Below is a list of technical papers that I have either authored or co-authored. These papers have been published in a variety of technical journals, conference proceedings, and magazines.

Title: Distribution System Power Quality Assessment Phase II: Voltage Sag and Interruption Analysis Authors: Christopher Melhorn (SM), Arindam Maitra (M), Wes Sunderman (M), Marek Waclawiak (M), and Ashok Sundaram (M) Date: September, 2005 Conference: IEEE PCIC 2005 Abstract: The quality of electricity service required by customers of all classes is increasing. This requirement for increasing quality is due to many factors, including increasing sensitivity of the devices used by customers and their awareness of the impacts of small variations in the quality of the electricity supply. In the early 1990s, EPRI initiated a project called the Distribution Power Quality (DPQ) Project, which resulted in power quality monitoring at 277 distribution sites statistically chosen throughout the United States to gain valuable knowledge regarding the frequency and severity of power quality events. This paper presents the findings of a follow-on project, referred to as DPQ II, which was conducted in 2001 and 2002. This project resulted in characterizing power quality in terms of short-duration variations such as voltage sags, voltage swells, and voltage interruptions. The characterization was based on analysis of data from 480 power quality monitors at different locations in a power system spanning a date range from August 30, 1993 through December 12, 2002. The results of the analysis that are presented in this paper provide a unique opportunity to understand the electrical environment in terms of short-duration variations and further validate the findings of DPQ I.

Title: Interpreting and Analyzing Power Quality Measurements Authors: Christopher J. Melhorn and Mark F. McGranaghan Date: November, 2004 Conference: EC&M November 2004, Volume 103, Number 11 Abstract: Power quality has become a key concern for utility, facility, and consulting engineers because end-use equipment is now more sensitive to disturbances arising from both the utility power supply and within a customer’s power distribution system. Also, this equipment is more interconnected in networks and industrial processes so that the impact of a problem with any one piece of equipment are much more severe. This increased awareness of the importance of power quality has generated significant advances in monitoring equipment that can characterize disturbances and power quality variations. Today’s monitoring tools can present information as individual events (such as in disturbance waveforms), trends, or statistical summaries. By comparing events with libraries of typical power quality variation characteristics, and correlating them with system events (such as capacitor switching), you can determine the causes of these variations.

Title: Automatic Evaluation of Capacitor Bank Concerns Using a PQ Monitoring System Authors: Santoso, Surya, Christopher J. Melhorn Date: May, 2004 Conference: PQA 2004 Abstract: Capacitor banks have long been widely used to provide voltage support and correct displacement power factor on power distribution systems. There are a significant number of capacitor banks on the system and problems with capacitor banks are one of the most important maintenance requirements on the distribution system. Switching problems can cause PQ problems for customers and faults on the system. This paper describes the specifications for an automatic system to identify capacitor bank operational problems based on analysis of data commonly available in power quality monitoring systems. The specifications address the following capacitor bank issues: Recognizing capacitor switching transients Determining the capacitor bank location relative to the monitoring system Capacitor switching transient magnification Problems with capacitor switching device (pole span, preiginitions, restrikes, etc.) Blown fuses and capacitor can failures Harmonic resonance caused by capacitor banks A host utility is being identified to test these functions in an actual monitoring system. Plans for the actual demonstration will also be presented.

Title: Automated Detection of Voltage Unbalance Conditions Authors: Sunderman, Wes, Christopher J. Melhorn, Fred Elmendorf, Dan Sabin Date: May, 2004 Conference: PQA 2004 Abstract: Capacitor switching operations are one of the most common causes of transient disturbances on the power system. They cause problems on both sides of the meter. Oftentimes, these problems are results of poor capacitor bank maintenance. Problems like blown fuses in the capacitor bank are only identified during infrequent inspections or when actual system problems (like unbalanced voltages) occur. Unfortunately, most utilities have little or no method for identifying these problems and correlating customer problems with the capacitor switching operations. This paper proposes an automatic evaluation system to continuously evaluate capacitor bank operations and their impacts on the power systems. It will be engineered to automatically identify capacitor switching events, pin-point the exact troublesome capacitor bank, detect and evaluate harmonic resonance problems associated with the capacitor bank, evaluate capacitor switcher performance, evaluate capacitor bank health (blown fuses, voltage unbalanced, etc), transient magnification and restrike conditions. This automatic system needs no additional equipment since it makes use of existing data and equipment. Therefore it is a valued-added application. It can be implemented as a standalone system, add-on to existing PQ analysis software (such as PQView), or embedded into power quality monitoring instruments.

