Advanced model of squirrel cage induction machine for broken rotor bars fault using multi indicators

Squirrel cage induction machine are the most commonly used electrical drives, but like any other machine, they are vulnerable to faults. Among the widespread failures of the induction machine there are rotor faults. This paper focuses on the detection of broken rotor bars fault using multi-indicator. However, diagnostics of asynchronous machine rotor faults can be accomplished by analysing the anomalies of machine local variable such as torque, magnetic flux, stator current and neutral voltage signature analysis. The aim of this research is to summarize the existing models and to develop new models of squirrel cage induction motors with consideration of the neutral voltage and to study the effect of broken rotor bars on the different electrical quantities such as the park currents, torque, stator currents and neutral voltage. The performance of the model was assessed by comparing the simulation and experimental results. The obtained results show the effectiveness of the model, and allow detection and diagnosis of these defects

Design of Compact Monopole Antenna using Double U-DMS Resonators for WLAN, LTE, and WiMAX Applications

This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexIn this research, a novel wide-band microstrip antenna for wideband applications is proposed. The proposed antenna consists of a square radiating patch and a partial ground plane with a smal rectangular notch-shape. Two symmetrical U-slots are etched in radiating patch. The defected microstrip U-shapes and the small notch improve the antenna characterestics such impedance wideband and the gain along the transmission area. The proposed antenna is simulated on an FR4 substrate of a dielectric constant of 4.3, thickness 1.6 mm, permittivity 4.4, and loss tangent 0.018. The simulation and optimization results are carried out using CST software.The antenna topology occupies an area of 30 × 40 × 0.8 mm3 or about 0.629λg × 0.839λg × 0.017λg at 3 GHz (the centerresonance frequency). The antenna covers the range of 2.1711 to 4.0531 GHz, which meet the requirements of the wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX) and LTE (Long Term Evolution) band applications. Good VSWR, return loss and radiation pattern characteristics are obtained in the frequency band of interest. The obtained Simulation results for this antenna depict that it exhibits good radiation behavior within the transmission frequency range

International Journal of Smart Grid and Clean Energy Maximum power tracking control wind turbine based on permanent magnet synchronous generator with complete converter

Abstract This paper discusses the problem of maximum power point tracking (MPPT) of Wind Turbine based on a permanent magnet synchronous generator (PMSG) connected to power grid trough complete static converter. To achieve this, we propose a control scheme of synchronous generator, consisting of a DC/AC device followed by a second DC/AC device. The idea behind MPPT principle is turbine speed variation depending on wind speed in case of generator indirect connection to power grid. Simulations on Matlab-Simulink can be found at the end of the paper, confirming a good consistency with study objectives of control scheme, selection of setting parameters and complete converter architecture

Modeling and Robust Control of a Grid Connected Direct Driven PMSG Wind Turbine By ADRC

In this paper, we present the modeling and control of a grid connected Variable Speed Wind Energy Conversion System (VS-WECS) based on a Direct Driven Permanent Magnet Synchronous Generator (DD-PMSG). A new robust control has been proposed and utilized to operate the wind turbine so as to extract the maximum power from the wind energy and to ensure a unit power factor. This control is known as the Active Disturbance Rejection Control (ADRC) and it is based on the Extended State Observer (ESO). It consists in controlling, through the stator currents, the machine side converter in order to adapt the rotational speed of the generator to the different wind speed profiles (Maximum Power Point Tracking MPPT). In addition, it ensures the control of the DC bus voltage and the exchange of active and reactive powers between the wind turbine and the electrical power grid. In order to evaluate the performance of the proposed control a series of simulations are made under the MATLAB/SIMULINK environment. The results obtained by simulation show that the proposed strategy is efficient in terms of stability and precision as well as for the robustness with regard to the internal disturbances when variying the parameters of the machine

A Compact Wideband Monopole Antenna using Single Open Loop Resonator for Wireless Communication Applications

A novel single layer, microstrip line fed compact wideband monopole antenna using open loop resonator has been designed and analyzed. The proposed antenna occupies a compact size of only 30 36.5 1.6 mm3. A partial ground plane is employed to enhance the operating bandwidth and reflection coefficient of the proposed antenna. The variations in operating bandwidth of the proposed antenna can be easily controlled by properly adjusting the position of the gap in the open loop resonator.The antenna prototype is fabricated on FR4 substrate with a dielectric constant 4.2. In this design, the antenna exhibits 10dB wide impedance bandwidth of 61% from 2.0174 to 3.7903 GHz.The antenna can be easily fed using a 50 Ω microstrip feed line and it covers the bandwidth requirements of a number of modern wireless communication systems such as IEEE 502.11b WLAN band (2.4 2.5 GHz), extended UMTS (2.5 2.69 GHz), IMT (2.7 2.9 GHz), and IEEE 802.16 Wi MAX band (3.3 3.6 GHz) applications. The desired antenna is designed and simulated using Computer Simulation Technology (CST). An extensive analysis of the antenna parameters (reflection coefficient, radiation pattern, directivity, and VSWR) including surface current distributions is presented and discussed in this paper. Good agreement between simulated and measured result is obtained

