Papers by Mark McGranaghan
Power quality (PQ) has become an important concern for utility, facility, and consulting engineer... more Power quality (PQ) has become an important concern for utility, facility, and consulting engineers in recent years. End-use equipment is more sensitive to disturbances that arise both on the supplying power system and within the customer facilities. Also, this equipment is more interconnected in networks and industrial processes so that the impacts of a problem with any piece of equipment are much more severe. The increased concern for PQ has resulted in significant advances in monitoring equipment that can be used to characterize disturbances and PQ variations. Analysis tools can present the PQ information as individual events (disturbance waveforms), trends, or statistical summaries. By comparing events with libraries of typical PQ variation characteristics and correlating with system events (e.g., capacitor switching), causes of the variations can be determined. In the same manner, the measured data should be correlated with impacts to help characterize the sensitivity of end use...
IEEE Power and Energy Magazine, 2017
Microgrids have long been deployed to provide power to customers in remote areas as well as criti... more Microgrids have long been deployed to provide power to customers in remote areas as well as critical industrial and military loads. today, they are also being proposed as grid-interactive solutions for energy-resilient communities. such microgrids will spend most of the time operating while synchronized with the surrounding utility grid but will also be capable of separating during contingency periods due to storms or temporary disturbances such as local grid faults. properly designed and grid-integrated microgrids can provide the flexibility, reliability, and resiliency needs of both the future grid and critical customers. these systems can be an integral part of future power system designs that optimize investments to achieve operational goals, improved reliability, and diversification of energy sources. the key components of a microgrid are the isolating device at the point of interconnection (poi); the electric and thermal ©istockphoto.com/faithiecannoise Transmission Operations
2007 IEEE Rural Electric Power Conference, 2007
Fault location is of considerable interest for utilities to improve their reliability and speed s... more Fault location is of considerable interest for utilities to improve their reliability and speed storm restorations. Power quality recorders, relays, and other monitors can provide information to help locate faults. In this paper, some basic impedance-based fault-location methods are evaluated on utility measurement data with known fault locations. The main finding is that reasonably accurate fault locations are possible on a wide range of distribution circuits with either feeder-level or bus-level substation monitoring. Another important finding described is how monitoring can be used to estimate the parameters of the fault arc. This can improve fault locations and help with accident investigations, equipment failure forensics, and other hazards related to the power and energy created by the arc.
IEEE PES General Meeting, 2010
The failure of several transmission capacitor banks prompted The United Illuminating Company to p... more The failure of several transmission capacitor banks prompted The United Illuminating Company to perform an engineering study to evaluate the transient recovery voltage capabilities of existing 123-kV, oil-filled capacitor bank circuit breakers at the East Shore 115-kV substation. The study determined if the transient recovery voltage capability of existing bus and capacitor bank circuit breakers is sufficient for the present system configuration. Furthermore, the study determined the required design and application changes related to the circuit breakers and capacitor bank component equipment, required to ensure that the bus and capacitor bank circuit breaker transient recovery voltage capabilities are not exceeded. The study recommended a future capacitor bank configuration to mitigate transient recovery voltage issues. The results of the study also lead to an expansion of the study area to include an adjacent substation, Grand Avenue Substation, due to concerns about the required transient recovery voltage capabilities of new gas-insulated switchgear to be installed. Index Terms-Transient Recovery Voltage (TRV), pre-insertion (closing) resistors, three phase grounded fault, three phase ungrounded fault, re-strike, inrush current, outrush current, reactor, circuit breaker, circuit switcher, rate of rise of recovery voltage (RRRV). .
IET Conference Publications, 2009
Power monitoring systems (power quality monitors, digital fault recorders, digital relays, advanc... more Power monitoring systems (power quality monitors, digital fault recorders, digital relays, advanced controllers, etc.) continue to get more powerful and provide a growing array of benefits to overall power system operation and performance evaluation. Permanent monitoring systems are used to track ongoing performance, to watch for conditions that could require attention, and to provide information for utility and customer personnel when there is a problem to investigate. An important development area for these monitoring systems is the implementation of intelligent systems that can automatically evaluate disturbances and conditions to make conclusions about the cause of a problem or even predict problems before they occur. This paper describes the development of a Next Generation Power Information System that will provide an open platform for implementing advanced monitoring system applications that involve integration with many different data sources. The work builds on many years of experience with software for management and analysis of large power quality monitoring systems.