Title: Distribution System Power Quality Assessment Phase II: Voltage Sags and Interruption Analysis Authors: Melhorn, Christopher J., et al Date: May, 2004 Conference: PQA 2004 Abstract: The quality of electricity service required by customers of all classes is increasing. This requirement for increasing quality is due to many factors, including increasing sensitivity of the devices used by customers and their awareness of the impacts of small variations in the quality of the electricity supply. In the early 1990s, EPRI initiated a project called the Distribution Power Quality (DPQ) Project, which resulted in power quality monitoring at 277 distribution sites statistically chosen throughout the United States to gain valuable knowledge regarding the frequency and severity of power quality events. This paper presents the finding of a follow-on project, referred to as DPQ II, which was conducted in 2001 and 2002. This project resulted in characterizing power quality in terms of short-duration variations such as voltage sags, voltage swells, and voltage interruptions. The characterization was based on analysis of data from 480 power quality monitors at different locations in a power system spanning a date range from August 30, 1993 through December 12, 2002. The results of the analysis that are presented in this paper provide a unique opportunity to understand the electrical environment in terms of short-duration variations and further validate the findings of DPQ I.

Title: Distribution System Power Quality Assessment Phase II: Voltage Sag and Interruption Analysis Authors: Christopher J. Melhorn, Ashok Sundaram Date: May, 2004 Conference: PQA 2004 Abstract: The quality of electricity service required by customers of all classes is increasing. This requirement for increasing quality is due to many factors, including increasing sensitivity of the devices used by customers and their awareness of the impacts of small variations in the quality of the electricity supply. In the early 1990s, EPRI initiated a project called the Distribution Power Quality (DPQ) Project, which resulted in power quality monitoring at 277 distribution sites statistically chosen throughout the United States to gain valuable knowledge regarding the frequency and severity of power quality events. This paper presents the finding of a follow-on project, referred to as DPQ II, which was conducted in 2001 and 2002. This project resulted in characterizing power quality in terms of short-duration variations such as voltage sags, voltage swells, and voltage interruptions. The characterization was based on analysis of data from 480 power quality monitors at different locations in a power system spanning a date range from August 30, 1993 through December 12, 2002. The results of the analysis that are presented in this paper provide a unique opportunity to understand the electrical environment in terms of short-duration variations and further validate the findings of DPQ I.

Title: Remote Monitoring and Control of Distributed Resources Authors: Melhorn, Christopher J., Mark Stephens Date: June, 2001 Conference: PQA 2001 Abstract: As distributed resources DR becomes more prevalent, the need to obtain information on the status of the distributed resources and power quantities will be essential. The ability to remotely communicate with distributed resources will greatly enhance the ability to obtain the necessary information needed in order to aggregate DR units throughout the power system. Information on power flow, both quantity and direction, DR status, and system demand are required in order for system operators to make decisions concerning the integration of DR units into the power system. By tying the control of the DR unit in with the monitoring of the power system, power brokers can easily respond to the need of end users by aggregating DR units from across the power system. This paper describes EPRI PEAC’s ongoing development of a remote monitoring, data acquisition and control system used to obtain this valuable information from our own Distributed Resource park (Distributed Generation and Energy Storage). The monitoring system offers the flexibility to view power quality, power flow, DR unit status, and other relevant data (temperature, gas flow, efficiency, etc.) information locally and via the World Wide Web (WWW). The method used to setup and interrogate monitoring instruments at remote locations is explored as well. Details on the remote system are presented.

