EPE Journal Volume 20-1 
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EPE Journal Volume 20-1 - Editorial
EPE Journal Volume 20-1 - Papers
EPE Journal Volume 20-1: Other



 EPE Journal Volume 20-1 - Editorial 

Invitation to EPE-PEMC 2010 in Ohrid (Republic of Macedonia)  [Details]
By Slobodan Mircevski; Dushan Boroyevich
Invitation to EPE-PEMC 2010 in Ohrid (Republic of Macedonia), the 14th International Power Electronics and Motion Control Conference, September 6-8, 2010, written by Slobodan Mircevski and Dushan Boroyevich


 EPE Journal Volume 20-1 - Papers 

Two Different Schemes for Three-level Voltage Space Vector Generation for Induction Motor drives with Reduced DC-Link Voltage  [Details]
By K. Sivakumar; Anandarup Das; Rijil Ramchand; Chintan Patel; K. Gopakumar
In this paper, two different schemes for three-level voltage space vector generation for induction motor drives are proposed. In a conventional 3-phase four-pole induction motor, there exist two identical winding coil groups per phase around the stator, which are connected in series and spatially apart by two pole pitches. In this work, these two identical voltage profile pole pair winding coils in each phase of the induction motor are disconnected and reconnected appropriately to achieve a drive scheme with reduced dc-link voltage. Two different schemes are proposed in the present work. In the first scheme the identical pole phase winding groups are connected in two star groups and fed from the independently controlled (decoupled control) two two-level inverters from both sides of the motor with the same dc-link voltage with half the magnitude compared to conventional NPC three-level inverter. The phase windings are connected in two star groups, so there will not be any path for zero sequence currents. Thereby requirement of isolated voltage sources is eliminated compared to the previous open-end winding multilevel inverter schemes. In the second scheme the identical pole phase winding groups are connected in parallel and fed from the two two-level inverters from both sides of the motor with one fourth the dc-link voltage (compared to the conventional NPC three-level inverter) resulting in a three-level voltage space vector across the motor phase windings. The schemes presented in this paper, does not require any special design modification for the induction machine. For the present study, a four pole IM drive is used, and the scheme can be easily extended to induction motors with more than four poles. The proposed scheme is experimentally verified on a four pole, 5HP induction motor drive.

Digitally Implemented Novel Technique to Approach Natural Sampling SPWM  [Details]
By Mohan Renge, Hiralal Suryawanshi, Madhuri Chaudhari
Digital signal processor (DSP) based sinusoidal pulse width modulation (SPWM) uses symmetrical and asymmetrical regular sampling. These samplings do not attain the performance of natural SPWM at low sampling. This paper presents a simple technique using digital sampling to approach naturally sampled SPWM. The proposed technique samples the modulating waveform at every peak of the triangular carrier signal and calculates precise magnitude of modulating signal for the instant of intersection. This signal has enough information to minimize the error in switching instant. The original modulating signal appears in the PWM output spectra unattenuated, without any distortion components, and without phase delay, regardless of the frequency or modulation depth of that signal. The presented technique is suitable for real time implementation using commercial DSP. This technique is also applicable to multilevel inverter and does not generate superfluous pulses like asymmetrical sampling in the output voltage of multilevel inverter. Simulation and experimental results are presented to demonstrate and confirm the validity of the proposed technique.

Dynamically Reconfigurable Control Structure for Induction Motor Drives on FPGA Control Platform  [Details]
By Shashidhar Mathapati; Joachim Böcker
The concept of dynamic reconfiguration of controls is commonly known in Fault Tolerant Control (FTC) systems. The general idea of this concept is highlighted and that can be extended to achieve the optimal performance from a plant in its whole operating region. Today, many industrial standard drives provide more than one control scheme for the drive control. The customer may chose between, e.g., flux-oriented control (FOC) and constant voltage frequency ratio control (v/f). However, the dynamic (on-the fly) change-over between these control schemes is usually not available as a feature, although it may be essential e.g. in cases of handling different operating modes optimally or as a fallback strategy in case of faults. The main emphasis of this contribution is to present the detailed concept, implementation and the experimental validation of dynamic reconfiguration between the well known control schemes for the induction machine. The idea is not only to show the switch-over between different control schemes, but also to utilize field-programmable gate arrays (FPGA) as basis for controller implementation. The inherent parallel execution of FPGA makes it easy to implement such dynamically reconfigurable control structure on a single control platform.

