Showing papers in "IEEE Industrial Electronics Magazine in 2008"

The age of multilevel converters arrives

Abstract: This work is devoted to review and analyze the most relevant characteristics of multilevel converters, to motivate possible solutions, and to show that we are in a decisive instant in which energy companies have to bet on these converters as a good solution compared with classic two-level converters. This article presents a brief overview of the actual applications of multilevel converters and provides an introduction of the modeling techniques and the most common modulation strategies. It also addresses the operational and technological issues.

Control issues in adjustable speed drives

Abstract: Adjustable-speed electric motor/generator drives (ASDs) are used to save electric energy and increase productivity in variable-output work processes of all new and well-established industries such as: digital information gadgets, digital home appliances, automotive and robotics electric actuators, pump compressors, other vehicles, industrial processes, and distributed and renewable energy system electric generators. With power levels that go from less than 1 W to hundreds of megawatts, ASDs have become in the last 20 years a very dynamic worldwide industry/market. The recent advances in electric/magnetic materials, modeling tools, design and fabrication of electric machines for ASDs, corroborated with matched progress in ASD power electronics with power quality control, DSP menu based control, novel sensors and interfacing, field orientation and direct torque control (FOC and DTC), and advanced state observers for motion or current sensorless control, has prompted us to do this selective review. This article selects a few control issues in ASD, such as performance indices, three-phase ac motor control principles, wide constant power speed control, motion-sensorless control of ac drives, variable-speed ac generator control, and linear motor drives control, and discusses their basics, recent progress, and a few directions of ASD research and industrial development for the near future.

Hybrid wired/wireless networks for real-time communications

Abstract: In this article, some considerations are presented about the way several well-known industrial networks (based on both fieldbus and industrial Ethernet solutions) can be practically extended with wireless subnetworks that rely on popular technologies, such as IEEE 802.11 and 802.15.4. This results in hybrid networks, which are able to combine the advantages of both wired and wireless solutions. In particular, advantages and drawbacks of several interconnection techniques are highlighted and, depending on the wired networks specifically taken into account, some hybrid configurations that are able to cope in a satisfactory way with the tight timing requirements often imposed by industrial control systems are suggested.

Charging ahead

Abstract: With the constant performance improvement and cost reduction of power electronics and motor drives, more efficient vehicles such as electric, hybrid electric, and plug-in hybrid electric vehicles (PHEVs) are becoming a reality. The commonality between all advanced vehicles is the presence of electric propulsion powered by an electric storage system. As a result, the development of adequate energy storage systems is now more important than ever. High energy density, modularity, and affordability have made batteries the technology of choice for vehicular applications. In recent years, battery technology has made great strides in improving the energy and power density. Still, a tradeoff between power and energy must be made to best meet space and weight constraints. In this article, we shed some light on this tradeoff. We also look at how batteries can be represented with equivalent circuits. Finally, we go into some detail on battery management requirements that ensure that the batteries perform as expected. Power electronics has revolutionized motor drives, bringing within the realm of possibility electric drive-trains with extremely high performance. The motors themselves have been improved, offering higher reliability and better performance with a reduced cost. Unfortunately, the weak link in the electric drive-train development chain remains-energy storage. There are some advancements in energy storage device development that offer good promise in terms of energy density and power density but none have the desired combination of all of the following features: fast charging-discharging (high-power density), large-storage capacity (high-energy density), low cost, and long life.

Energy-efficient motors

Abstract: The use of a copper-squirrel cage in induction motors has been analyzed testing a prototype rated 1.1 kW and comparing the performances with a twin machine with an aluminum cage. The comparison has been made using torque, efficiency, starting torque, and starting current. For the considered machine size, the obtained results show that the simple substitution of the aluminum with copper can improve the efficiency of no more than 1.5% at rated load. Taking into account the copper market cost trend, the use of copper cage increases the break-even time due to the higher cost of copper rotor respect to the aluminum one. For this reason, the discussion about the use of copper cage can be still considered open.

Commercial impact of silicon carbide

Abstract: Evolutionary improvements in silicon (Si) power devices through better device designs, processing techniques, and material quality have led to great advancements in power systems However, many commercial power devices are now approaching the theoretical performance limits offered by the Si material in terms of the capability to block high voltage, provide low on-state voltage drop, and switch at a high frequency This article presents the opportunities and challenges in realizing the full potential of SiC power devices

Integrating power quality to automated meter reading

Abstract: This paper discusses the metering technologies and communications systems that enable the development of automated meter reading (AMR) systems. Power quality is one area where the AMR system can be very valuable. This article investigates the challenges in the integration of PQ monitoring system measurements in a distribution automation system (DAS).

