Active disturbance rejection control for four-wire inverters in standalone renewable resources-based microgrid - islanded microgrids ADRC-based control.

This paper presents an active disturbance rejection control (ADRC) approach for three-phase four-legs voltage source inverters (FL-VSIs) in a standalone renewable energy resources (RES)-based islanded microgrid. The key purpose of the proposed approach is to improve the control robustness against load-side disturbances, power supply parameters uncertainties, and faulty operating conditions. Indeed, a notable benefit of ADRC is its ability to operate effectively without the need for precise knowledge of disturbance characteristics or accurate modeling and FL-VSI parameters.

Design and analysis of virtual impedance control scheme based on MESOGI for improving harmonic sharing of nonlinear loads.

Under the presence of nonlinear load, the most existing virtual impedance (VI) methods-based control solution performs poorly in reactive power sharing among droop-operated VSIs in microgrids (MGs). This may be due to the involved estimation techniques for extracting the current harmonics at selected frequencies, which suffer from either poor accuracy of the harmonic estimation and/or the effect of DC offset in the measurements. Such an issue may affect the performance of the virtual impedance control, hence, the system stability.

Intramasseteric Solitary Myofibroma: A Case Report.

Solitary myofibroma or infantile myofibroma is a rare spindle cell neoplasm that generally affects infants before the age of 2 years but cases in young children and adults have been described. Although the location of infantile myofibroma in the oral and maxillofacial region has been described, the intramasseteric location of the lesion is very uncommon. A thorough assessment of histopathological and immunohistochemical characteristics is necessary to have a correct diagnosis.

Double voltage vector model predictive control for grid-connected cascade H-bridge multilevel inverter with fixed switching frequency.

Model predictive control (MPC) is an outstanding control method which can achieve superior dynamic response, nonlinear control and multi-objective collaborative control. However, because of unfixed switching frequency, the harmonic spectrum of the output current is dispersed, which would make it difficult to design the output filter. In this work, a double voltage vector model predictive control (DVV-MPC) algorithm for grid-connected cascade H-bridge (CHB) multilevel inverter is presented.

High-consistency proton exchange membrane fuel cells enabled by oxygen-electron mixed-pathway electrodes via digitalization design.

Proton exchange membrane (PEM) fuel cell has been regarded as a promising approach to the decarbonization and diversification of energy sources. In recent years, durability and cost issues of PEM fuel cells are increasingly significant with the rapid increase of power density. However, the failure to maintain the cell consistency, as one major cause of the above issue, has attracted little attention.

Hardware-in-the-loop implementation of an unknown input observer for synchronous reluctance motor.

In this paper, we design a proportional integral observe for a nonlinear synchronous reluctance motor described by a Takagi-Sugeno multi-model. In this design, both states and unknown inputs are estimated simultaneously. First, the mathematical nonlinear model of the synchronous reluctance motor is established, then it transformed into a Takagi-Sugeno exact form by a simple polytopic transformation.

Fundamental frequency sequence amplitude estimator for power and energy applications.

A grid-synchronization-based fundamental frequency positive-sequence (FFPS) and negative-sequence (FFNS) amplitudes estimation technique is proposed for unbalanced and distorted grid. In this technique, the sequence amplitudes are extracted by extracting the phase-angle of the FFPS and FFNS components. The extracted phase-angles have DC and double frequency AC components.

Exposing Deep Representations to a Recurrent Expansion with Multiple Repeats for Fuel Cells Time Series Prognosis.

The green conversion of proton exchange membrane fuel cells (PEMFCs) has received particular attention in both stationary and transportation applications. However, the poor durability of PEMFC represents a major problem that hampers its commercial application since dynamic operating conditions, including physical deterioration, have a serious impact on the cell performance. Under these circumstances, prognosis and health management (PHM) plays an important role in prolonging durability and preventing damage propagation via the accurate planning of a condition-based maintenance (CBM) schedule.

Gearbox Failure Diagnosis Using a Multisensor Data-Fusion Machine-Learning-Based Approach.

Failure detection and diagnosis are of crucial importance for the reliable and safe operation of industrial equipment and systems, while gearbox failures are one of the main factors leading to long-term downtime. Condition-based maintenance addresses this issue using several expert systems for early failure diagnosis to avoid unplanned shutdowns. In this context, this paper provides a comparative study of two machine-learning-based approaches for gearbox failure diagnosis.

Gradient Estimator-Based Amplitude Estimation for Dynamic Mode Atomic Force Microscopy: Small-Signal Modeling and Tuning.

Atomic force microscopy (AFM) plays an important role in nanoscale imaging application. AFM works by oscillating a microcantilever on the surface of the sample being scanned. In this process, estimating the amplitude of the cantilever deflection signal plays an important role in characterizing the topography of the surface.

About a rare disease misdiagnosed as malignant lymphoma or tuberculosis: Kikuchi-Fujimoto's disease.

Kikuchi-Fujimoto's disease KFD is a rare and benign cause of cervical lymphadenopathy. It is an anatomoclinical entity of unknown etiology. The confirmation of the diagnosis is always provided by histological lymph node study.

