IEEE Industry Applications Magazine

David Prince probably coined the term inverter. It is unlikely that any living person can now establish with certainty that Prince (or anyone else) was the originator of this commonly used engineering term. However in 1925 Prince did publish an article in the GE Review (vol.28, no.10, p.676-81) cited “The Inverter”. His article contains nearly all important elements required by modern ... View full abstract»

This work discusses Robert Jameson Van de Graff, a physicist at Princeton University (NJ, USA) and the history of the Van de Graff generator. The operation and applications of the Van de Graff generator are discussed briefly. Finally, various evolutions of the Van de Graff generator are also discussed. View full abstract»

Countries with a considerable number of photovoltaic (PV) installations are facing the challenge of overloading their power grid during peak power production hours if the power infrastructure remains the same. To address this, regulations have been imposed on PV systems to ensure that more active and flexible power control is performed. As an advanced control strategy, absolute active power contro... View full abstract»

This article shows that adjustable speed generators for wind turbines are necessary when output power becomes higher than 1 MW. The doubly fed induction generator (DFIG) system presented in this article offers many advantages to reduce cost and has the potential to be built economically at power levels above 1.5 MW, e.g., for off-shore applications. A dynamic model of the DFIG was derived to devel... View full abstract»

Bob Metcalfe, inventor of the Ethernet and a well-known technology visionary, once said, Over the past 63 years, we met world needs for cheap and clean information by building the Internet. Over the next 63 years, we will meet world needs for cheap and clean energy by building the Enernet. The Internet has resulted from revolutionary advances in electronics, telecommunications and information tech... View full abstract»

Current-differential principles are well known and commonly used for the protection of medium and large transformers, large motors, medium-voltage (MV) generators, MV and high-voltage buses, and any type of important power equipment with measurable input and output currents. However, is it practical to protect low-voltage (LV) distribution buses using differential protection? This article describe... View full abstract»

Most of the failures in oil-lubricated journal bearings are associated with mechanical instabilities produced by lubrication-system problems or bearing wear and result in increased shaft vibration. Therefore, monitoring the journal-bearing condition in the field relies mainly on the analysis of proximity-probe or accelerometer signals. However, not all motors with journal bearings are equipped wit... View full abstract»

To help reduce losses in a distributed generation system, this article proposes a suitable method involving a three-phase multifunctional grid-connected solar energy conversion system (SECS). A two-stage circuit topology is used in this work; the first stage is a boost converter, which serves the purpose of maximum power point tracking (MPPT), and the second stage is a four-leg voltage source conv... View full abstract»

Cybersecurity is a topic of increasing importance and interest to small utility operators like rural electric associations. Cyberattacks are a threat to our society's functioning, and cybersecurity is an urgent need in areas that include national security, business operations, and regulatory compliance. Several fundamental concepts can guide an operator when implementing a cybersecurity plan. Oper... View full abstract»

Small power systems, such as those found on offshore platforms, are fragile, yet they must operate reliably for economy and the safety of both personnel and the environment. These systems often include combustion turbine generators for the main process power requirements and black start diesel generators that can supply essential and emergency buses; the diesel generators can also be used to resta... View full abstract»

Electric motors have unique vibration characteristics mainly due to the coupling between electric and mechanical forces and the construction of their rotors. Rotors are made up of stacked parts and a copper or aluminum cage material that is casted, welded, or brazed and shrunk to fit on a shaft, which may also have welded arms. This built-up construction of different materials with different therm... View full abstract»

Electric and hybrid vehicles continue to demand a considerable share of the automotive market. This movement has been enabled by the recent technological improvements in the areas of electric motors, power electronics, and energy storage. While many electric vehicles (EVs) are on the market, they are not as cost competitive as conventional vehicles, and affordable cost is necessary for large-scale... View full abstract»

An improved enhanced phase-locked loop (EPL)-based control algorithm for a double-stage solar photovoltaic (PV) grid-interfaced power generating system is presented in this article. It also mitigates power quality (PQ) problems in a three-phase, four-wire (3P4W) distribution system under variable solar intensity. The proposed solar PV grid-interfaced system consists of a solar PV array, a boost co... View full abstract»