When loads stray: Evaluation of Different Measurement Methods to Determine Stray Load Losses in Induction Machines

Abstract: The efficiency data provided by manufacturers are measured or calculated according to different national and international standards. These standards use different means to incorporate the stray load losses; thus the efficiency values obtained from different testing standards can differ by several percent. This leads to problems in competition and to a potentially confusing situation for the manufacturers and customers. This paper evaluates different measurement methods to determine stray load losses in induction machines.

Advances on Remote Laboratories and e-Learning Experiences (Gomes, L. and Garcia-Zubia, J., Eds.) [Book News]

Abstract: This book presents an overview of experiences related to remote laboratory usage for teaching and learning processes. The book covers many topics related to remote laboratories which have the potential to drastically change the economics of the lab experience in science and engineering education. There are five section: "Remote Labs: Past and Future"; "Remote Labs Impact Within the Learning Process"; "Remote Labs Development Issues"; "Remote Labs in Use"; and "New Challenges." This book is strongly recommended for its comprehensive view of the potential for e-learning and usage of remote laboratories backed by an international group of specialists in the field.

Getting around in electric vehicles

Abstract: The article has presented the electric tilting three-wheel vehicle (ET3WV) developed at the University of Padova, Italy, for urban mobility. It is characterized by an innovative connection between the tilting front module and the nontilting rear module, and by advanced solutions for the electric propulsion system. The design of the mechanical layout, of the traction drives, of the battery, and of the control circuitry of the vehicle were described, and its characteristics and driving performance were reported. Besides excellent performance in terms of acceleration and range, superior lateral stability and good maneuverability were achieved. Further work is mainly addressed to enhance the electric propulsion systems by providing the traction drives with torque control and flux-weakening features, with the latter being helpful for increasing the cruising speed out of the urban areas.

Handbook of Automotive Power Electronics and Motor Drives (Emadi, A.; 2006) [Book News]

Abstract: This handbook is a comprehensive reference of automotive electrical systems and includes 31 chapters, each contributed by specialists from different countries in Europe, Asia, and the United States. The book is organized into five parts: "Automotive Power Systems"; "Automotive Semiconductor Devices, Components, and Sensors"; "Automotive Power Electronic Converters"; "Automotive Motor Drives"; and "Other Automotive Applications." Despite the editor's excellent work, a certain overlapping and repetition can be found in the text, which is understandable due to multiple authorship. In addition, one chapter title is misleading, covering different material than what is suggested. Otherwise, the content is easy to read and presented in an interesting manner. Each chapter begins with an introduction and is supplemented with a list of references at the end. The book is recommended for a wide audience of engineering educators, students, and engineers in industry who are interested in automotive power electronics and drives.

Get real: Real Time Software Design for Safety-and Mission-Critical Systems with High Dependability

Abstract: Real-time control software has been applied to a wide variety of real-world systems for diverse military, aerospace, industrial, medical, and civil applications. Most real-time systems are distributed and embedded applications, which are made up of heterogeneous components including sensors, microprocessors, and actuators. These components intensively interact with each other and with their environments. Thus, there are many dynamic and uncertain factors in these systems. Distinguished from software design for traditional industrial automation systems, real-time software is usually safety- or mission-critical, which requires high dependability during system operations. Such a system not only needs to satisfy all the functional requirements but also fulfill various end-to-end quality-of-service (QoS) demands such as timeliness, availability, fault tolerance, and so on. In such real-time systems, the available system resources such as central processing unit (CPU) cycles, communication bandwidth, and storage memory are usually restricted, and thus efficient resource allocation in different operation scenarios for QoS assurance is highly desired. As a result, the design of such types of complex real-time software is quite challenging and it is significantly distinct from the conventional non-real-time software design.

Control programming using Java

Abstract: Networking and distributed applications have an increasing relevance in industrial automation as the horizontal and vertical integration of control systems progresses. In this context, object-oriented programming concepts and languages like Java become more and more interesting for all levels of automation. Within this article the state of the art in real-time Java and its applicability in the automation domain are discussed and an example for an implementation of a run-time environment utilizing the real-time specification for Java (RTSJ) will be introduced.

Virtualization-Enabled Industrial Grade Software Platforms [Industry Forum]

Abstract: Virtualization enables device designers to host multiple operating systems (OSs) concurrently on a single chipset in a device and liberates equipment manufacturers from the constricting offerings of a single OS. Virtualization for embedded devices enables secure and hybrid environments to be deployed simultaneously and readily.

A patented drop-free trocar for ophthalmic applications: design and realization [From Mind to Market]]

Abstract: Currently, there is no commercial device capable of stopping the outlet of the intraocular biological fluid during minimally invasive ophthalmic surgery. While solving this problem is not simple, in this article we describe the realization of a novel device capable of limiting the problem. In this research, a novel drop-free trocar that allows the cessation or reduction of the outflow of vitreous humour during a typical minimally invasive ophthalmic surgical procedure has been designed and realized.

