The advent of low temperature superconductors in the early 1960's converted what had been a laboratory curiosity with very limited possibilities to a prac tical means of fabricating electrical components and devices with lossless con ductors. Using liquid helium as a coolant, the successful construction and operation of high field strength magnet systems, alternators, motors and trans mission lines was announced. These developments ushered in the era of what may be termed cryogenic power engineering and a decade later successful oper ating systems could be found such as the 5 T saddle magnet designed and built in the United States by the Argonne National Laboratory and installed on an experimental power generating facility at the High Temperature Institute in Moscow, Russia. The field of digital computers provided an incentive of a quite different kind to operate at cryogenic temperatures. In this case, the objective was to ob tain higher switching speeds than are possible at ambient temperatures with the critical issue being the operating characteristics of semiconductor switches under cryogenic conditions. By 1980, cryogenic electronics was established as another branch of electric engineering.

Device and Circuit Cryogenic Operation for Low Temperature Electronics is a first in reviewing the performance and physical mechanisms of advanced devices and circuits at cryogenic temperatures that can be used for many applications. The first two chapters cover bulk silicon and SOI MOSFETs. The electronic transport in the inversion layer, the influence of impurity freeze-out, the special electrical properties of SOI structures, the device reliability and the interest of a low temperature operation for the ultimate integration of silicon down to nanometer dimensions are described. The next two chapters deal with Silicon-Germanium and III-V Heterojunction Bipolar Transistors, as well as III-V High Electron Mobility Transistors (HEMT). The basic physics of the SiGe HBT and its unique cryogenic capabilities, the optimization of such bipolar devices, and the performance of SiGe HBT BiCMOS technology at liquid nitrogen temperature are examined. The physical effects in III-V semiconductors at low temperature, the HEMT and HBT static, high frequency and noise properties, and the comparison of various cooled III-V devices are also addressed. The next chapter treats quantum effect devices made of silicon materials. The major quantum effects at low temperature, quantum wires, quantum dots as well as single electron devices and applications are investigated. The last chapter overviews the performances of cryogenic circuits and their applications. The low temperature properties and performance of inverters, multipliers, adders, operational amplifiers, memories, microprocessors, imaging devices, circuits and systems, sensors and read-out circuits are analyzed. Device and Circuit Cryogenic Operation for Low Temperature Electronics is useful for researchers, engineers, Ph.D. and M.S. students working in the field of advanced electron devices and circuits, new semiconductor materials, and low temperature electronics and physics.

In recent years, the technology of cryogenic comminution has been widely applied in the field of chemical engineering, food making, medicine production, and particularly in recycling of waste materials. Because of the increasing pollution of waste tires and the shortage of raw rubber resource, the recycling process for waste rubber products has become important and commercially viable. This technology has shown a great number of advantages such as causing no environmental pollution, requiring low energy consumption and producing high quality products. Hence, the normal crusher which was used to reclaim materials, such as waste tires, nylon, plastic and many polymer materials at atmospheric 12 temperature is being replaced by a cryogenic crusher. • In the cryogenic crusher, the property of the milled material is usually very sensitive to temperature change. When a crusher is in operation, it will generate a great deal of heat that causes the material temperature increased. Once the temperature increases over the vitrification temperature, the material property will change and lose the brittle behavior causing the energy consumption to rise sharply. Consequently, the comminution process cannot be continued. Therefore, it is believed that the cryogenic crusher is the most critical component in the cryogenic comminution system. The research on the temperature increase and energy consumption in the cryogenic crusher is not only to reduce the energy consumption of the crasher, but also to reduce the energy consumption of the cryogenic system.

One of the main trend in the development of high power electric machines (motors, generators) is to replace the magnetic components with superconducting wires, this inevitably leads to a critical requirement from the industry (Converteam) to operate power devices at cryogenic temperatures. However, the current understanding of the behaviour power devices at cryogenic temperatures is limited, especially below the liquid nitrogen temperature of 77 K. This is a problem since most of the superconducting wires operate at temperatures below 77 K. Furthermore, it is uncertain which device type is better, if at all suited to cryogenic operation. In order to answer this, a thorough analysis of the known cryogenic behaviour of all the generic power devices was performed, including the physical behaviour of silicon at cryogenic temperatures. It is concluded that the power MOSFET is the best likely candidate for cryogenic operation. To understand the cryogenic behaviour of silicon power MOSFETs especially between the temperatures of 20 K and 100 K, a cryogenic measurement system was built to characterise different types of power MOSFETs. All the measured power MOSFETs exhibited large improvement in on-state resistance down to 50 K and non-linear degradation of breakdown voltages with lower temperatures. Various behaviour was observed below 50 K including carrier freeze-out, electric field dependent ionisation of free charge carriers and large variations in on-state resistance between identical devices. Several power Schottky diodes were also characterised and all exhibited merged PiN Schottky diode behaviour at cryogenic temperatures. Non-silicon devices such as silicon carbide power MOSFETs and gallium nitride HEMTs were also measured. Silicon carbide exhibited no improvements at cryogenic temperatures, whereas gallium nitride HEMTs may prove to be the best power device to be utilised in future cryogenic applications. Since unusual behaviour was observed in power MOSFETs below 50 K, an attempt was made to explain these phenomena using theoretical equations of semiconductor physics and analytical models of power MOSFETs. The author suggested that careful control of the dopant concentration at the accumulation region below the oxide gate is required to improve the power MOSFET operations below 50 K. Moreover, the super-junction power MOSFETs could be optimised for better cryogenic operation. It is the intention of this work to demonstrate the benefits of power MOSFET cryogenic operation in a realistic industrial application. A demonstration model was designed and simulated, this circuit uses a back-to-back power MOSFETs configuration to control the freewheeling current flowing through a high temperature superconducting coil. The electrical and thermal design of the model has been described, simulated and presented in this work.