Title: Application of Power Quality Monitoring Data for Predictive Maintenance Authors: Bell, Sandra C., Mike Ingram, Daniel Rubia, Ramon Saenz, Harry Simpson, Christopher J. Melhorn, John Harding Date: June, 2001 Conference: PQA 2001 Abstract: The term power quality refers to a wide variety of electromagnetic phenomena that characterize the voltage and current at a given time and at a given location on the power system. The increasing application of electronic equipment that can cause electromagnetic disturbances, or that can be sensitive to these phenomena has heightened the interest in power quality in recent years. This has led to the deployment of power quality monitoring systems at utilities and customer facilities to continuously record power quality parameters in the power system and to capture events based on user defined thresholds of voltage or current anomalies. The application of power quality monitoring data has so far been limited to the diagnosis of power quality problems at customer facilities and within the transmission/distribution system. The installed base of power quality monitoring systems has increased significantly over the past ten years. Systems that were initially installed for power quality reasons have shown that they also can provide information that can be used to improve system reliability. It is apparent that power quality is tied closely to the reliability of the power distribution system, including the health and reliability of the power delivery system apparatus. The ability to predict the failure of the components that comprise power delivery systems by using power quality monitoring systems makes them a useful tool in a Predictive Maintenance Program. The objective of this paper is to describe the methodology for utilizing power quality systems as an integral part of a predictive maintenance approach. The paper addresses requirements of implementing a PQ Monitoring based Predictive Maintenance (PQPM) system using an open architecture, defines the knowledge base that needs to be developed in order to process the power quality data for maintenance purpose, provides case studies to show how power quality monitoring data can be used as an indicator for detecting system anomalies and discusses the results of a research project with TVA to correlate power quality monitoring data with power system equipment failure database.

Title: Utilization of Web-based Power Quality Monitoring to Access Customer Power System Performance Authors: Melhorn, Christopher J., Sandy Smith, Peter Muccio, Frank Sinicola Date: February, 1999 Conference: DistribuTech 1999 Abstract:

Title: Power Quality: Opportunity or Obstacle? Authors: Hofmann, Peter, Frank Sinicola, & Christopher J. Melhorn Date: June, 1998 Conference: 1998 EPRI PQA Conference Abstract: With the dawn of deregulation upon us, utilities are recognizing the fact that deregulation is now a reality and in an effort to keep customers, many utilities are implementing power quality programs as an added value service to their customers. Using power quality as an opportunity to provide customers better service is an approach adopted by many utilities. Consolidated Edison Company of New York, Inc. (Con Edison) is one such utility. Con Edison has implemented several programs that have resulted in better response and service to customers. These services and programs are provided through the Con Edison Power Quality Service Center (CEPQSC), developed in conjunction with EPRI. This paper describes the programs that have been implemented by the CEPQSC and gives examples of the successes of these programs. Customer reaction to these programs is cited and the methodology for solving customer problems is discussed. These programs have additionally assisted in enhancing the internal operations for delivery of electric power.

Title: Evaluating Written-Pole Motor Generator Technology for Providing Voltage Sag Ride Through Authors: Melhorn, Christopher J., Peter Hofmann, Frank Sinicola, Ben Banerjee Date: June, 1998 Conference: 1998 EPRI PQA Conference Abstract: Today's high-tech computer and multi-media equipment require "clean" electric power protected against normal split-second voltage variations. Consolidated Edison's Power Quality group in cooperation with its Research and Development department researched, selected and installed state-of-the-art written pole motor-generators to provide this “clean” power in two locations. It is the first installation of its type in New York City. As part of this project, Con Edison has secured research funding from the Electric Power Research Institute (EPRI) to demonstrate the written pole technology at a site in a New York City office building and a facility located in Westchester County, New York. This research project includes monitoring and analyzing the power quality at the location, and evaluating the performance of the written-pole motor generators. The written-pole motor generator, also known as the Roesel Motor Generator (RMG®) is a continuous-duty device, which provides essential electrical loads with a continuous source of clean, regulated, and isolated 60-cycle power. When a loss or variation of input utility power occurs, the Roesel Motor-Generator is designed to supply constant frequency 60 cycle power within a specified voltage range for a minimum of 15 seconds with full rated load on the unit. At reduced loads it will supply power for up to 45 seconds. This paper describes the installed system, problems encountered during the installation and operation of the RMGs, and analysis of the effectiveness of the generators. Measurement data is included for both pre- and post-RMG installation.