The Stator-current signature analysis of induction motors is a proven method to diagnose rotor squirrel-cage winding defects and air-gap-eccentricity problems. With this technology, specific frequency-current components can be identified as an indication of cage-winding defects as well as a nonuniform gap between the stator and rotor. Since these data are generally collected periodically, it is im... View full abstract»

This article presents an overview of switching regulated DC-DC power convertor electromagnetic interference problems and possible solutions, with special emphasis on power line conducted emissions and power line input filters. Potential stability and performance problems that can be caused by the interaction between the power line input filter and the switching regulator are discussed in detail. C... View full abstract»

The Mitigation of arc-flash incident energy is important to increase safety. One method is to reduce the duration of the arc flash by using protective relays to sense an arc-flash fault. This method requires a supply-side switching device that will respond to the protective relaying fast enough to mitigate the incident energy. In many existing installations, medium-voltage (MV) controllable fuses ... View full abstract»

The trend toward electrical rather than mechanical drivers for offshore installation has led to the implementation of large electrical systems and power generation. Due to the offshore environment constraints, such as weight and footprint limitations, most of the installation remains operated at voltages of 13.8 kV and lower, which leads to specific constraints on the electrical network design. Th... View full abstract»

Three-phase induction motors are the “workhorses” of industry and are the most widely used electrical machines. In an industrialized nation, they can typically consume between 40 to 50% of all the generated capacity of that country. This article focuses on the industrial application of motor current signature analysis (MCSA) to diagnose faults in three-phase induction motor drives. MCS... View full abstract»

The period following World War II (WWII) saw a considerable increase in demand for electrical power throughout Brazil, particularly in the industrialized states. After WWII, the regions of Sao Paulo and Rio de Janeiro faced a serious shortage of electric energy. For many reasons, power companies did not meet this demand. The problems were pervasive: the depression years of the 1930s had seen a low... View full abstract»

IEEE 1584-2002 was developed to help protect people from arc-flash hazard dangers. The predicted arc current and incident energy are used in selecting appropriate overcurrent protective devices and personal protective equipment, as well as defining safe working distance. Since the magnitude of the arc current is inherently linked with the degree of arc hazard, the arc is examined as a circuit para... View full abstract»

The most common system studies done on power systems include: load flow, short-circuit, stability, motor starting, harmonic analysis, switching transient, reliability, cable-ampacity, ground mat and protection coordination studies. The three studies addressed in this article are short-circuit, coordination, and harmonic studies View full abstract»

The emphasis of this article is on distributed generators that are interconnected to with utility distribution systems. These will generally be units smaller than 10 MW. Larger units are generally connected directly to transmission facilities and will most likely be commercial power producers. The units installed on distribution systems will typically be no larger than 1 or 2 MW. These would be in... View full abstract»

Electricity is unique among energy sources in that its use is virtually ubiquitous in everyday life, yet it also has the potential to be instantly fatal when contacted. Due to its familiarity and commonplace use, people are often complacent about electrical hazards and underestimate the risks associated with exposure to electricity. Many veterans in the electrical industry came of age in an era wh... View full abstract»

Power electronics is a technology that deals with the conversion and control of electrical power with high-efficiency switching mode electronic devices for applications such as dc and ac power supplies, electrochemical processes, heating and lighting control, electronic welding, power line volt-ampere reactive (VAR) and harmonic compensators, high-voltage dc (HVdc) systems, flexible ac transmissio... View full abstract»

This article presents a detection method for an open-switch fault in cascaded H-bridge multilevel inverters (CHMIs). Recently, CHMIs were widely used in high-power systems. Therefore, the reliability of this topology has become an important factor. To improve the reliability, methods for detecting openswitch faults are required. The proposed method is based on the current path analysis according t... View full abstract»

