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1

The effect of closed loop control on diagnostic indices in different faults of squirrel cage induction motor

Bouabid Nourelhouda, Moussa Mohamed-Amine, Maouche Yassine, Khezzar Abdelmalek

Archives of Electrical Engineering

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2021

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Vol. 70, nr 4

943--958

EN

The aim of this work is to study the influence of closed loop control on diagnostic indices of both broken bar and mixed air-gap eccentricity fault indices of the squirrel cage induction motor drive. The present work is focused on the direct stator current isd signal analysis, which is independent of torque load when the induction motor is controlled by an indirect control field. The fault signatures are on the line extracted from the direct stator current signal using the discrete Fourier transformation (DFT). The formula of the measured direct stator current at both conditions is determined by the transfer function of the current loop. The obtained results show that the current loop corresponds to a low pass filter and can reduce the magnitude of diagnostic indicators which lead to wrong evaluation of the fault. Simulation and experiments were carried out in order to confirm the theoretical analysis.

2

Design of dimmable light emitting diode driver for low power applications

Reddy U. Ramanjaneya, Koppolu Kalyan Kumar

Journal of Power Technologies

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2019

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Vol. 99, nr 3

204--209

EN

High-brightness light emitting diodes (HB-LED) are used in various applications in preference to conventional light bulbs due to following merits: eco-friendly nature, high luminous efficacy, prolonged life, compactness and low heat dissipation. This work presents the boost converter fed dimmable light emitting diode where illumination control is required. The proposed work uses pulse width modulated (PWM) controlled switch in series with LED load to control the illumination level by adjusting the pulse width. The closed loop control is designed in Matlab/Simulink to regulate the load voltage. This paper first illustrates in detail the basic operation of the converter and dimming control and then provides the simulation results with different illumination levels to demonstrate the effectiveness of converter and controller.

3

Control of a Finite Element Based Dynamic System

Marcsa D., Kuczmann M.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 12

155-158

EN

This paper presents the formulation of the circuit-coupled finite element method embedded in closed loop control system. The controller checks the output of the dynamic system after each time step and controls the input (current or voltage) to reach the steady state faster. The analysed dynamic systems are a voltage fed solenoid with iron core, and a three phase switched reluctance motor. The results of the voltage driven solenoid are compared with the results from the analytical model. The control parameters for the proportional-integral-derivative controller were estimated using the step response of the solenoid. The controller of switched reluctance motor is a speed and position based control logic.

PL

W artykule zaprezentowano sformułowanie sprzężone obwodowo-elementowoskończeniowe wykorzystanoe w systemie sterowania z zamkniętą pętlą. Kontroler sprawdza wyjście z systemu dynamicznego po każdym kroku czasowym i steruje wejście (prąd lub napięcie) w celu szybszego dojścia do stanu ustalonego. Analizowane systemy dynamiczne są napięciowo zasilanymi solenoidami z rdzeniem żelaznym w połączeniu z trójfazowym przełączalnym silnikiem reluktancyjnym. Wyniki otrzymane dla układu napędowego porównane zostały z wynikami otrzymanymi w modelu analitycznym. Parametry sterowania sterownika różniczkowo-całkowego zostały estymowane za pomocą analizy skokowej odpowiedzi solenoidu. Sterownik silnika reluktancyjnego przełączalnego bazuje na logice sterowania szybkości i położenia.

4

Optimum control of fluidised bed dryer by electrical capacitance tomography. Part 2: Control strategy and results

Wang H. G., Senior P., Mann R., Yang W. Q.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2009

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z. 114

29-33

EN

This paper presents closed-loop control of a fluidised bed drying process based on online moisture measurement by ECT. In this Part, the control strategy is discussed and some results from batch drying processes are given and compared with no feedback control. The fluidisation velocity is estimated by a semi-empirical function based on the measured water content and the information is sent to a controller to adjust the air flow rate of the fluidised bed. To evaluate the drying process, the thermal efficiency is given and results are compared based on this parameter.

5

Process monitoring and closed loop controlled process

Neugebauer R., Bräunlich H., Scheffler S.

Archives of Civil and Mechanical Engineering

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2009

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Vol. 9, no 2

105-126

EN

There are a number of variables which can seriously affect the sheet metal forming process. By determining the process fluctuations, it will ultimately be possible to improve the production process. To do this, monitored or closed loop controlled processes potentially constitute an important tool for the reduction of defects, reduction of rework and a better quality of final products. The Fraunhofer Institute for Machine Tools and Forming Technology (IWU) in Chemnitz investigated typical process variables such as flange movement as the basis for control systems. Different kinds of non-contact sensors were successfully tested. A multi-point cushion or tool integrated piezo-elements in conjunction with torsion-elastic tools were used as reacting systems. One application used process monitoring with one or more sensors to support quality control, or the same system with an add-on for early error recognition and automatic recommendation of corrective measures. Finally, fully controlled loop systems based on intelligent algorithms were developed.

PL

Istnieje pewna liczba czynników, które mogą poważnie wpłynąć na proces kształtowania blach. Poprzez określenie zmienności procesu staje się możliwe poprawienie procesu produkcji. W tym celu monitorowanie lub sterownie procesami poprzez sprzężenie zwrotne stanowi ważne narzędzie pozwalające na redukcję wad, zmniejszenie ilości poprawek i lepszą jakość końcowych produktów. Fraunhofer Institute for Machine Tools and Forming Technology (IWU) w Chemnitz zbadał typowe zmienne procesu, takie jak np. przemieszczenie kołnierza jako podstawę dla systemów kontroli. Różne rodzaje bezkontaktowych sensorów zostały z powodzeniem przetestowane. Wielopunktowa poduszka lub zintegrowane piezoelementy w połączeniu z narzędziami skrętno-sprężystymi zostały użyte jako systemy reagujące. Kompletny system kontroli opartym na inteligentnych algorytmach został opracowany.