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EPE Journal Volume 11-1 - Papers
- The Current Sensors in Power Electronics, a Review
- Design of Processing System for State Diagnosis of Electrolytic Capacitors
- Special Test Circuits for the Analysis of IGBT Behavior in ZCS Commutation
- High-Frequency High-Voltage DC Isolation Transformer-Rectifying Module for Power Supply of Technological Equipment
EPE Journal Volume 11-1 - Editorial
By B. Sneyers
The Editorial of the EPE Journal Volume 11 N°1, "E=TeM˛ and EPE 2001. Do not miss our next events.", written by Ir. Brigitte Sneyers, the Secretary General of EPE Association.
EPE Journal Volume 11-1 - Papers
By F. Costa; P. Poulichet; F. Mazaleyrat; E. Labouré
Current sensors are widely used in all the fields of electrical engineering and power conversion. The applications are very diverse: current measurements in semiconductors, current sensing for variable speed drive, current measurement in high voltage networks. These examples show the great diversity of performances, electrical constraints and environmental constraints of these sensors. In this paper ,a state-of-the-art is presented about the main types of sensors, so that the user can optimise his choice with respect to the problem to solve.
By A. Lahyani; P. Venet
In this paper, a system for predictive maintenance of electrolytic capacitors in static converters is presented. The failure of these capacitors leads to an increase of their equivalent series resistance ESR and therefore the voltage ripple across the components rises. This waveform must be filtered to extract its fundamental component to get a good image of ESR. For power supply with variable switching frequency, electronic filter with controlled center frequency is realised. This center frequency is adjusted by the V.C.O. of converter's control circuit. The voltage ripple also depends on the converter parameters such as input voltage, output current and ambient temperature. A reference system taking into account all these parameters is determined for sound capacitors. A good interpretation of the increase of the ripple voltage allows then, the determination of ESR value. The remaining time to the failure of the capacitors is then deduced.
By A. Claudio; J. Aguayo; M. Cotorogea
Higher switching frequencies are required to reduce the weight and size of passive energy storing components in power electronics systems. Switching loss reduction through soft commutation techniques such as zero-current-(ZCS) and zero-voltage switching (ZVS) is widely applied in converter designs. Test circuits are commenly used for the characterization of the switching behavior of semiconductor power devices in order to better evaluate their switching losses. This work presents the operation and design considerations of two special test circuits used for the characterization of IGBTs in ZCS commutation. The study considers the variation of important test parameters such as the hold-off time. IGBT turn-off instant, switched current, supply voltage and junction temperature.
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By N. Komarov; A. Podoltsev; I. Kucheryavaya; B. Lebedev
Highly efficient (98%) transformer-rectifying module (20 kW, 20 kHz, 5kV d.c. isolation) for high-voltage power supplies is examined. The design of transformer in a structure of the module is based on settlement of a number of technical contradictions. Minimum leakage inductance is to be provided at large space gap between windings. Electrostatic shields give a possibility to reduce the effects of system transients. At the same time, they raise equivalent capacitance of transformer and cause stepping-up of voltage at no-load. this paper represents results of investigation of electromagnetic and thermal processes in the module and proposes some ways for solving the contradictions indicated.