High-speed electric motor variable speed drives used to drive centrifugal compressors of any size are proven technology, and the examples shown in this paper are exemplary for many other successful inscallations. Economics will not always justify their use, particularly if there is no reliable and economical source of electric power available at site, but most applications can ill-afford not to ev... View full abstract»

Electrical reliability can be measured by taking a systematic approach to documenting preventive maintenance (PM) records with a metric derived from its discovery finds. These finds, however minor, are leading indicators of equipment failures. Therefore, documenting and reviewing them can justify electrical PM programs, measure PM effectiveness, and optimize PM intervals. The investigation of a re... View full abstract»

This article serves as a primer for dc circuit breakers and presents a basic overview of dc power and dc applications in contrast with alternating current (ac) systems. This article also serves as a primer on the design of dc circuit breakers, with a focus on interruption. The lack of a zero crossing requires that the circuit breaker designs look beyond the commonly used approaches for ac interrup... View full abstract»

THE MARKET FOR INTEGRATED power systems for more electric aircrafts and, in particular, for unmanned air vehicles (UAVs) is rapidly developing [1]. Due to space constraints, a practical solution for UAVs is to employ electric-starter generators (ESGs) embedded in gas turbine engines to facilitate electric engine crank, assist the engine in reaching the desired idle speed, generate power to drive t... View full abstract»

Electric demand-side management (DSM) focuses on changing the electricity consumption patterns of end-use customers through improving energy efficiency and the optimal allocation of power. Demand response (DR) is a DSM solution that targets residential, commercial, and industrial customers, and is developed for demand reduction or demand shifting at a specific time for a specific duration. In the ... View full abstract»

This article discusses motors for compressors in domestic air conditioners, an area in which there is a strong demand for high efficiency and also reports the results of the efficiency improvement and productivity of a new core structure. An innovative core structure and manufacturing method boosts efficiency of permanent-magnet motors. This article presents the close relationship between the moto... View full abstract»

In this article, the term "electric bicycle" is used to describe "electric-motor-powered bicycles," including both fully and partially motor-powered bicycles. Here, the electric bicycle market would benefit from further research both on the battery and on the drive technology and their use with electric bicycles. In the United States, electric bicycles are currently used most commonly for short tr... View full abstract»

Electric demand-side management (DSM) focuses on changing the electricity consumption patterns of end-use customers through improving energy efficiency and optimizing the allocation of power. Demand response (DR ) is a DSM solution that targets residential, commercial, and industrial customers and is developed for demand reduction or demand shifting at a specific time for a specific duration. In t... View full abstract»

Current grid standards largely require that low-power (e.g., several kilowatts) single-phase photovoltaic (PV) systems operate at unity power factor (PF) with maximum power point tracking (MPPT), and disconnect from the grid under grid faults by means of islanding detection. However, in the case of wide-scale penetration of single-phase PV systems in the distributed grid, disconnection under grid ... View full abstract»

This article studies the control configuration of a microgrid-connected photovoltaic (MCPV) source. In the control of an MCPV, maximum power point (MPP) tracking, droop control, and dc bus voltage regulation are the main required functions. To increase their penetration in the microgrid, MCPV sources have to participate in the microgrid?s frequency regulation. Consequently, MCPVs may be forced to ... View full abstract»

This article has reported on an industrial R&D project aimed at identifying a cost-effective response to the more and more challenging high-speed motor requirements that presently come from the gas industry sector. To meet the very high efficiency, dynamic performance, and reliability standards required by cutting-edge turbomachinery drive applications, a special PM synchronous motor prototype has... View full abstract»

Protecting critical infrastructure such as electricity, oil, and gas to prevent catastrophic failure is imperative to maintain the functioning of today's technological world. The U.S. government is putting into place programs such as the North American Electric Reliability Corporation [12] and the Federal Energy Regulatory Commission [13] to ensure that monitoring solutions exist for these critica... View full abstract»

Adjustable speed AC drives with low input current THD are becoming increasingly important in industry. This article has detailed the implementation of a parallel active filter, which is integrated within a 450 kW adjustable speed drive to provide an overall system which conforms to IEEE 519, and which provides significant benefits on a system level. The design of the active filter is seen to be dr... View full abstract»