Miller Effect to Drive a Piezoelectric Actuator  [Details]
By Luis Sorcia-Navarro; Josep Rafecas-Sabaté; Miquel Teixidó-Casas; Joan Bergas-Jané; Daniel Montesinos-Miracle
This paper presents the intentional use of the Miller effect present in MOSFET devices to control a piezoelectric actuator. The Miller effect, normally neglected or minimized, can be useful to meet the dv/dt application requirements. A halfbridge converter is used as a power amplifier, where an external R-C network has been added to achieve the desired dv/dt. The transient semiconductor device behavior is simulated and tested experimentally.

Design of High Power Density Two-Stage AC/DC Notebook Adaptors Based on Loss Analysis  [Details]
By Jun-Young Lee
This paper presents design of two-stage scheme using BCM boost+LLC resonant converter for high power density AC/DC notebook adaptors. This scheme is generally used for several hundreds watt applications but has not been tried in small size power supplies such as adaptors. In order that this scheme becomes useful topology for adaptor applications, it should meet no load power consumption regulations as well as high efficiency. To do so, switching loss should be minimized and it can be accomplished by deriving device loss equations. Using the loss analysis, some design guidelines are suggested and verified with 85 W(18.5 V/4.6 A) design with 0.89 W/cm3. Test results shows that the measured efficiency is 90.6 % at 90 Vrms and no load power consumption can be reduced to about 0.5 W.

Field Oriented Control of IPM Drives for Flux Weakening Applications  [Details]
By Gianmario Pellegrino; Eric Armando; Paolo Guglielmi
Interior Permanent Magnet (IPM) drives are adapted to flux-weakening, then to constant power operation over a wide speed range. Most of the control strategies for IPM motor drives are based on the control of the current vector. Fluxweakening is obtained by proper current references, that are calculated according to the magnetic model of the motor. This approach needs the accurate characterization of the motor and it is sensitive to the inaccuracy and the variation of the model parameters. Moreover, in the case of a variable dc-link, an additional voltage loop is necessary to correct the current references values at different dc-link voltage levels. The direct control of the flux vector, in the stator flux oriented frame, is proposed here, with the aim of obtaining the constant voltage operation of the IPM motor drive in the flux weakening range by means of a very simple control algorithm. The proposed direct flux control is tested on an IPM motor drive designed for traction. The exploitation of the maximum torque in all the operating speed range is demonstrated. The control is also capable to adapt its flux and current set-points to different dc-link voltage levels with no need of additional voltage regulators. Discrete-time simulation and experimental results are presented and compared showing good accordance.

Diagnosis of Submersible Centrifugal Pumps: A Motor Current and Power Signature Approaches  [Details]
By Augusto Hernandez-Solis; Fredrik Carlsson
Early detection of undesired conditions during the operation of a centrifugal pump has become very important in order to avoid consequential damages, thus outage time and repair costs can be reduced. Faults in centrifugal pumps can be caused through the changes in flow conditions such as cavitation, that lead to impeller degradation and ultimately to the deterioration and breakdown of pump material. In this project the diagnosis of a submersible centrifugal pump is performed, proving that it is possible to detect not only when cavitation is present but also when it starts using the current and power signature analyses of its motor drive as diagnostic tools. Experimental currents and voltages are measured for different operating points of the pump in order to study the correlation between the cavitation phenomena and the power of the motor.


 EPE Journal Volume 20-1: Other 

EPE-PEMC 2010 in Ohrid (Republic of Macedonia)  [Details]
By B. Sneyers
Info about the EPE-PEMC 2010-conference, the 14th International Power Electronics and Motion Control Conference September 6-8, 2010

EPE 2011 - 1st Announcement and Call for papers  [Details]
By B. Sneyers
EPE 2011, Birmingham, UK: the 1st Announcement and Call for Papers