 |
 |
EPE Journal Volume 03-2 - Papers
- Space Power Electronics, Design Drivers (I)
- Synchrotron Magnet Power Supplies
- Imbricated cells Multi-Level Voltage-Source Inverters for High Voltage Applications
- Using SEPIC Topology for Improving Power Factor in Distributed Power Supply Systems
- Wide Bandwidth Rogowski Current Transducers: Part II - The Integrator
EPE Journal Volume 03-2 - Editorial
By R. M. Davis
The Editorial of the EPE Journal Volume 3 N°2, "EPE '93 Conference", written by R. M. Davis, the Chairman of the EPE '93 Conference and Founding Member of EPE Association.
EPE Journal Volume 03-2 - Papers
By D. O'Sullivan
In order to undestand the key differences between space and industrial power electronics, it is essential that those features that are unique to the space environment are clearly identified.
In the first part of this paper those key drivers that effect the choice of design approach will be described and the remainder of the paper will illustrate how these drivers effect the choice of regulator topologies and the overall approach to power system design.
The second part of this paper can be found in EPE Journal Volume 1993-3 and the third part in EPE Journal Volume 1993-4.
By K. Bouwknegt
The DC power supplies for bending and focusing magnets of a typical large particle accelerator present special problems in the field of power electronics. Although they are in principal thyristor rectifiers in the kW to MW range, the rapid cycling and precise control of the output voltage and current call for unusual arrangements of thyristor bridges, and for postregulation to combine speed with a ripple free, highly accurate output.
By T. A. Meynard; H. Foch
In the field of High Voltage Power Conversion, various techniques have been developped to use series-connected switches.
Plain series connection of switches is the first solution and its drawbacks are now well-known (static and dynamic voltage sharing difficulties that require selecting paired switches or using sophisticated control techniques, high dV/dts generated by the synchronous commutation of all the switches, output waveform that does not benefit from the increased number of switches,...)
The "neutral point clamped" technique introduced in the early '80s improves voltage sharing and dV/dts, and gives a three-level output waveform.
More recently a new multilevel topology has been introduced; compared to former techniques, it really solves the problem of voltage sharing and dV/dts, and gives a three-level output waveform with cancellation of the harmonic and the switching frequency.
In this paper, it is shown that this technique can be easily generalized to voltage-source inveter legs with any number of switches, that these inverter legs can operate under any power factor condition (and especially in the rectifier mode as well as in the inverter mode) and that these legs can be used in half-bridge, full-bridge, or three-phase voltage-source inverters.
Experimental results of a 1.5 kV, 20 A, 48 kHz IGBT line-operated rectifier with sinusoidal input current are given.
By J. Sebastián; J. Uceda; J. A. Cobos; J. Arau
The Single Ended Primary Inductance Converter (SEPIC) presents several advantages over boost and flyback topologies which make this converter very convenient to be used as Power Factor Preregulator (PFP), specially in distributed power supply systems. Due to this fact, the PWM SEPIC used as PFP is studied in this paper. Stress in components and operation in continuous and discontinuous conduction mode are considered in this paper. The study reveals that both types of PFP control (multiplier approach and voltage-follower approach) can be used in PWM SEPIC, the first one when it operates in continuous conduction mode and the second one when it operates in discontinuous conduction mode. Finally the theoretical analysis is validated in two prototypes (continuous and discontinuous conduction mode).
By W. F. Ray
This paper is the second of three parts giving a comprehensive examination of the use of Rogowski coils for wide bandwidth current waveform measurement. Rogowski coils have previously been used for special applications of current measurement such as very short duration high current pulses, but have only recently become available as general purpose transducers suitable for power electronic equipment. This requires a bandwidth of 50 Hz to at least 1 MHz for performance comparable to a standard co-axial shunt. Part I examined the Rogowski coil design and behaviour. Part II examines the integrator behaviour at both low (50 Hz) and high (1 MHz) frequencies. It introduces a feedback circuit which overcomes the problems of low frequency noise and drift and it also shows that with appropriate choice of operational amplifier the can be extended beyond 1 MHz. Theoretical noise content is quantified and a transfer function model of the complete transducer is developed. Part III provides results of frequency response tests and recordings of current waveforms with dI/dt up to 3500 A/us for different coil designs and alternative operational amplifiers.
The first part of this paper can be found in EPE Journal Volume 1993-1.