CHAPTER 1: INTRODUCTION What is Power Quality? Power Quality -- Voltage Quality Why Are We Concerned About Power Quality? The Power Quality Evaluation Procedure Who Should Use This Book Overview of the Contents CHAPTER 2: TERMS AND DEFINITIONS Need for a Consistent Vocabulary General Classes of Power Quality Problems Transients Long-Duration Voltage Variations Short-Duration Voltage Variations Voltage Imbalance Waveform Distortion Voltage Fluctuation Power Frequency Variations Power Quality Terms Ambiguous Terms CBEMA and ITI Curves References CHAPTER 3: VOLTAGE SAGS AND INTERRUPTIONS Sources of Sags and Interruptions Estimating Voltage Sag Performance Fundamental Principles of Protection Solutions at the End-User Level Evaluating the Economics of Different Ride-Through Alternatives Motor-Starting Sags Utility System Fault-Clearing Issues References CHAPTER 4: TRANSIENT OVERVOLTAGES Sources of Transient Overvoltages Principles of Overvoltage Protection Devices for Overvoltage Protection Utility Capacitor-Switching Transients Utility System Lightning Protection Managing Ferroresonance Switching Transient Problems with Loads Computer Tools for Transients Analysis References CHAPTER 5: FUNDAMENTALS OF HARMONICS Harmonic Distortion Voltage versus Current Distortion Harmonics versus Transients Harmonic Indexes Harmonic Sources from Commercial Loads Harmonic Sources from Industrial Loads Locating Harmonic Sources System Response Characteristics Effects of Harmonic Distortion Interharmonics References Bibliography CHAPTER 6: APPLIED HARMONICS Harmonic Distortion Evaluations Principles for Controlling Harmonics Where to Control Harmonics Harmonic Studies Devices for Controlling Harmonic Distortion Harmonic Filter Design: A Case Study Case Studies Standards of Harmonics References Bibliography CHAPTER 7: LONG-DURATION VOLTAGE VARIATIONS Principles of Regulating the Voltage Devices for Voltage Regulation Utility Voltage Regulator Application Capacitors for Voltage Regulation End-User Capacitor Application Regulating Utility Voltage with Distributed Resources Flicker References Bibliography CHAPTER 8: POWER QUALITY BENCHMARKING Introduction Benchmarking Process RMS Voltage Variation Indices Harmonics Indices Power Quality Contracts Power Quality Insurance Power Quality State Estimation Including Power Quality in Distribution Planning References Bibliography CHAPTER 9: DISTRIBUTED GENERATION AND POWER QUALITY Resurgence of DG DG Technologies Interface to the Utility System Power Quality Issues Operating Conflicts DG on Distribution Networks Siting DGDistributed Generation Interconnection Standards Summary References Bibliography CHAPTER 10: WIRING AND GROUNDING Resources Definitions Reasons for Grounding Typical Wiring and Grounding Problems Solutions to Wiring and Grounding Problems Bibliography CHAPTER 11: POWER QUALITY MONITORING Monitoring Considerations Historical Perspective of Power Quality Measuring Instruments Power Quality Measurement Equipment Assessment of Power Quality Measurement Data Application of Intelligent Systems Power Quality Monitoring Standards References Index INDEX

Electrical Power Systems Quality

The future penetration of electric vehicles into the transportation sector is unknown. However, if off peak recharging of electric vehicles is employed, considerable improvement in daily load factor is possible. Similarly, load management methods to shift peak load to off-peak periods will also improve load factor. The impact of electric vehicle deployment on load management strategies primarily occurs in two areas: (i) reduction in effectiveness of load factor improvement of either electric vehicle deployment or load management strategies due to the action of the other and (ii) inadvertent addition to peak demand by electric vehicle load. These and other factors are considered in this paper and several practical considerations of recharging of electric vehicles are summarized.

