Showing papers in "IEEE Power & Energy Magazine in 2008"

Microgrids management

Abstract: The environmental and economical benefits of the microgrid and consequently its acceptability and degree of proliferation in the utility power industry, are primarily determined by the envisioned controller capabilities and the operational features. Depending on the type and depth of penetration of distributed energy resource (DER) units, load characteristics and power quality constraints, and market participation strategies, the required control and operational strategies of a microgrid can be significantly, and even conceptually, different than those of the conventional power systems.

Making microgrids work

Abstract: Distributed energy resources including distributed generation and distributed storage are sources of energy located near local loads and can provide a variety of benefits including improved reliability if they are properly operated in the electrical distribution system. Microgrids are systems that have at least one distributed energy resource and associated loads and can form intentional islands in the electrical distribution systems. This paper gives an overview of the microgrid operation. Microgrid testing experiences from different counties was also provided.

Getting Smart

Abstract: The smart grid entails a transformation to an information-enabled and a highly interconnected network between electricity consumers and electric suppliers embracing transmission, distribution, and generation.

The Wide World of Wide-area Measurement

Abstract: The interest in phasor measurement technology has reached a peak in recent years, as the need for the best estimate of the power system's state is recognized to be a crucial element in improving its performance and its resilience in the face of catastrophic failures. In most countries installing the phasor measurement units (PMUs) and getting to know the PMU system behavior through continuous observations of system events has been the first step. All installations are reaching for a hierarchical wide-area measurement system (WAMS ) so that the measurements obtained from various substations on the system can be collected at central locations from which various monitoring, protection, and control applications can be developed. In this article, experts from several countries summarize their WAMS -related activities in some detail. The contributions here provide an account of the most advanced stages in WAMS development in major world economies.

Design for distributed energy resources

Abstract: The blackout experiences have demonstrated the vulnerability of the interconnected electric power system to grid failure caused by natural disasters and unexpected phenomena. Changes in customer needs, additional stress due to liberalized electricity markets, and a high degree of dependency of today's society on sophisticated technological services also intensify the burden on traditional electric systems and demand for a more reliable and resilient power delivery infrastructure. This paper discusses the design of a restructured electric distribution network that employs a large number of small distributed energy resources (DER) units, which can improve the level of system reliability and provide service differentiations.

A larger role for microgrids

Abstract: In this paper the technical constraints imposed by the growing needs of distributed generation, DER, and demanding PQR requirements, the microgrid concept is evolving toward a potentially versatile solution. The growing body of technical publications includes analytical modeling that defines the theoretical basis; computer simulation studies that verify operation and performance: and laboratory-scale, community-scale, and utility-scale demonstrations and pilot projects that add field experience to theory and simulation. Similarly, vigorous efforts are underway to expand microgrid economic and regulatory analysis capability, but challenges remain. At the policy level, significant changes will be needed to facilitate capture of the benefits of microgrids.

Smart Integration

Abstract: Electric utilities in the United States and globally are heavily investing to upgrade their antiquated delivery, pricing, and service networks including investments in the following areas: -- smart grid, which generally includes improvements upward of the meters all the way to the transmission network and beyond -- smart metering, sometimes called advanced metering infrastructure (AMI), which usually includes control and monitoring of devices and appliances inside customer premises -- smart pricing including real-time pricing (RTP) or, more broadly, time-variable pricing, sometimes including differentiated pricing -- smart devices and in-home energy management systems such as programmable controllable thermostats (PCTs) capable of making intelligent decisions based on smart prices -- peak load curtailment, demand-side management (DSM), and demand response (DR) -- distributed generation, which allows customers to be net buyers or sellers of electricity at different times and with different tariffs, for example, plug-in hybrid electric vehicles (PHEVs), which can be charged under differentiated prices during off-peak hours. The main drivers of change include: -- insufficient central generation capacity planned to meet the growing demand coupled with the increasing costs of traditional supply-side options -- rising price of primary fuels including oil, natural gas, and coal -- increased concerns about global climate change associated with conventional means of power generation -- demand for higher power quality in the digital age.

Dawn of the grid synchronization

Abstract: In summary, the findings described in the article should serve as a base for deployment of individual roadmaps by the users and guide vendors to prioritize their development to support the grid revitalization and reliability for the 21st century.

Policymaking for microgrids

Abstract: Technically, microgrids are emerging as an outgrowth of dispersed on-site and embedded generation via the application of emerging technologies, especially power electronic interfaces and modern controls, and similarly, microgrid economic and regulatory analysis is generally rooted in the same approaches used to evaluate distributed energy resources (DER). As in the economics of many traditional on-site generation projects, the economics of heat recovery and its application by combined heat and power (CHP) systems is central to the evaluation of microgrids, and integration of this capability is a key requirement whenever CHP appears as an option. The recovery of waste heat offers a key advantage to generation close to loads but at the same time adds significantly to analysis complexity because of the need to simultaneously meet requirements for electricity and heat, plus the inevitability of storage, both active and passive, entering the equation. More novel is the economics of power quality and reliability (PQR), which in microgrids can potentially be tailored to the requirements of end uses in a manner only considered to a limited degree in utility-scale system; e.g., by interruptible tariff options. The economics of microgrids arises from evaluation methods for on-site generation from the customer perspective and from the traditional utility economics of expansion planning from the utility perspective. Both of these areas have received considerable attention, so a growing toolkit exists, but methods need reinforcement in some key regards. Central to public policymaking will be consideration of the societal impact of microgrids, especially since their adoption may change macrogrid requirements.

more power to you (review of Instantaneous Power Theory and Applications to Power Conditioning by Akagi, H. et al.; 2007) [book review]

Abstract: This review examines a book that deals with the instantaneous active and reactive power theory in a complete for, for the first time. As it presents such an in-depth look at the subject, the book may be destined to be a classic.

For the Good of the Grid

Abstract: The existing electricity infrastructure evolved to its technology composition today from the convolution of several major forces, only one of which was technologically based. Today opportunities and challenges persist in world-wide electric power networks, including reducing transmission congestion, increasing system/cyber security, and increasing overall system and end-use efficiency while maintaining reliability. And many other challenges engage those who plan for the future of the power grid: producing power in a sustainable manner (embracing renewable fuels while accounting for their scalability limitations; e.g., increased use of land and natural resources to produce higher renewable electricity will not be sustainable, and lowering emissions from existing generators), delivering electricity to those who don't have it (not just on the basis of fairness but also because electricity is the most efficient form of energy, especially for things like lighting), using electricity more wisely as a tool of economic development, and pondering the possible revival of advanced nuclear reactor construction.

Softening the Blow of Disturbances

Abstract: DC Interconnect (DCI) has been developing a concept that takes advantage of both ac and dc technologies to enable the electric power industry to meet future needs in a cost-effective manner. The solution, grid segmentation, involves decomposing existing large inter-regional networks (interconnections) into sets of asynchronously operated sectors interconnected exclusively by dc links.

Wind Power [a review of Grid Integration of Wind Energy Conversion Systems (S. Heier; 2006); book review]

Abstract: This book contains engineering information about the operating principles, design, and application of wind turbines. Grid integration is covered in much less depth and is largely focused upon issues within the medium-voltage collector systems of multi-unit wind farms. Topics covered include power-electronic converter systems, harmonics, filter design, and protection. The book is well suited as a text or reference book for engineering students or researchers. It would also be very useful to wind turbine designers, who need detailed equations and graphs to understand the intricate technical issues related to energy conversion or turbine components.

Phasing in the Technology

Abstract: This paper discusses the current state-of-the-art of phasor measurement devices and systems for wide-area monitoring, particularly in North America.

Gaining a Wider Perspective

Abstract: The recent world-wide rash of power systems blackouts has provided an added impetus to wide-scale deployment of phasor measurement units (PMUs). Initial applications of PMUs in the late 1980s and 1990s were isolated due to the limited infrastructure availability and lack of computational support for extensive processing of the networked information. Today, networks of hundreds of PMUs are in place and more are planned.The recognition that networks of PMUs can provide greater power system reliability is based on their ability to give direct access to the state of the power system at any given instant.

First steps to wide area control

Abstract: The implementation of synchronized phasor measurements for system monitoring and control is receiving unparalleled attention in the power industry.In this article, we describe recent work to incorporate phasor measurements from several locations in the transmission system into a control center state estimator, the prime application for assisting the operators to understand the operating state of the power system and for making informed decisions with respect to scheduling transmission capacity and responding to contingencies.

System-wide Protection

Abstract: By its very definition, as applied to power system protection, wide-area measurement systems (WAMSs) are a synergistic combination of relays, measuring instruments, control equipment, automation equipment, monitoring equipment, and communication employed to encompass extensive system elements as opposed to the more traditional view of individual equipment or point-to-point protection. The increasing world-wide application of digital devices and high-speed wideband communication and global positioning systems (GPSs) plus the growing acceptance of adaptive relay protection philosophy and practice have dramatically altered the fundamental role of power-system protection.

Destination: Perfection

Abstract: The objectives of the perfect power project include: (1) the achievement of system-wide perfect power and demonstration of its technological viability; (2) 50% peak demand reduction capability via on-site generation when called upon by ComEd/ PJM; (3) deferral of ComEd planned substation upgrades due to the demand reduction achieved; (4) demonstration of the economic value of perfect power, specifically the avoidance of outage costs and the introduction of significant savings and revenue from providing ancillary services; and (5) a design that can be replicated to any municipality-sized system where customers can participate in electric power market opportunities. Transforming the IIT power delivery infrastructure to achieve perfect power is a bold idea that will require a never-ending series of innovations. We have embraced the vision of the GEI and we look forward to sharing our progress with the power and energy community in the years to come.

Drive friendly

Abstract: Fuel cells are good energy sources to provide reliable power at steady state and supercapacitor energy storage devices can advance the load following characteristics of a fuel cell by providing a stronger power response to changes in system loading. During motor starts/stops or other considerable steps in load, the super-capacitors provide the balance of energy needed during the temporary load transition periods and also absorb excess energy from the generator source (motor braking). Adding supercapacitor energy storage to distributed power systems improves power quality and efficiency and reduces capital expenses by allowing the systems to be sized more closely to the steady-state power requirements rather than over-sizing the main generator to meet transient loading requirements.

Leader or follower [The Business Scene]

Abstract: As momentum towards smart grid grows, utilities need to get organized and systematically develop fact-based perspectives. The gap between leader and follower in the industry will widen as new implementations lead to more utilities establishing precedence and standards for how smart grid deployments should be defined.

smart grid millionaire

Abstract: Technology is now changing quickly enough in the energy industry that the field experience with network integration of photovoltaic (PV), with integration of wind power, with the increased energy storage as available with energy storage, and the resulting impact on reregulation and market interaction is hard to disseminate internationally. The integration of renewable resources and energy storage are widely documented as a viable solution.

A delicate balance in South America

Abstract: This article deals with the challenges of balancing the need for hydroelectricity with the impact on the environment. Economic efficiency, energy security, and environmental sustainability are concerns that must be considered in any energy policy in any given country. These key aspects remain challenged currently in South America. High energy consumption growth worldwide rising fossil fuels prices, strong environmentalist pressure toward reducing greenhouse gas effects, and promotion of renewable energy production have been a common challenge in South American energy markets. The development of vast unexploited hydroelectric resources is also at the center of attention, where its renewable character is being confronted with its environmental impact.

Eyewitness to dc history

Abstract: This issue's history article offers eyewitness accounts of two important events, 125 years apart, in the history of electric utility service. Thomas Edison's famous Pearl Street direct current (dc) generating station and underground distribution system in New York City went into service on 4 September 1882 and ended its service on 14 November 2007.

Single-Phase Tripping

Abstract: Reclosers in general, and specifically reclosers with single-phase tripping capability, have the ability to improve distribution system reliability significantly not just on the distribution feeder but also in wind generation, cogeneration, various motor loads, oil wells, agricultural entities, small industrial sites, and at substations that feed moderate rural, residential, and commercial loads. The intelligence built into today's microprocessor- controlled reclosers allows the devices to dynamically operate on a single-phase or three-phase basis depending on the applications and conditions (see Figure 11). Loop systems can further enhance the reliability of a power system through sectionalizing or removal of faulted line sections.

emission reduction

Abstract: Discusses how the electric power industry is building an environmentally sound future.

Payment versus bid cost [The Business Scene]

Abstract: This article summarizes the recent developments in the solution methodology of payment-cost minimization and the economic analysis of the two auction methods. Topics such as revenue adequacy implications are brought into discussion. Generally speaking, the research on the appraisal of the two auction methods is still at the early stages, and that a comprehensive study of the two auction methods is highly valuable for both researchers and industrial practitioners. This article can initiate more serious debate among researchers and stakeholders as to which objective should be used in ISO markets.

Striving for Power Perfection

Abstract: Entrepreneurial prototypes of the Galvin perfect power microgrid system architecture are being initiated in a variety of commercial settings that focus both on implementing specific perfect power business opportunities and on pursuing the various technical innovation breakthroughs identified in the course of the Galvin electricity initiative. A variety of specific commercial prototype demonstration sites are now being evaluated and site-specific designs, together with the appropriate implementation policy recommendations, will complete the commercial technology transfer of the initiative's results.

25-Hz at Niagara Falls [history]

Abstract: This article discusses a significant aspect of the production of 25-Hz AC power for use in large areas of western New York State. It also describes hydroelectric developments at Niagara Falls in the late 19th and early 20th centuries and details the establishment and growth of 25-Hz power on the United States side of the Niagara Frontier. One additional reason for the selection of 25-Hz generation at Niagara was the intended use of this power for conversion to DC.