Title: Accessing Power Quality Information and Monitoring Results Using the World Wide Web or a Private Corporate Web Authors: Melhorn, Chris, Pete Hofmann, Kelley Flatford, Sid Bhatt Date: March, 1997 Conference: EPRI PQA 1997 Abstract: Utilities all over the world are implementing power quality programs. These programs include system-wide monitoring projects as well as the evaluation of individual end-use power quality concerns and equipment. These evaluations and studies have resulted in a wealth of knowledge and data for utility power quality engineers collected by both EPRI and the individual utilities. The challenge has been to quickly and easily distribute this information to other utility employees, especially those employees who have to solve customer problems. Sending hard copies is inefficient and not cost effective. In addition, keeping track of this data and information becomes a major burden as the number of case studies performed grows. The PQ Database addresses this problem by providing a searchable repository for storing power quality related documents. It provides a media that is flexible enough to support this diverse data set. This program was developed and released by EPRI on CD-ROM and runs under the Microsoft Windows operating systems. However, this software package is a workstation version. The software is designed to be installed and run on each employee’s computer. With the explosion of the Internet and graphical web browsers, obtaining information is easier than ever before. Power quality information is no exception to this. Many utilities are implementing what is called an Intranet. This term is used to describe a company-wide “internal Internet” which is secure from the outside (firewall protected) but which gives employees access to information from various departments through the use of a standard web browser. Another feature developed for the Internet is monitoring power quality. Power quality monitoring information is now obtainable over the Internet. Rather than installing custom software on every engineer’s computer, a utility now has the option of using the Intranet and Internet to supply critical power quality measurements to all engineers and selected customers. The system is fully protected by the use of passwords, and since the user can only view the data, there is no chance of monitor thresholds being reset or data being erased. This paper describes both systems in detail and gives examples of utilities and large industrial and commercial companies currently using the system. A case study is presented on one utility’s approach to using the Intranet and Internet for accessing power quality information.

Title: An Evaluation of Energy Storage Techniques for Improving Ride-Through Capability for Sensitive Customers on Underground Networks Authors: Melhorn, Christopher J., Aubrey Braz, Peter Hofmann, Ralph Mauro Date: July, 1997 Conference: IEEE Transactions on Industry Applications, Volume 33, Number 4 Abstract: Most Con Edison customers are supplied through extensive network systems. These customers do not experience interruptions or outages except under very rare circumstances. This is a significant advantage for these customers since they do not normally need to apply energy storage systems for protection of critical loads. However, voltage sags, which occur whenever there is a fault on the power system, can affect the important loads. The sensitivity of some critical loads can cause dropout or mis-operation during voltage sag conditions. Some type of protection may be needed for these loads to provide ride through support during voltage sags. This paper describes the methodology used in a research project sponsored by EPRI and Con Edison to evaluate the need for voltage sag ride through improvement for the selected customers. Technologies that can supply the required ride through were evaluated and application considerations were developed. Two case studies are presented in this paper to illustrate the methodolgy used to perform the evaluations.

Title: Transient Effects of PWM Drives on Induction Motors Authors: Melhorn, Christopher J., Le Tang Date: July, 1997 Conference: IEEE Transactions on Industry Applications, Volume 33, Number 4 Abstract: With the advances in semi-conductor devices, adjustable speed drives (ASDs) have become more prevalent than ever before in industrial and commercial processes. Many facilities are installing ASDs to improve the efficiency of their processes and to increase the control of their processes. While the effects of ASDs on the power system are well known, many engineers and systems integrators are not aware of the effects that ASDs can have on the motor that is driven by the drive. This paper describes the techniques used to measure, analyze, and simulate the problems associated with the use of PWM ASDs to drive induction motors. Measures to mitigate these problems are also discussed. The Electro-Magnetic Transients Program (EMTP) is used to simulate the phenomena, compare results against measurements, and evaluate mitigation techniques.

Title: Flickering Lights — A Case of Faulty Wiring Authors: Melhorn, Chris Date: August, 1997 Conference: PQToday, Volume 3, Number 1, Page 4 Abstract:

Title: Interpretation and Analysis of Power Quality Measurements Authors: Melhorn, Christopher J., Mark F. McGranaghan Date: November, 1996 Conference: IEEE Transactions in Industry Applications, Volume 31, Number 6 Abstract: This paper describes advances in power quality monitoring equipment and software tools for analyzing power quality measurement results. Power quality monitoring has advanced from strictly problem solving to ongoing monitoring of system performance. The increased amount of data being collected requires more advanced analysis tools. Types of power quality variations are described and the methods of characterizing each type with measurements are presented. Finally, methods for summarizing the information and presenting it in useful report formats are described.