A new rooted tree optimization algorithm for indirect power control of wind turbine based on a doubly-fed induction generator.

A new control strategy based on the root tree optimization (RTO) is presented in order to reduce the chattering phenomena in active and reactive powers, and to minimize the harmonic currents which appear mostly at the level of the rotor side converter (RSC), in a doubly-fed induction generator (DFIG). The root tree optimization is used to adjust the parameters (K,K) of PI controller (RTO-PI). Simulation results are presented to demonstrate the effectiveness of the new proposed technique.

[Rhinoscleroma of the cavum with expression in cervical lymph nodes: about a case].

Rhinoscleroma is a specific granulomatous and chronic disorder with insidious evolution. It is causes by pathogen Klebsiella rhinoscleromatis. It mainly occurs in the nasal cavities and positive diagnosis is sometimes problematic.

[An unusual cause of high dysphagia: schwannoma of the preepiglottic space].

Schwannomas are well encapsulated mesenchymal tumors of peripheral nerves, with slow growth. The laryngeal schwanomma is exceptional, we present a case not described in the literature of shwannoma in the pre epiglottic space. A 50-year-old woman, who had a history of foreign body sensation for 4 years ago, progressing to high dysphagia and hoarseness.

An imbalance fault detection method based on data normalization and EMD for marine current turbines.

This paper proposes an imbalance fault detection method based on data normalization and Empirical Mode Decomposition (EMD) for variable speed direct-drive Marine Current Turbine (MCT) system. The method is based on the MCT stator current under the condition of wave and turbulence. The goal of this method is to extract blade imbalance fault feature, which is concealed by the supply frequency and the environment noise.

Load estimator-based hybrid controller design for two-interleaved boost converter dedicated to renewable energy and automotive applications.

This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller.

A case of Kartagener syndrome with rhinolalia clausa.

Kartagener syndrome is an autosomal recessive genetic ciliary disorder comprising of a classic triad of sinusitis, situs inversus and bronchiectasis. It's the one of primary ciliary dyskinesia disorders with manifestations present from childhood. Most patients of PCD have situs inversus.

Evaluation of Post Laryngectomy Pharyngocutaneous Fistula risk Factors.

Introduction: Pharyngocutaneous fistula (PCF) is the most common complication after total laryngectomy. Its incidence is extremely variable, with values ranging from 3% and 65%. The management of this problem considerably increases the length and the cost of hospitalization.

Induction machine bearing faults detection based on a multi-dimensional MUSIC algorithm and maximum likelihood estimation.

Condition monitoring of electric drives is of paramount importance since it contributes to enhance the system reliability and availability. Moreover, the knowledge about the fault mode behavior is extremely important in order to improve system protection and fault-tolerant control. Fault detection and diagnosis in squirrel cage induction machines based on motor current signature analysis (MCSA) has been widely investigated.

The use of SESK as a trend parameter for localized bearing fault diagnosis in induction machines.

A critical work of bearing fault diagnosis is locating the optimum frequency band that contains faulty bearing signal, which is usually buried in the noise background. Now, envelope analysis is commonly used to obtain the bearing defect harmonics from the envelope signal spectrum analysis and has shown fine results in identifying incipient failures occurring in the different parts of a bearing. However, the main step in implementing envelope analysis is to determine a frequency band that contains faulty bearing signal component with the highest signal noise level.

Sliding mode based fault detection, reconstruction and fault tolerant control scheme for motor systems.

The fault-tolerant control problem belongs to the domain of complex control systems in which inter-control-disciplinary information and expertise are required. This paper proposes an improved faults detection, reconstruction and fault-tolerant control (FTC) scheme for motor systems (MS) with typical faults. For this purpose, a sliding mode controller (SMC) with an integral sliding surface is adopted.

Second-order sliding mode control for DFIG-based wind turbines fault ride-through capability enhancement.

This paper deals with the fault ride-through capability assessment of a doubly fed induction generator-based wind turbine using a high-order sliding mode control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the fault ride-through problem. In this context, this paper proposes a second-order sliding mode as an improved solution that handle the classical sliding mode chattering problem.

[Removal of lateral orbital wall for management of orbital cavernous hemangioma].

Introduction: A relatively rare condition, cavernous hemangioma of the orbit poses a problem due to difficulty of the surgical approach. Modifications in surgical approaches and better understanding of these tumors preoperatively allow for less disfiguring elective surgery than before.

Materials And Methods: Five cases of orbital cavernous hemangiomas reviewed in our department between 2005 and 2009 underwent surgery by external lateral approach with removal of the lateral orbital wall.

Cervical lymph node metastasis in chromophobe renal cell carcinoma: a case report and review of the literature.

The metastasis of chromophobe renal cell carcinoma to head and neck region, described herein, has never been reported before to our knowledge. A 56-year-old woman with a history of nephrectomy, that revealed chromophobe renal cell carcinoma six years before, presented left cervical mass. Imaging showed with left cervical lymphadenopathies and thyroid nodule.