Switching loss reduction through digital burst technique in TV power supply [From Mind to Market]

Abstract: Digital burst mode is an operation that can be used to control power transistor switching by the microprocessor signal. This also allows burst mode to be extended to future applications, such as multiple regulation in TV and other audio/video products. This technique substantially reduces stress for the main switching transistor during standby mode since it is not a complete turn-off.

Size matters: next generation wireless networks[industry forum]

Abstract: This article describes an alternative MESH approach that simplifies deployment and reduces costs significantly. Using the right technology tool and paying attention to practical business costs can meet the needs of the consumer while still making network deployment profitable for the operator. The scalability of the solution and the comparison example shown in the article indicates that size is important in the deployment of next generation wireless networks for simplifying deployment and reducing costs to network operators.

Automotive Fan Control with Smart Power Switch [From Mind to Market]

Abstract: This article presents a fan control unit requiring 30 A motor currents up to 20 kHz PWM. The smart integrated circuit (IC) used here includes a self-protected high-side switch with 4 mOmega RDSON, all digital control from a microcontroller, and extended diagnostics. High-current switching at high frequency generates electromagnetic interference (EMI) and power losses. Corner rounding and slew rates were optimized to reduce EMI filter size on the module. The power QFN (PQFN) package, half the size of the equivalent conventional package, helps to evacuate high power dissipation during switching. A smart power switch, combined with a 16-b microcontroller (MCU) and the control area network (CAN) communication protocol, provides an embedded solution, bringing cost savings on the system.

Measurements and power systems (reviews of "Principles of Electrical Measurement"; Tumanski, S.; 2006 and "First Course on Power Systems"; Mohan, N.; 2007) [Book News]

Abstract: Two books are reviewed in this issue: Principles of Electrical Measurement (Tumanski, S.; 2006) and First Course in Power Systems (Mohan, N.; 2007).

Reviews of "Electrical Drives and Magnetic Components" (Boldea, I. and Nasar, S.A.; 2006) and "Integration Technologies for Industrial Automated Systems" (Zurawski, R., Ed.; 2006) [Book News]

Abstract: The following two books are reviewed: Fundamentals of Electrical Drives by A. Veltman, D.W.J. Pulle, and R.W. De Doncker, published in 2007, and Inductors and Transformers for Power Electronics by Alex Van den Bossche and Vencislav Cekov Valchev, published in 2005.

Industrial control (review of "Advanced Control of Industrial Processes: Structures and Algorithms"; Tatjewski, P.; 2007) [Book News]

Abstract: The new handbook by Dr. Peng Zhang, from Beijing Normal University, China, covers the main problems related to industrial control and automation technology. The handbook consists of following chapters: Sensors and Actuators for Indus1) trial Control (180 pages), Computer Hardware for Industrial 2) Control (68 pages), System Interface for Industrial 3) Control (161 pages), Digital Controllers for Industrial 4) Control (135 pages), Application Software for Industrial 5) Control (98 pages), Data Communications in Distrib6) uted Control System (95 pages), System Routines in Industrial 7) Control (74 pages). In contrast to other related handbooks [1], [2], where the description of technical material is in the form of tutorials, technology, and overviews written by different industry and academic experts, Industrial Control Technology is presented by a single author. The text includes typically basic principles, specifications, and applications areas. Also, the most important standards (when applied, for example, SCADA protocols) are cited. An important and unique value of the book are the references presented separately in each chapter. Most of these references give direct address to the Web sites with industry technical manuals, introductory, or demonstrational materials. This is very convenient and I do not hesitate to recommend this new and attractive handbook to a wide audience of engineering educators, students, and engineers in industry who are interested in modern industrial control and automation technologies. —Marian P. Kazmierkowski

Industrial control (review of "Industrial Control Technology. A Handbook for Engineers and Researchers"; Zhang P.; 2008) [Book News]

Abstract: T he new handbook by Dr. Peng Zhang, from Beijing Normal University, China, covers the main problems related to industrial control and automation technology. The handbook consists of the following chapters: Sensors and Actuators for Indus1) trial Control Computer Hardware for Industrial 2) Control System Interface for Industrial 3) Control Digital Controllers for Industrial 4) Control Application Software for Industrial 5) Control Data Communications in Distrib6) uted Control System System Routines in Industrial 7) Control. In contrast to other related handbooks [1], [2], where the description of technical material is in the form of tutorials, technology, and overviews written by different industry and academic experts, Industrial Control Technology is presented by a single author. The text includes basic principles, specifications, and applications areas. Also, the most important standards (when applied, for example, SCADA protocols) are cited. An important and unique value of the book are the references presented in each chapter. Most of these references directly address Web sites with industry technical manuals or introductory or demonstrational materials. This is very convenient, and I do not hesitate to recommend this new and attractive handbook to a wide audience of engineering educators, students, and engineers in industry who are interested in modern industrial control and automation technologies.