Sensorless Indirect Stator Field Orientation Speed Control for Single-Phase Induction Motor Drive

10International audienceThe industrial requirements for the control of an induction machine without a mechanical sensor continue to be of interest, as evidenced by the most recent publications. The focus is on improvements of control without a mechanical sensor. A new method for the implementation of a sensorless indirect stator-fluxoriented control (ISFOC) of a single-phase induction motor (SPIM) drive is proposed in this paper. The proposed method of rotor speed estimation is based only on themeasurement of themain and auxiliary windings stator currents and that of a reference q-axis current generated by the control algorithm. The error of the measured qaxis current from its reference value feeds the proportional plus integral controller, the output of which is the estimated slip angular frequency. Experimental results for sensorless ISFOC speed control of a SPIM drive are presented and analyzed using a dSPACE system with DS1104 controller board based on the digital signal processor TMS320F240. Digital simulation and experimental results are presented to show the improvement in performance of the proposed sensorless algorithm

Fault Tolerant Power Converter Topologies for Sensor-less Speed Control of PMSM Drives

This paper exhibits a sensor-less speed control method based MRAS observer applied to a fault-tolerant PMSM drive system. So, this paper proposes a rapid method of fault switch detection in the power converters aiming to make sure the continuity of service even though the fault presence of an opening phase. In fact, the MRAS observer is used to replace the mechanical sensor and a redundant inverter leg is equally employed to replace the faulty leg. The proposed fast fault diagnosis method has the features of simple algorithm, independence of the transient states and being simply integrated without any additional sensors

Функціональні зв'язки між ефектами води Нафтуся на канальцеву секреторно-транспортну та імунну системи щурів. Повідомлення 2: Канальцева секреція і параметри спленоцитограми та гемолімфоаденоцитограми

В рамках концепции об общности механизмов функционирования канальцевой секреторно-транспортной и фагоцитарно-лимфоидной систем выявлены существенные связи между скоростью почечной канальцевой секреции и параметрами фагоцитоза, лейкоцитограммы крови, стеноцитогаммы и гемолимфоаденоцитограммы крыс в условиях курсового напаивания их водой Нафтуся per se и в сочетании с цитостатиком или анаболиком.It is shown that increase of canalicular secretion in rats becaused by drinking of water Naftussya accompanied increase massa of haemolymphatic node and contents in its of endothelio-, reticulo-, lymphocytes, eosinophyles and macrophages, blood level lymphocytes, monocytes and segmental nucleare neutrophyles but decrease activity and completion of phagocytose of neutrophyles and level of lymphoblastes in splenocytogramme. The using of cytostatic drug abolishes but anabolic drug potentiates both activating and inhibiting influence of water Naftussya

Geographic distribution of MERS coronavirus among dromedary camels, Africa

We found serologic evidence for the circulation of Middle East respiratory syndrome coronavirus among dromedary camels in Nigeria, Tunisia, and Ethiopia. Circulation of the virus among dromedaries across broad areas of Africa may indicate that this disease is currently underdiagnosed in humans outside the Arabian Peninsula

Phage Therapy and Photodynamic Therapy: Low Environmental Impact Approaches to Inactivate Microorganisms in Fish Farming Plants

Owing to the increasing importance of aquaculture to compensate for the progressive worldwide reduction of natural fish and to the fact that several fish farming plants often suffer from heavy financial losses due to the development of infections caused by microbial pathogens, including multidrug resistant bacteria, more environmentally-friendly strategies to control fish infections are urgently needed to make the aquaculture industry more sustainable. The aim of this review is to briefly present the typical fish farming diseases and their threats and discuss the present state of chemotherapy to inactivate microorganisms in fish farming plants as well as to examine the new environmentally friendly approaches to control fish infection namely phage therapy and photodynamic antimicrobial therapy

MOLLUSCICIDAL AND LARVICIDAL ACTIVITIES OF Atriplex inflata AERIAL PARTS AGAINST THE MOLLUSK Galba truncatula, INTERMEDIATE HOST OF Fasciola hepatica

Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols

Sensorless Speed Control and High-Performance Fault Diagnosis in VSI-Fed PMSM Motor Drive Under Open-Phase Fault: Analysis and Experiments

International audienceThis paper aims to provide a high-performance sensorless fault-tolerant direct torque control of permanent magnet synchronous motor based on nonlinear position and speed observer. The nonlinear observer is based on a trigonometric function to estimate the rotor position, and a proportional–integral controller is used to estimate the speed from estimated position. A faulty leg (open phase) in the PWM VSI changes the corresponding terminal voltage and introduces the voltage distortions to each phase voltage. The ordinary two-level inverter is composed of three legs. In the proposed fault-tolerant inverter, a redundant leg is added that replaces the faulted leg. The detection of the open-phase fault is based only on the current signals and the maximum threshold they exceed that in case of fault

A Time-Varying Gain Super-Twisting Algorithm to Drive a SPIM

International audienc

Implementation of Improved Sliding Mode Observer and Fault Tolerant Control for a PMSM Drive

International audienceThis paper presents the development and experimentation of Fault-Tolerant Control (FTC) for sensorless Permanent Magnet Synchronous Motor (PMSM) drive with stator resistance tuning. In the fault-tolerant inverter, a redundant leg is added to replace the faulted leg. Consequently, the proposed inverter is a modified topology inverter with fault-tolerant capability, which can be configured as 3-phase 8-switch inverter. The detection of the faulty leg is based only on the output inverter currents measurement. To make toggle to a redundant leg in case of fault occurrence, a Fault Detection and Isolation (FDI) algorithm is proposed in this paper. Experimental results are presented using a 1.4kW, three poles three-phases PMSM. These results show that the proposed FDI algorithm is able to detect and to isolate the open-phase fault in PMSM drive

High performance sensorless speed vector control of SPIM Drives with on-line stator resistance estimation

International audienc