Title: An Evaluation of Energy Storage Techniques for Improving Ride-Through Capability for Sensitive Customers on Underground Networks Authors: Melhorn, Chris, Aubrey Braz, Peter Hofmann, Ralph Mauro Date: May, 1996 Conference: 1996 IEEE IAS I&CPS Technical Conference Abstract: Most Con Edison customers are supplied through extensive network systems. These customers do not experience interruptions or outages except under very rare circumstances. This is a significant advantage for these customers since they do not normally need to apply energy storage systems for protection of critical loads. However, voltage sags, which occur whenever there is a fault on the power system, can affect the important loads. The sensitivity of some critical loads can cause dropout or mis-operation during voltage sag conditions. Some type of protection may be needed for these loads to provide ride through support during voltage sags. This paper describes the methodology used in a research project sponsored by EPRI and Con Edison to evaluate the need for voltage sag ride through improvement for the selected customers. Technologies that can supply the required ride through were evaluated and application considerations were developed. Two case studies are presented in this paper to illustrate the methodolgy used to perform the evaluations.

Title: Voltage Sags: Their Impact on the Utility and Industrial Customers Authors: Davis, Tim, George Beam, Christopher J. Melhorn Date: May, 1996 Conference: 1996 IEEE IAS I&CPS Technical Conference Abstract: This paper describes the impact of voltage sags on the utility and industrial customers. Several utility measures are presented to minimize the customer's exposure to voltage sags. However, these measures cannot completely eliminate the impact of voltage sags on sensitive equipment. A case study is presented in this paper that includes measurement results that were used to characterize the voltage sags experienced on the utility system and in the industrial facility, simulation results that were used to develop “area of vulnerability curves” for the industrial facility, mitigation equipment that was employed to improve the sensitive equipment’s ride through capability, and the lessons learned from the systems approach analysis.

Title: Coping With Non-Linear Computer Loads in Commercial Building - Part II Authors: Melhorn, Christopher J. Date: January, 1996 Conference: emf-emi control Volume 2, Number 6 Abstract: N/A

Title: Coping With Non-Linear Computer Loads in Commercial Buildings - Part I Authors: Melhorn, Christopher J. Date: September, 1995 Conference: emf-emi control Volume 2, Number 5 Abstract: N/A

Title: Interpretation and Analysis of Power Quality Measurements Authors: Melhorn, Christopher J., Mark McGranaghan Date: September, 1995 Conference: 1995 PCIM/PQ Conference Abstract:

Title: Distribution Power Quality Measurement Program Authors: Sabin, D.D., T.E. Grebe, C.J. Melhorn, A. Sundaram Date: October, 1995 Conference: 48th Power Distribution Conference Abstract:

Title: Effect of High Efficiency Lighting on Power Quality in Public Buildings Authors: Melhorn, Christopher J., R.J. Schwabe, M. Samotyj Date: October, 1995 Conference: 1995 IEEE IAS Annual Technical Conference Abstract: The New York Power Authority (NYPA) is currently implementing a High Efficiency Lighting Program (HELP) in schools and public buildings within the State of New York. HELP focuses on the replacement of magnetic ballast fluorescent light fixtures with the new high efficiency electronic ballast fixtures. The use of electronic ballast can have an adverse effect on power quality. To determine the effects that the electronic ballasts have on the power quality of the buildings being retrofit, studies are being performed at three buildings scheduled for the retrofit program. Power quality measurements throughout the buildings are being made before, during, and after the lighting retrofits. The results will be analyzed and simulations performed to identify and predict power quality problems that might occur with these and future retrofits. The effect of electronic ballasts on sensitive electronic devices is under investigation. Electronic ballasts are attributed with causing interference in a hearing aid worn by a student in an elementary school and interference with a book detector in a library. The effects are being studied to determine and understand the mechanism and recommend solutions to rectify the problems.

Title: Transient Effects of PWM ASDs on Standard Squirrel Cage Induction Motors Authors: Melhorn, Christopher J., Le Tang Date: October, 1995 Conference: 1995 IEEE IAS Annual Technical Conference Abstract: With the advances in semi-conductor devices, adjustable speed drives (ASDs) have become more prevalent than ever before in industrial and commercial processes. Many facilities are installing ASDs to improve the efficiency of their processes and to increase the control of their processes. While the effects of ASDs on the power system are well known, many engineers and systems integrators are not aware of the effects that ASDs can have on the motor that is driven by the drive. This paper describes the techniques used to measure, analyze, and simulate the problems associated with the use of PWM ASDs to drive induction motors. Measures to mitigate these problems are also discussed. The Electro-Magnetic Transients Program (EMTP) is used to simulate the phenomena, compare results against measurements, and evaluate mitigation techniques.

