Power electronics in German railway propulsion
Article Abstract:
Power electronic systems pushed the development of advanced railroad propulsion systems and have replaced mechanical step-switched drive systems. Basic requirements of such propulsion systems vary but include smooth torque, fine control, torque levels varying per application, very low power in systems with long overhead power lines, and electrical breaking in traction drives. Power electronic devices include: line commutated rectifiers for dc motor propulsion, dc supply choppers for non-dissipative control, current source inverters for squirrel-cage and synchronous motors, and voltage source inverters. High-power voltage source inverters feeding squirrel-cage motors are standard in traction applications and the configuration, use of pulse-width modulation controls, machine control circuitry, DC link input, and use in high power locomotive systems are described.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1988
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Power electronics in the minicomputer industry
Article Abstract:
The design of minicomputer power systems is driven by the need to account for variations in power sources, loads, evolving large-scale digital ICs, efficient, small switching power technologies, and by market and regulatory demands. Any specific power solution is predicated on two factors: it must accommodate the computer's performance requirements, and it is a function of available and appropriate circuit, component, cooling, and packaging technologies. Typical design solutions and strategies for current portable computers, desktop workstations, rack-mount systems, and superminicomputers are described. Major goals in current power system research are to reduce the size and cost of power conversion subsystems. Specific technical goals are the achievement of higher switching frequencies, higher levels of integration, and improved thermal performance.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1988
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Life after the schematic: the impact of circuit operation on the physical realization of electronic power supplies
Article Abstract:
Power electronic circuits are schematically simpler than comparably-sized digital circuits, but the non-linear analog operation of switching power systems, varying circuit time constants, high accuracy of switching instants, and consequent complexity of circuit analysis and physical layout make most computer-aided design tools unsuitable. Resolving analytic complexity requires ensuring that electrical design goals are represented in an error-free schematic, but the non-linear equations are too difficult to solve with speed and accuracy in computer simulations. Verifying the physical layout is beyond current simulation systems because of the sensitivity of circuit design to layout-induced parasitic elements. A viable design strategy is to first focus on layout followed by schematics. Ways of optimizing design process management are described.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1988
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