What are the benefits of electrified propulsion for large aircraft? What technology advancements are required to realize these benefits? How can the aerospace industry transition from today's technologies to state-of-the-art electrified systems? Learn the answers with this multidisciplinary text, combining expertise from leading researchers in electrified aircraft propulsion. The book includes broad coverage of electrification technologies – spanning power systems and power electronics, materials science, superconductivity and cryogenics, thermal management, battery chemistry, system design, and system optimization – and a clear-cut road map identifying remaining gaps between the current state-of-the-art and future performance technologies. Providing expert guidance on areas for future research and investment and an ideal introduction to cutting-edge advances and outstanding challenges in large electric aircraft design, this is a perfect resource for graduate students, researchers, electrical and aeronautical engineers, policymakers, and management professionals interested in next-generation commercial flight technologies.

Power Quality Enhancement Using Custom Power Devices considers the structure, control and performance of series compensating DVR, the shunt DSTATCOM and the shunt with series UPQC for power quality improvement in electricity distribution. Also addressed are other power electronic devices for improving power quality in Solid State Transfer Switches and Fault Current Limiters. Applications for these technologies as they relate to compensating busses supplied by a weak line and for distributed generation connections in rural networks, are included. In depth treatment of inverters to achieve voltage support, voltage balancing, harmonic suppression and transient suppression in realistic network environments are also covered. New material on the potential for shunt and series compensation which emphasizes the importance of control design has been introduced.

The IGBT device has proved to be a highly important Power Semiconductor, providing the basis for adjustable speed motor drives (used in air conditioning and refrigeration and railway locomotives), electronic ignition systems for gasolinepowered motor vehicles and energy-saving compact fluorescent light bulbs. Recent applications include plasma displays (flat-screen TVs) and electric power transmission systems, alternative energy systems and energy storage. This book is the first available to cover the applications of the IGBT, and provide the essential information needed by applications engineers to design new products using the device, in sectors including consumer, industrial, lighting, transportation, medical and renewable energy. The author, B. Jayant Baliga, invented the IGBT in 1980 while working for GE. His book will unlock IGBT for a new generation of engineering applications, making it essential reading for a wide audience of electrical engineers and design engineers, as well as an important publication for semiconductor specialists. - Essential design information for applications engineers utilizing IGBTs in the consumer, industrial, lighting, transportation, medical and renewable energy sectors. - Readers will learn the methodology for the design of IGBT chips including edge terminations, cell topologies, gate layouts, and integrated current sensors. - The first book to cover applications of the IGBT, a device manufactured around the world by more than a dozen companies with sales exceeding $5 Billion; written by the inventor of the device.

Deregulation is a fairly new paradigm in the electric power industry. And just as in the case of other industries where it has been introduced, the goal of deregulation is to enhance competition and bring consumers new choices and economic benefits. The process has, obviously, necessitated reformulation of established models of power system operation and control activities. Similarly, issues such as system reliability, control, security and power quality in this new environment have come in for scrutiny and debate. In this book, we attempt to present a comprehensive overview of the deregulation process that has developed till now, focussing on the operation aspects. As of now, restructured electricity markets have been established in various degrees and forms in many countries. This book comes at a time when the deregulation process is poised to undergo further rapid advancements. It is envisaged that the reader will benefit by way of an enhanced understanding of power system operations in the conventional vertically integrated environment vis-a-vis the deregulated environment. The book is aimed at a wide range of audience- electric utility personnel involved in scheduling, dispatch, grid operations and related activities, personnel involved in energy trading businesses and electricity markets, institutions involved in energy sector financing. Power engineers, energy economists, researchers in utilities and universities should find the treatment of mathematical models as well as emphasis on recent research work helpful.

`Electric energy must be treated as a commodity which can be bought, sold, and traded, taking into account its time- and space-varying values and costs.` Spot Pricing of Electricity, Schweppe et al, 1988. Computational Auction Mechanisms for Restructured Power Industry Operation outlines the application of auction methods for all aspects of power system operation, primarily for a competitive environment. A complete description of the industry structure as well as the various markets now being formed is given. A thorough introduction to auction basics is included to explain how auctions have grown in other industries. Auction methods are compared to classical techniques for power system analysis, operations, and planning. The traditional applications of economic dispatch, optimal power flow and unit commitment are compared to auction mechanisms. Algorithms for auctions using linearized power flow equations, DC power flow equations, and AC power flow equations are included. The bundling of supportive services, known as ancillary services within the United States, is discussed. Extensions to the basic auction algorithms for inclusion of supportive services as well as algorithms for scheduling and bidding on generation for GENCOs or independent power producers are presented. Algorithms for scheduling and contracting with customers are also presented for energy service companies. An introduction to the various commodity and financial market products includes the use of futures and options for GENCOs. The material is useful for students performing research on the new business environment based on competition. Regulators will find information on initial methods of designing and evaluating market systems, and power exchange and financial analysts will find information on the interdependence of markets and power system-based techniques for risk management. This information compares the new business environment solutions with old business environment solutions. Computational Auction Mechanisms for Restructured Power Industry Operation provides a first introduction to how electricity will be traded as a commodity in the future.