The Vacuum Interrupter


Book Description

Title: The Vacuum Interrupter: Theory, Design, and Application Shelving guide: Electrical Engineering Dr. Paul Slade draws from his nearly six decades of active experience to develop this second edition of The Vacuum Interrupter: Theory, Design, and Application. This book begins by discussing the design requirements for high voltage vacuum interrupters and then the contact requirements to interrupt the vacuum arc. It then continues by describing the various applications in which the vacuum interrupter is generally utilized. Part 1 of this book begins with a detailed review of the vacuum breakdown process. It continues by covering the steps necessary for the design and the manufacture of a successful vacuum interrupter. The vacuum arc is then discussed, including how it is affected as a function of current. An overview of the development and use of practical contact materials, along with their advantages and disadvantages, follows. Contact designs that are introduced to control the high current vacuum arc are also analyzed. Part 2, on application, begins with a discussion of the arc interruption process for low current and high current vacuum arcs. It examines the voltage escalation phenomenon that can occur when interrupting inductive circuits. The occurrence of contact welding for closed contacts subjected to the passage of high currents, and for contacts when closing on high currents, is explored. The general requirements for the successful manufacture and testing of vacuum circuit breakers is then presented. The general application of vacuum interrupters to switch load currents, especially when applied to capacitor circuits, is also given. The interruption of high short circuit currents is presented along with the expected performance of the two major contact designs. Owing to the ever-increasing need for environmentally friendly circuit protection devices, the development and application of the vacuum interrupter will only increase in the future. At present the vacuum circuit breaker is the technology of choice for distribution circuits (5kV to 40.5kV). It is increasingly being applied to transmission circuits (72.5kV to 242kV). In the future, its application for protecting high voltage DC networks is assured. Audience This is a practical source book for engineers and scientists interested in studying the development and application of the vacuum interrupter Research scientists in industry and universities Graduate students beginning their study of vacuum interrupter phenomena Design engineers applying vacuum interrupters in vacuum switches, vacuum contactors, vacuum circuit breakers, and vacuum contactors It provides a unique and comprehensive review of all aspects of vacuum interrupter technology for those new to the subject and for those who wish to obtain a deeper understanding of its science and application Scientists and engineers, who are beginning their research into vacuum breakdown and aspects of the vacuum arc, will find the extensive bibliography and phenomenological descriptions to be a useful introduction




The Vacuum Interrupter


Book Description

Drawn from the author's more than four decades of practical experience in the industry, The Vacuum Interrupter: Theory, Design, and Application first discusses the design and manufacture of the vacuum interrupter before delving into its general application. The book begins with a review of the vacuum breakdown process and what to consider when developing a design for a high-voltage application. It then discusses the vacuum arc and how its appearance changes as a function of current. This section concludes with an overview of existing contact materials, a summary of their advantages and disadvantages, an analysis of vacuum interrupter contact design, and considerations for the manufacture of vacuum interrupters. The next section on application describes the interruption process for low- and high-current vacuum arcs, examines the voltage escalation event that occurs if the contact gap is very small at the ac current zero, and explores the phenomenon of contact welding. It also studies the application of vacuum interrupters to switch load currents, circuit breakers, and reclosers. Owing to the increasing need for environmentally friendly interrupting systems, the development of vacuum interrupters will only intensify over time. With extensive references in each chapter for further exploration, this comprehensive guide provides essential, up-to-date knowledge to fully understand this vital technology.




Vacuum Interrupters and Thyratrons as Opening Switches


Book Description

The clear advantages of inductive storage for large scale energy storage applications are creating an increasing interest in the research and development of the opening switches required. Opening switches for single-shot inductive transfers have received considerable attention and are fairly well advanced. The problem addressed by this workshop of high power opening switches for high repetition rate applications is much more severe, however, and may well require a major research and development effort. Two candidates for such an opening switch, the triggered vacuum interrupter and the magnetically quenched thyratron, are discussed. By electrically retriggering the discharge in the vacuum interrupter between pulses, the dependence on mechanical motion is eliminated. This should enable repetition rate operation at 10 to 15 kHz while still maintaining the vacuum interrupter's proven interrupting performance of tens of kiloamps at tens of kilovolts. The magnetically quenched thyratron, on the other hand, uses a cross magnetic field to raise the switch impedance by decreasing the electron mobility and driving the discharge into an arc chute wall where it is quenched. Successful interruptions of 1 kA at 15 kV and 100 A at 50 kV after conduction for 10 .mu.s have been demonstrated by previous researchers. Work at Los Alamos is directed toward understanding the basic mechanisms involved and increasing the switch ratings, particularly the conduction time.




Vacuum Switchgear


Book Description

Drawing from his 40 years of experience in the field, Greenwood (engineering, Rensselaer Polytechnic) describes the development of vacuum switchgear technology from its earliest origins to the most recent designs now offered by companies around the world. The volume begins with a foundation in the physics of the vacuum arc, in vacuum breakdown, and in the fundamentals of current interruption in vacuum. A chapter on applications spans all devices from contactors through switches and reclosers to power circuit breakers. Maintenance is also addressed. There are four chapters on different aspects of design and another on testing. The chapter on manufacturing concentrates on the interrupter as its manufacture is so entirely different from that required for oil and gas-blast circuit breakers. Thoroughly illustrated. Distributed by INSPEC. Annotation copyright by Book News, Inc., Portland, OR




Opening Switches


Book Description

Pulsed power technology, in the simplest of terms, usually concerns the storage of electrical energy over relatively long times and then its rapid release over a comparatively short period. However, if we leave the definition at that, we miss a multitude of aspects that are important in the ultimate application of pulsed power. It is, in fact, the application of pulsed power technology to which this series of texts will be foc~sed. Pulsed power in today's broader sense means "special power" as opposed to the traditional situation of high voltage impulse issues related to the utility industry. Since the pulsed power field is primarily application driven it has principally engineering flavor. Today's applications span those from materials processing, such as metal forming by pulsed magnetic fields, to commercial applications, such as psychedelic strobe lights or radar modulators. Very high peak power applica tions occur in research for inertial confinement fusion and the Strategic Defense Initiative and other historical defense uses. In fact it is from this latter direction that pulsed power has real ized explosive growth over the past half century. Early thrusts were in electrically powered systems that simulated the environment or effects of nuclear weapons detonation. More recently it is being utilized as prime power sources for directed energy weapons, such as lasers, microwaves, particle beam weapons, and even mass drivers (kinetic energy weapons).













Vacuum Arcs


Book Description

Leading experts examine the theory, principles, and recent applications of vacuum arc devices, with special attention to the intensive research and development on the high-power vacuum circuit interrupter conducted at the General Electric Research and Development Center. Covers all important aspects of vacuum discharges: the wide variety of breakdown processes; Arc ignition by plasma triggering; the arc cathode; the emission process at the arc anode; high-current anode processes; and commercial and non-commercial applications of vacuum interrupters.