind energy is one of the prominent renewable energy sources on earth. The global trend of recent research in this field is to minimize the overall cost of the Wind Energy Conversion System (WECS) while improving the quality of the produced power. With this aim, several works have been carried out to avoid the use of the mechanical sensors which are expensive to buy and maintain. The principal role of the sensors is measuring the generator rotation speed as well as the angle of the rotor that are necessary for the control of the system and the search of the maximum points of the extractable power. Reliability of the variable speed wind turbine can be improved significantly using a directdrive Permanent Magnet Synchrounous Generator (PMSG) [1]. A sensorless Maximum Power Point Tracking (MPPT) strategy is proposed to control the pre-mentioned structure, it consists of two levels; the first is a power regulation loop generating the reference value of current iqref to the Field Oriented Control (FOC) [2] justified by a power maximization analysis. The second level is the extremum seeking method [3] generating the optimum value of the coefficient including turbine parameters in the expression of the turbine output power. The main objective of this paper is to compare three types of estimators used to build the sensorless MPPT. The first estimator is an Angle Tracking observer (ATO) [4], the second is the Extended Kalman Filter (EKF) [5] and the third is the Synchronous Reference Frame Phase Locked Loop (SRF-PLL) [6]. The global wind conversion chain is presented in Fig.1. Simulation results obtained using Matlab-Simulink and allowing the comparison of the three estimators can be found at the end of this paper. In the conclusion we evaluate performance of the three estimators and give their basic advantages and disadvantages. Global system modeling The wind conversion chain considered in this work is presented in Fig.1 consis[...]

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