Title: Voltage Sags: Their Impact on the Utility and Industrial Customers Authors: Davis, Tim, George Beam, Christopher J. Melhorn Date: May, 1995 Conference: PQA 95 Conference Abstract: This paper describes the impact of voltage sags on the utility and industrial customers. Several utility measures are presented to minimize the customer's exposure to voltage sags. However, these measures cannot completely eliminate the impact of voltage sags on sensitive equipment. A case study is presented in this paper that includes measurement results that were used to characterize the voltage sags experienced on the utility system and in the industrial facility, simulation results that were used to develop “area of vulnerability curves” for the industrial facility, mitigation equipment that was employed to improve the sensitive equipment’s ride through capability, and the lessons learned from the systems approach analysis.

Title: An Evaluation of Energy Storage Techniques for Improving Ride-Through Capability for Sensitive Customer on Underground Networks Authors: Braz, Aubrey, Peter Hofmann, Ralph Mauro, Christopher J. Melhorn Date: May, 1995 Conference: PQA 95 Conference Abstract: Most Con Edison customers are supplied through extensive network systems. These customers do not experience interruptions or outages except under very rare circumstances. This is a significant advantage for these customers since they do not normally need to apply energy storage systems for protection of critical loads. However, voltage sags, which occur whenever there is a fault on the power system, can affect the important loads. The sensitivity of some critical loads can cause dropout or mis-operation during voltage sag conditions. Some type of protection may be needed for these loads to provide ride through support during voltage sags. This paper describes the methodology used in a research project sponsored by EPRI and Con Edison to evaluate the need for voltage sag ride through improvement for the selected customers. Technologies that can supply the required ride through were evaluated and application considerations were developed. Two case studies are presented in this paper to illustrate the methodolgy used to perform the evaluations.

Title: Transient Effects of PWM Drives on Induction Motors Authors: Melhorn, Christopher J., Le Tang Date: May, 1995 Conference: 1995 IEEE/IAS Industrial and Commercial Power Systems Conference Abstract: With the advances in semi-conductor devices, adjustable speed drives (ASDs) have become more prevalent than ever before in industrial and commercial processes. Many facilities are installing ASDs to improve the efficiency of their processes and to increase the control of their processes. While the effects of ASDs on the power system are well known, many engineers and systems integrators are not aware of the effects that ASDs can have on the motor that is driven by the drive. This paper describes the techniques used to measure, analyze, and simulate the problems associated with the use of PWM ASDs to drive induction motors. Measures to mitigate these problems are also discussed. The Electro-Magnetic Transients Program (EMTP) is used to simulate the phenomena, compare results against measurements, and evaluate mitigation techniques.

Title: Interpretation and Analysis of Power Quality Measurements Authors: Melhorn, Christopher J., Mark McGranaghan Date: May, 1995 Conference: 1995 IEEE/IAS Textile, Fiber and Film Conference Abstract: This paper describes advances in power quality monitoring equipment and software tools for analyzing power quality measurement results. Power quality monitoring has advanced from strictly problem solving to ongoing monitoring of system performance. The increased amount of data being collected requires more advanced analysis tools. Types of power quality variations are described and the methods of characterizing each type with measurements are presented. Finally, methods for summarizing the information and presenting it in useful report formats are described.

Title: Effects of PWM ASDs on Standard Squirrel Cage Induction Motors Authors: Melhorn, Christopher J., Le Tang Date: September, 1994 Conference: 1994 Power Quality/PCIM Conference Abstract:

Title: Electromagnetic Susceptibility of Electronic Devices to High Efficiency Electronic Lighting Authors: Schwabe, R.J., Z. Zelingher, T. Key, K. Phipps, C.J. Melhorn, S. Williams Date: October, 1994 Conference: PQA94 Conference Abstract:

Title: Characterization of Power Quality Problems Associated with Large Commercial Customers Served from Large Underground Distribution Network Systems Authors: Melhorn, Christopher J., Peter Hofmann, Aubrey Braz, Marek Samotyj Date: May, 1994 Conference: 1994 IEEE IAS Industrial and Commercial Power Systems Conference Abstract: The ever increasing utilization of sensitive electronic loads for productivity and energy efficiency improvements make the characterization of power quality supplied by the electric utility a growing concern. This paper describes the results of a project designed to characterize the power quality supplied to various classes of large commercial customers on the network distribution systems in Manhattan. The effects of power quality on the operation of different types of commercial facilities is also discussed. Items addressed include long term voltage regulation, voltage sags due to system faults, and harmonic distortion caused by end user loads.