The Impact of Electric Vehicle Deployment on Load Management Straregies

A growing number of harmonic mitigation techniques are now available including active and passive methods, and the selection of the best-suited technique for a particular case can be a complicated decision-making process. The performance of some of these techniques is largely dependent on system conditions, while others require extensive system analysis to prevent resonance problems and capacitor failure. A classification of the various available harmonic mitigation techniques is presented in this paper aimed at presenting a review of harmonic mitigation methods to researchers, designers, and engineers dealing with power distribution systems.

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Harmonic Mitigation Techniques Applied to Power Distribution Networks

This paper presents a survey of voltage and current harmonic distortion levels at 40 power transformers and 10 power capacitor units in Northern Taiwan Through one year of measurements, about 12,000 sets of harmonic voltage and current data were recorded and analyzed The types and levels of harmonics are shown in each power transformer which supplies different residential, commercial and industrial customers with various loads At the same time, a suggestion is given to the representative value of the background level of harmonic voltages with 95% cumulative probability which is adopted by Taipower In conclusion, the effects of harmonics on capacitors and power transformers are discussed

Survey of harmonic voltage and current at distribution substation in Northern Taiwan

A survey of current and voltage distortion levels measured at 76 different sites is presented. Over 5000 pairs of current and voltage waveforms were recorded and analyzed for this study. In addition to summarizing the harmonic levels at the various industrial, commercial, and substation sites, the authors use data at a particular nonlinear load site to show how US utilities may be failing to collect the correct revenues from power factor penalty clauses. The instrumentation used to collect the field data is briefly described. The results of the field measurements are discussed, with particular emphasis on the problem sites identified during the project. >

Survey of harmonic levels on the Southwestern Electric Power Company system

This paper describes the instrumentation systems and test methodologies used for simultaneously measuring voltage and current harmonic magnitudes at the harmonic source and remote-feeder locations on each of two distribution systems. Results of two sets of field tests are presented. Recommendations are offered for measuring distribution system harmonics.

Measuring Voltage and Current Harmonics on Distribution Systems

Because of the anticipated applicaton of large ac/dc power converters on utility distribution systems, the Electric Power Research Institute (EPRI) funded Project RP1024-1 to study distribution system surge and harmonic characteristics. The harmonics produced by large converters depends on converter type (line-or self-commutated), converter pulse number, thyristor firing angle controls, commutation angles, voltage regulation techniques, voltage unbalance, and?very importantly?network impedance frequency response. Of particular significance is the fact that a great deal of effort is still required to determine tolerable levels of harmonic voltages and currents on distribution systems. Harmonic controls for power converters-important because of their effect on converter cost and efficiency-are now specified on the basis of engineering data which need to be enhanced by further testing and analysis. In the face of observable and ever-increasing background levels of distribution system harmonics, more precise anticipation of future concerns is required. Test methods and instrumentation need to be standardized to ensure conformance to yet-to- be-determined permissible harmonic limits. This paper discusses line-and self-commutated power converters and techniques for controlling the harmonics associated with them and presents the principal results of EPRI Project RP1024-1.

Distribution System Harmonics: Controls for Large Power Converters

Impulsive noise measurements were made on two electric distribution systems as part of Electric Power Research Institute Project RP1024-1, Study of Distribution System Surge and Harmonic Characteristics. This paper describes the instrumentation system used to measure impulsive noise conducted along, and emanated from, distribution lines in the 3-300-kHz frequency band. A significant source of this noise was identified as synchronously switched power converters. The concern is that such noise on distribution systems might cause interference to digital data carrier systems proposed for distribution systems. Test data from one of the utility systems are presented; potential problems caused by interference are discussed. Additional work utilizing the same or similar instrumentation on a relatively broad spectrum of distribution systems is recommended to identify and characterize impulsive noise.

R. E. Owen

Papers

Measuring Voltage and Current Harmonics on Distribution Systems

Distribution System Harmonics: Controls for Large Power Converters

Measurement of Impulsive Noise on Electric Distribution Systems