IEEE Transactions on Power Systems, 1987
One of the functions proposed for distribution automation systems is automated capacitor switchin... more One of the functions proposed for distribution automation systems is automated capacitor switching to control power factor and voltage profile on feeder circuits. This is one of the functions being implemented as part of the Athens Automation and Control Experiment on the Athens Utilities Board (AUB) in Athens, Tennessee. A concern with automated capacitor switching is the increase in harmonic and transient voltages due to different capacitor configurations on the distribution system. A study was performed to evaluate the impact of the automated capacitor switching on the AUB distribution system. The study has identified problem areas, methods for determining the problem areas, and possible solutions. The substation capacitor banks were found to be the dominant factor in both the transient and harmonic repsonses of the distribution system. The harmonic response of the system is dominated by the parallel inductance/capacitance of the circuit comprised of the substation capacitor and equivalent source reactance at the substation. The transient analyses indicated that when the substation capacitor is energized, magnified transient voltages can occur at switched-in feeder capacitors. An evaluation of the effect of automated capacitor switching is necessary to properly design the automated capacitor switching schemes and the required arrester protection for any harmonic and/or transient overvoltage contingency.
IEEE Transactions on Power Delivery, 1986
... VariC:Luver, rmitted gebruary 1'.'18t5: mace aVa.i abLe fcr orirtirn Iy 4,, t 96 5-... more ... VariC:Luver, rmitted gebruary 1'.'18t5: mace aVa.i abLe fcr orirtirn Iy 4,, t 96 5-. Mark F. McGranaghan McGraw-Edison C6mpany Power Systems Division Canonsburg, PA 15317 This paper is an overview describing potential problems associated with large EHV capacitor ...
IEEE Transactions on Power Delivery, 2008
... Statistical Process Control Methods Nitika V. Mago, Surya Santoso, Senior Member, IEEE, and M... more ... Statistical Process Control Methods Nitika V. Mago, Surya Santoso, Senior Member, IEEE, and Mark F. McGranaghan, Senior Member, IEEE ... The control limits are selected such that the probability of a data point lying beyond the limits due to random causes is very small. ...
IEEE Transactions on Industry Applications, 2007
ABSTRACT Power quality standards provide the basis for achieving compatibility between the charac... more ABSTRACT Power quality standards provide the basis for achieving compatibility between the characteristics of the electric supply system and end use equipment. They provide the methods for evaluating performance, define equipment requirements, and outline relative responsibilities. This paper describes the status of important power quality standards around the world and presents a roadmap for ongoing standards development.
IEEE Transactions on Industry Applications, 2007
Reliability indices for distribution systems are used by utilities and regulators to benchmark pe... more Reliability indices for distribution systems are used by utilities and regulators to benchmark performance and prioritize investments in projects to improve performance. However, there can be many variations in the methods used to describe reliability levels, and the indices used may not be the best measures of system performance in terms of the impacts on customers. This paper describes the concept of a "service quality index" that can be used to characterize system performance in a manner that is more appropriate for customers, taking into account customer quality and reliability requirements and expectations
IEEE Transactions on Industry Applications, 1999
This paper discusses the application of the revised IEEE 519 harmonics standard to typical indust... more This paper discusses the application of the revised IEEE 519 harmonics standard to typical industrial facilities employing adjustable-speed drives (ASD's). The harmonic generation characteristics of ASD's are described. Requirements for control of the harmonic currents are developed as a function of the ASD characteristics, overall plant loading level, power system characteristics, and power-factor-correction requirements. Filter design procedures are presented for controlling the harmonic currents injected into the power system.
IEEE Power and Energy Magazine, 2010
ASSET MANAGEMENT IS MORE important than ever for electric utilities. Many power systems have asse... more ASSET MANAGEMENT IS MORE important than ever for electric utilities. Many power systems have assets that are aging, investment is limited, and at the same time we are introducing new technologies on the grid that must be maintained as part of overall asset management systems. Investment in new monitoring and communications infrastructure (often referred to as the smart grid) is opening new opportunities for improved asset management strategies. However, the smart grid is also introducing new challenges in the management, integration, and analysis of tremendous amounts of data that can be available. This issue explores the relationship between the smart grid and asset management—new technologies, systems, opportunities, challenges—and approaches being taken around the world to deal with the new asset management challenges.
IEEE Power and Energy Magazine, 2011
The most significant challenge in distribution management associated with the so called “smart gr... more The most significant challenge in distribution management associated with the so called “smart grid” is that the distribution system becomes an active system-with distributed generation, smart customer loads, electric vehicle charging, smart inverters, distributed storage, and so on. The challenge of an active distribution system affects both the planning functions and the real-time operations of the system. The transition to an active distribution system does not change the need to maintain and improve reliability.
EURASIP Journal on Advances in Signal Processing, 2007
Power quality monitoring has expanded from a means to investigate customer complaints to an integ... more Power quality monitoring has expanded from a means to investigate customer complaints to an integral part of power system performance assessments. Besides special purpose power quality monitors, power quality data are collected from many other monitoring devices on the system (intelligent relays, revenue meters, digital fault recorders, etc.). The result is a tremendous volume of measurement data that is being collected continuously and must be analyzed to determine if there are important conclusions that can be drawn from the data. It is a significant challenge due to the wide range of characteristics involved, ranging from very slow variations in the steady state voltage to microsecond transients and high frequency distortion. This paper describes some of the problems that can be evaluated with both offline and online analyses of power quality measurement data. These applications can dramatically increase the value of power quality monitoring systems and provide the basis for ongoing research into new analysis and characterization methods and signal processing techniques.
IET Conference Publications, 2009
Customer loads were linear in nature. When a sinusoidal voltage was supplied to them, they drew a... more Customer loads were linear in nature. When a sinusoidal voltage was supplied to them, they drew a sinusoidal current. They typically fell into the categories of lighting, heating, and motors. In general, they were not very sensitive to momentary variations in the supply voltage, such as transients and voltage sags. The loads were not connected together in networks so grounding issues other than safety were not very critical.
IEEE Power and Energy Magazine, 2016
The role and operation of the electric power system is evolving to accommodate changes in the way... more The role and operation of the electric power system is evolving to accommodate changes in the ways electricity is produced, delivered, and used. Consumers have increasing choice and control over their electricity service. The range of choice is diverse: owning or leasing generating systems [such as photovoltaic (PV), solar, thermal, wind, and biomass] and using storage options and technology to manage when and how they use electricity to manage costs. A power system that makes these distributed energy resources (DER) part of the performance optimization is referred to as an integrated grid (Figure 1).
The purpose of the paper is to present practical experience in the design and protection of trans... more The purpose of the paper is to present practical experience in the design and protection of transmission capacitor banks connected to typical gas-insulated substations. The paper describes common transient phenomena associated with gas-insulated switchgears, and the design and configuration of transmission capacitor banks for mitigating issues related to transient recovery voltage impacts on the circuit breaker protecting the capacitor bank. The design of protective relaying for the capacitor banks, including restrike and arcing monitoring, is also described.
2004 International Conference on Power System Technology, 2004. PowerCon 2004., 2004
ABSTRACT With just-in-time production schemes, today's automotive manufacturers stretch f... more ABSTRACT With just-in-time production schemes, today's automotive manufacturers stretch flexible-automation and supply-chain management to the limit. Unscheduled downtime at the main assembly plant or at the outsourced supplier's facility can lead to lower productivity and lost profits. When a plant recently experienced four-cycle voltage sag, over $700,000 was lost in the following 72 minutes due to the shutdown of the process and required rework. With a myriad of robotics, programmable controllers and drive systems working in a real-time process environment, automotive manufacturing systems can be vulnerable to power quality issues. This paper explores areas of vulnerability from the body shop through the paint shop and final assembly and identify effective measures to increase the robustness of automotive process systems through this new premium service concept U.S. utilities such as TVA (Tennessee Valley Authority) along with Duke energy have joined EPRTs power quality in automotive research project This project promotes the concepts of solving power quality problems at the most economical level through empowering the end user with knowledge to solve power quality issues.
2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262), 2001
ABSTRACT Understanding the performance of the power system is becoming increasingly important. Th... more ABSTRACT Understanding the performance of the power system is becoming increasingly important. This performance information must be available in a form that customers can use to evaluate the impacts on their processes and to evaluate the economics of power quality improvement alternatives. The performance information should also be shared throughout the utility so that problem areas can be identified and solutions implemented. Technologies to continuously monitor performance are available and the Internet provides a convenient method for sharing the information with all interested parties United Illuminating has implemented a monitoring system that tracks the performance at all distribution substations. The information is available at all times via the corporate intranet so that disturbances and long term power quality issues can be conveniently evaluated and so that information to be shared with customers can be provided easily by customer service personnel This paper describes the power quality monitoring system and the information sharing technology. Important benefits of the system that have been realized by United Illuminating are described, including power quality and reliability, prioritizing system improvements, and identifying problem conditions
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Papers by Mark McGranaghan