Title: Commercial Building Harmonics - Impact of Electronic Ballasts Authors: Schwabe, R.J., C.J. Melhorn Date: January, 1994 Conference: 1994 IEEE PES Winter Power Meeting, Panel Session on Harmonics Abstract:

Title: Operational and Harmonic Concerns Associated with a Semiconverter Authors: Tang, Le, Christopher J. Melhorn Date: April, 1994 Conference: 1994 IEEE IAS Rubber and Plastics Conference Abstract: This paper clarified the harmonic problem associated with applications of a semiconverter. A comprehensive explanation of the harmonic generation and the analyses of converter operation with different firing angles were provided. Voltage and current waveforms showing the distortion characteristics of the input and output quantities are presented. The performance of an installed 2nd harmonic filter to reduce even harmonic injection into the system and to improve circuit power factor was evaluated using Electromagnetic Transient Program.

Title: Effect of High Efficiency Lighting on Power Quality in Public Buildings Authors: Schwabe, R.J., C.J. Melhorn, M. Samotyj Date: November, 1993 Conference: PQA93 Conference Abstract: The New York Power Authority (NYPA) is currently implementing a High Efficiency Lighting Program (HELP) in schools and public buildings within the State of New York. HELP focuses on the replacement of magnetic ballast fluorescent light fixtures with the new high efficiency electronic ballast fixtures. The use of electronic ballast can have an adverse effect on power quality. To determine the effects that the electronic ballasts have on the power quality of the buildings being retrofit, studies are being performed at three buildings scheduled for the retrofit program. Power quality measurements throughout the buildings are being made before, during, and after the lighting retrofits. The results will be analyzed and simulations performed to identify and predict power quality problems that might occur with these and future retrofits. The effect of electronic ballasts on sensitive electronic devices is under investigation. Electronic ballasts are attributed with causing interference in a hearing aid worn by a student in an elementary school and interference with a book detector in a library. The effects are being studied to determine and understand the mechanism and recommend solutions to rectify the problems.

Title: Power Quality Case Studies Voltage Sags; The Impact on the Utility and Industrial Customers Authors: Beam, G.E., E.G. Dolack, C.J. Melhorn, V. Misiewicz, M. Samotyj Date: November, 1993 Conference: PQA93 Conference Abstract: This paper describes the impact of voltage sags on the utility and the customer's equipment. Several utility measures are presented to minimize the customer's exposure to voltage sags. However, these measures cannot completely eliminate the impact of voltage sags on sensitive equipment. Additional measures taken on the customer side are presented. These measures were incorporated to minimize the impacts of voltage sags on the customer. In this case study, the lessons learned from the systems approach analysis can be applied to resolve a wide range of voltage sag problems.

Title: Design of a Measurement Program to Characterize Distribution Power Quality. Proceedings Authors: Markel, L.C., C.J. Melhorn, S.R. Williams, H. Mehta Date: May, 1993 Conference: 12th International Conference on Electricity Distribution (CIRED’93) Abstract: This paper describes the design of a sampling and measurement program (sponsored by the Electric Power Research Institute, RP3098-1) to characterize distribution power quality in the United States. The program involves placing 300 monitors on sites in 25 utilities over a 2 year period. The first step of the program was to determine what quantities should be measured and which sites to monitor. In selecting sites, we needed to be sure we covered the range of power quality conditions in the United States, but that the sample would be unbiased. Because of the large number of utilities involved, the challenge was to avoid being burdensome to the utilities by collecting too much site-specific data to represent the "universe" of United States distribution systems, while maintaining the precision and statistical validity required in the resulting measurements.

Title: Does Your Watt-hour Meter Play the Harmonic(a)? Authors: Melhorn, Christopher J., Thomas Levitsky Date: October, 1989 Conference: IEEE Student Paper Contest - Region 2 Abstract: