Monthly Archives: December 2015

Predictive versus Classic Control of the Induction Motor Drives

Abstract 

The paper deals with techniques which use the
predictive concepts in order to obtain both the pulse width
modulation strategy of a voltage fed inverter and the predictive
control of the induction motor drive. Concerning the
PWM technique, it is applied for the case when the inverter
supplies an induction motor, the reference values of the currents
being obtained from a classical vector control scheme.
The described technique is then simulated and the waveforms
are compared with ones obtained with preset currents
(bang-bang) pulse width modulation, as the behavior of the
two strategies is similar. The results are also compared with
the ones resulted when a classical DTC controls the induction
motor, as the both determine, during each sampling
period, the next stator voltage phasor, but considering different
criteria. Concerning the control of the drive, the vector
control and the predictive control of the induction motor
are compared. For the vector control, the rotor flux oriented
one is pointed out, with highlight on the voltage source inverter
type. A simple (and practical) method for avoiding
the influences of the stator resistance variations when a
voltage source inverter is used is presented, based on proper
simulation models. For the predictive control of the induction
motor, a sensorless diagram is considered. Finally, further
actions are proposed for the work continuation.
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Control circuit of an Electronically Controlled Capacitor for the Optimization of the Single Phase Induction Motor

Abstract

The control circuit of an Electronically Controlled Capacitor (ECC) for the optimization of the Single Phase Induction Motor (SPIM) with auxiliary winding is presented. The control circuit is based on a fixed value AC capacitor within a full bidirectional switches bridge PWM controlled at much higher than line frequency (in kHz range). The power bridge circuit and its embedded pulse driver circuit are presented within the theoretical sections of the paper. In the experimental section, using a small electric motors test bench and a two speed SPIM with auxiliary winding, are analyzed the main influences of the pulse drive circuit over the ECC. Firstly, being considered that the optimum is reached at the maximum motor torque, the optimal pulses frequency has been established around 4 kHz. Secondly, the switches over-voltages at the ommutations
moments being a serious drawback of the ECC, are analyzed the influence of the fixed capacitor value and the dead time of the pulse shape over the MOS-FET power transistors
of the bidirectional switches over-voltages. The overvoltages diminish as both the capacitor value and the dead time diminish. More than that, in contrast with some authors, there are no disadvantages as dead time became zero. These issues are the main contributions of this paper.
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Modelling of Transformer Windings and Computation of Very Fast Transient Over-Voltages

Abstract

The main objective of this paper is represented by analysis and modeling of the transformer windings stressed by over-voltage with direct impact on voltage distribution
across the winding. The authors considered both approaches in modeling the winding: windings with distributed electrical parameters respectively composed from disk coils with concentrated parameters. Both types of voltages applied across the transformer winding will generate free oscillations which are analyzed further on.
According to the model, the transformer’s windings are divided in several disk coils with concentrated known parameters. This results in a complete electrical network used for simulations. All simulations have been performed using the software package SYSEG (SYmbolic State Equation Generation).
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Annals Of The University Of Craiova, Serie: Electrical Engineering 2015

Content

Modelling of Transformer Windings and Computation of Very Fast Transient Over-Voltages – Gloria Ciumbulea, Sorin Deleanu, Mihai Iordache, Ciprian Curteanu, Neculai Galan, Anton Anastasie Moscu

Control circuit of an Electronically Controlled Capacitor for the Optimization of the Single Phase Induction Motor – Radu Câmpeanu, Adrian Danila

Predictive versus Classic Control of the Induction Motor Drives – Sergiu Ivanov, Vladimir Răsvan, Eugen Bobaşu, Dan Popescu, Florin Stîngă, Virginia Ivanov

Analytical-Numerical Method for Design of a Single-Phase AC Inductors with Ferromagnetic Core – Ioan Popa, Alin-Iulian Dolan, Florian Ştefănescu, Constantin Florin Ocoleanu

Optimal Heating Time for Cylindrical Items Removal from the Shaft – Grigore A. Cividjian

Analytical Algorithms for Synthesis of Modal Controllers by the Maximum Stability Degree Criterion – Ion Fiodorov, Bartolomeu Izvoreanu, Irina Cojuhari, Dumitru Moraru

Analysis of a Step-Down DC-DC Converter: Linear Versus Nonlinear Circuit – Ioana-Gabriela Sîrbu, Marius Voinea, Mihai Iordache

Designing a Simultaneous Control of Several Motors with a VHL Programming Language for a Single Microcontroller – Dan Mihai

Hardware Experiments for Simultaneous Control of Several Motors by a Microcontroller and a VHL Programming Language – Dan Mihai

Study of Low Power Alternating Current Motors by Functional and Energy Aspect – Ion Vlad, Aurel Campeanu, Sorin Enache, Monica-Adela Enache

Performance of an Active DC-Traction Substation with 12-Pulse Parallel Rectifier and Indirect Current Control – Mihaela Popescu, Alexandru Bitoleanu, Alexandra Preda

The Online Temperature Control – Florin Ravigan, Niculae Boteanu, Laurenţiu Alboteanu

Numerical Determination of Inductance of a SMES Device Using the Response Surface Methodology Applied on FEM Modeling – Alin-Iulian Dolan, Florian Stefanescu

Hybrid Petri Nets in Modeling the Packing Processes: Case Study – Mircea Adrian Drighiciu, Daniel Cristian Cismaru

Electromagnetic Field Coupling Between Over-Head Power Lines and Nearby Metallic Pipelines in Case of Direct Lightning – Denisa Stet, Levente Czumbil, Dan D. Micu

Modern Techniques for Monitoring Circuit Breakers by using Microcontroller System – Virginia Ivanov, Maria Brojboiu, Sergiu Ivanov

About the Analytical Methods Applying for Fault Diagnosis of the Static Converters from the Electric Locomotive – Maria Brojboiu, Ivanov Virginia, Andrei Savescu

Aspects Regarding Influences of Voltage and Resistant Torque on Asynchronous Motors Operation – Sorin Enache, Aurel Campeanu, Ion Vlad, Monica-Adela Enache

Lead Acid Battery Pack Charging Optimization – Constantin-Daniel Oancea, Florin Călin

Management of Renewable Energy Sources Integrated in a Micro Smart Grid – Laurenţiu Alboteanu, Gheorghe Manolea, Sergiu Ivanov

Factors Involved in Choosing LEDs for General Lighting Applications: a Critical Review – Dorin Dumitru Lucache, Cătălin Daniel Gălăţanu, Elena Dănilă

Transversal Shape Optimization of a Brushless DC Motor for Electric Vehicles – Ion Vlad, Sorin Enache, Lucian Mandache, Monica-Adela Enache

Information and Communication Technology in Urban Electric Transportation – Ilie Nucă, Iurie Nucă, Alexandr Motroi, Vitalie Eşanu

Study of Indirect Current Control Methods for Urban Traction Active DC Substations – Constantin Vlad Suru, Mihaela Popescu, Ionut Deaconu

Energetic Influence of Motor Power in Drive Systems with Space-Vector Static Converters and Induction Motors – Mihăiţă Lincă, Constantin Vlad Suru, Alexandru Bogdan Lupu

Increasing Safety of the Tests Carried Out in Laboratories by Using Electronic Devices – Marinel Popescu

Virtual Synchronoscope for Connecting Synchronous Generator on the Grid – Gheorghe-Eugen Subtirelu, Mircea Dobriceanu, Monica-Adela Enache

Use of Modern Computing Technique to Improve the Energy Indicators of Drive Motors of the Coal Mills – Silvia-Maria Digă, Daniela Popescu, Nicolae Digă

Estimation of the Heat Cumulated Inside a Wall with Cylindrical Symmetry – Mitică Iustinian Neacă, Andreea Maria Neacă

Fuzzy Control of Centrifugal Pumps Flow – Daniela Popescu, Jenica-Ileana Corcău

Object Oriented Video Retrieval System based on Domain Ontologies – Ion Eugen Ganea

Evolution of the Electric Power Components Definitions – Adrian A. Adăscăliţei, Alexander E. Emanuel

Active Power Filter Study Using Dedicated Matlab GUI – Cristina Alexandra Preda, Mihăiţă Lincă, Constantin Vlad Suru