Reliable detection of rotor faults in IM using frequency tracking and Zero Sequence Voltage

The AC Alternating Current Induction Motor (IM) is the most commonly used AC motor in industrial applications because of its simplicity, robust construction, and relatively low manufacturing costs. To avoid expensive repairs in IM, early faults detection is needed. In this context, this paper presents a novel approach used to detect rotor asymmetries in induction motors. The Zero Sequence Voltage (ZSV) defined as the potential difference between the null point of the supply voltage system and the neutral of the star connection of IM stator winding is measured and employed for tracking the amplitude of the most sensitive harmonics in the spectrum of ZSV. This detection leads to make a criterion to take a decision about the state of the machine without a Prior knowledge. Simulation and experimental results obtained from real tests are presented to validate the study

Intelligent Bearing Fault Diagnosis Method Based on HNR Envelope and Classification Using Supervised Machine Learning Algorithms

Research on data-driven bearing fault diagnosis techniques has recently drawn more and more attention due to the availability of massive condition monitoring data. The research work presented in this paper aims to develop an architecture for the detection and diagnosis of bearing faults in the induction machines. The developed data-oriented architecture uses vibration signals collected by sensors placed on the machine, which is based, in the first place, on the extraction of fault indicators based on the harmonics-to-noise ratio envelope. Normalisation is then applied to the extracted indicators to create a well-processed data set. The evolution of these indicators will be studied afterwards according to the type and severity of defects using sequential backward selection technique. Supervised machine learning classification methods are developed to classify the measurements described by the feature vector with respect to the known modes of operation. In the last phase concerning decision making, ten classifiers are tested and applied based on the selected and combined indicators. The developed classification methods allow classifying the observations, with respect to the different modes of bearing condition (outer race, inner race fault or healthy condition). The proposed method is validated on data collected using an experimental bearing test bench. The experimental results indicate that the proposed architecture achieves high accuracy in bearing fault detection under all operational conditions. The results show that, compared to some proposed approaches, our proposed architecture can achieve better performance overall in terms of the number of optimal features and the accuracy of the tests

Wireless health monitoring system for rotor eccentricity faults detection in induction machine

Condition monitoring and fault detection of induction machines become an important area of research. Many techniques have been applied in this field including vibration, thermal, chemical and acoustic emission monitoring, but Motor Current Signature Analysis monitoring techniques usually are applied to detect the various classes of induction machine faults such as rotor, short winding, eccentricity and bearing fault etc. This paper presents a wireless system detection for rotor eccentricity faults in induction machine based on LabVIEW platform. Moreover, it is demonstrated that eccentricity fault generates a series of low frequency components in the form of sidebands around the fundamental frequency and its harmonic. In addition, the amplitudes of those components increase in proportion to the load and fault severity. The Power Spectral Density techniques and Short Time Frequency Transform spectrogram of current signals are used to detect the presence of those fault signatures

A two-level sensorless MPPT strategy using SRF-PLL on a PMSG wind energy conversion system

In this paper, a two-level sensorless Maximum Power Point Tracking (MPPT) strategy is presented for a variable speed Wind Energy Conversion System (WECS). The proposed system is composed of a wind turbine, a direct-drive Permanent Magnet Synchronous Generator (PMSG) and a three phase controlled rectifier connected to a DC load. The realised generator output power maximization analysis justifies the use of the Field Oriented Control (FOC) giving the six Pulse Width Modulation (PWM) signals to the active rectifier. The generator rotor speed and position required by the FOC and the sensorless MPPT are estimated using a Synchronous Reference Frame Phase Locked Loop (SRF-PLL). The MPPT strategy used consists of two levels, the first level is a power regulation loop and the second level is an extremum seeking bloc generating the coefficient gathering the turbine characteristics. Experimental results validated on a hardware test setup using a DSP digital board (dSPACE 1104) are presented. Figures illustrating the estimated speed and angle confirm that the SRF-PLL is able to give an estimated speed and angle which closely follow the real ones. Also, the power at the DC load and the power at the generator output indicate that the MPPT gives optimum extracted power. Finally, other results show the effectiveness of the adopted approach in real time applications