Building automation systems (BASs) are the key to improving the energy performance of buildings as well as the occupants' comfort. There is a need to build a knowledge base on the matter and to grow suitable algorithms for a smart management of intelligent buildings. Therefore, fuzzy logic is a valuable candidate for developing robust algorithms. The scope of this article is to validate a fuzzy-lo... View full abstract»

Light-emitting diode (LED) lighting offers important advantages for pulp and paper facilities, delivers improved performance and reliability, and significantly lowers the total cost of ownership compared to conventional lighting. This article examines the many benefits of LED lighting, including improved quality of light and color rendering, reduction in ultraviolet (UV) emissions that eliminates ... View full abstract»

This article presents the modeling and control of the integration of a StatCom (static-synchronous compensator) with SMES (superconducting magnetic energy storage system) and its dynamic response to system oscillations caused by a three-phase fault. It has been shown that the StatCom-SMES combination can be very effective in damping power system oscillations. Adding energy storage enhances the per... View full abstract»

Chock temperature control is an important issue in cold rolling mills. Traditional wired systems don't offer satisfactory results for practical use. Because of very low power consumption using Zigbee (IEEE 802.15.4) wireless technology, temperature sensors (up to 125 οC ) suitable for a tandem cold mill environment have been developed. The complete monitoring system includes repe... View full abstract»

Recently, the topic of grid integration of distributed energy resources (DERs) has been closely linked with developments in power electronics research. The experimental evaluation of control strategies for power interfaces usually requires a significant allocation of both time and resources, and this is why the power hardware-in-the-loop (PHIL) techniques have been introduced to help accelerate th... View full abstract»

It is estimated that about 80% of all photovoltaic (PV) modules are used in stand-alone applications. Continuous power is obtained from PV systems by using a storage buffer, typically in the form of a lead acid battery. Batteries used in PV applications have different performance characteristics compared with batteries used in more traditional applications. In PV applications, lead acid batteries ... View full abstract»

Both the renewable portfolio standard requirements and the potential to delay distribution upgrade expenditures has resulted in a vast increase of distributed energy resources (DERs) on utility systems. As a result, distribution engineers are confronted with the very challenging task of fulfilling the scope of a system impact study to determine whether there exists the potential for the DER to cre... View full abstract»

This article proposes a novel control technique for suppressing pulsating torques in permanent magnet synchronous motors (PMSMs) and synchronous reluctance motors (Syn-RMs). This torque-control system is based on instantaneous torque estimation with a rigorous analytical model that can account for spatial harmonics. Using this novel analytical model, the produced torque can be accurately estimated... View full abstract»

This article discusses green power distributed generation (DG) sources (of 10 MW or less), which are connected to a utility system at the distribution level, and their impact on distribution system reliability. The article also summarizes the specific reliability and protection issues in interconnecting green power generators to utility systems to mitigate the aforementioned reliability issues. Th... View full abstract»

Two squirrel-cage induction motors rated at 2,984 kW, 6.9 kV, 60 Hz, and 3,556 r/min with a direct start driving a main blower in a blast furnace facility present random trips during starts and also an event of motor burning. These trips interrupt the motor starting by 50 and 46 N function actuations. Considering the risk of motor damage, the consequent interruption of blown air supplied to the fu... View full abstract»

Arc-flash hazard assessment studies involving a very large oil and gas company's equipment rated 38 kV and below revealed locations with excessive arcflash incident energy. After conducting many additional studies of power distribution systems for various plants (e.g., refineries, gas plants, gas-oil separation plants, and natural gas liquid plants), we realized that dangerous locations (greater t... View full abstract»

When inverters in voltage control mode are paired with synchronous generators (SGs), they exhibit poor transient load sharing in islanded operation. It is well known that power electronics respond more quickly where the inverter initially picks up the majority of every load step, and the generator's output slowly increases until they reach their steady-state load sharing given by droop settings. T... View full abstract»