ABB Ltd

About: ABB Ltd is a company organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Voltage & Signal. The organization has 6222 authors who have published 6852 publications receiving 83994 citations.

Explosion tests on IGBT high voltage modules

Abstract: In this paper, we report on surge current experiments with IGBT modules in low inductance, snubberless circuits. We give design guidelines for robust modules and robust converter designs, discuss scenarios of consequential damage and propose worst case test conditions for explosion safety. For wire bonded modules, the limit for material ejection is at a stored capacitive energy of about 10 kJ. In a good design, the shock wave trajectory is defined and no metallic parts obstruct the plasma expansion. The worst case damage occurs if, initially, a single chip fails. Press-pack modules can be designed to contain the plasma inside the housing in the case of a short circuit. Simple protective measures are sufficient to protect personnel.

Optical-fibre sensor

Abstract: Ein faseroptischer Sensor zum Messen einer bestimmen Richtungskomponente eines elektrischen Feldes umfasst einen piezoelektrischen Korper (4) und eine Glasfaser (5a), welche in einem gegebenen Langenabschnitt mit dem piezoelektrischen Korper (4) starr verbunden ist. A fiber optic sensor for measuring a component determining the direction of an electric field comprises a piezoelectric body (4) and a glass fiber (5a) which is rigidly connected in a given length section of the piezoelectric body (4). Eine Kristallklasse und eine kristallographische Orientierung des piezoelektrischen Korpers (4) ist so gewahlt, dass nur diejenige Richtungskomponente des elektrischen Feldes mittels eines inversen piezoelektrischen Effektes eine Aenderung einer Lange der Glasfaser (5a) bewirkt, welche parallel zu einer gegebenen Korperachse (h) des piezoelektrischen Korpers (4) liegt. A crystal class and a crystallographic orientation of the piezoelectric body (4) so ​​that only the one directional component of the electric field by means of an inverse piezoelectric effect causes a change in length of the glass fiber (5a) which is parallel to a given axis of the body (h) of the piezoelectric selected body (4). Die Aenderung der Lange wird interferometrisch gemessen. The change in length is measured interferometrically. In einer bevorzugten Ausfuhrungsform hat der piezoelektrische Korper die Form einer Scheibe, einer Platte oder eines Hohlzylinders. In a preferred embodiment, the piezoelectric body has the shape of a disc, a plate or a hollow cylinder.

Sensor head for a fiber-optic current measuring device

Abstract: The sensor head (1) is intended for a fiberoptic current measuring device. It exhibits a twisted low-birefringence LB fiber (14) which is guided around a current conductor (2) and serves to conduct polarized light. Using the LB fiber (14), the Faraday rotation of the polarized light, which rotation is generated by the magnetic field (H) of the current (J) to be measured, is detected. The LB fiber (14) is spliced at its two ends in each instance with one of two polarization-conserving, light-conducting HB fibers (6, 7), one (6) of which supplies the polarized light. The two HB fibers (6, 7) are secured in each instance in the vicinity of the two splice locations (19, 20) with the absorption of the torsional force generated by the twisting of the LB fiber (14). In spite of having a simple and sturdy structure, the sensor head (1) is distinguished by a high degree of measurement accuracy.

Method and device for the autolubrication of the rolling bearings of turbomachines

Abstract: A method and device for the autolubrication of the rolling bearings of turbomachines. The method and device utilize pressure differences present in the turbomachine for sucking in the lubricating oil. Moreover, a pressure is built up in centrifuges arranged on a shaft, and is used for the direct injection of the lubricating oil into the rolling bearings. For this purpose, an annular element imparting a negative pressure is arranged stationarily on the shaft, and is designed as a negative pressure chamber. The negative pressure chamber is connected via an oil suction conduit to an oil sump holding the lubricating oil and via a first air conduit to a negative pressure region of the turbomachine. The oil sump is connected via a second air conduit to an overpressure region of the turbomachine. A separating point is arranged between the oil suction conduit and the negative pressure region, preferably in the first air conduit.

Combined Characterization of Free-Moving Particles in HVDC-GIS Using UHF PD, High-Speed Imaging, and Pulse-Sequence Analysis

Abstract: Reliable operation of high-voltage equipment depends on defect-free HV insulation systems. However, defects in the insulation can lead to partial discharge (PD) activity. PD measurement has been shown to be a useful tool for evaluating the condition of high voltage components including gas-insulated switchgear (GIS). This work focuses on characterizing the motion and PD signal behavior of free-moving particles in an experimental GIS arrangement under high dc field stress. For this purpose, the particle geometry, material composition, and amplitude of the applied negative dc voltage are varied. PD signals are measured using a broadband ultra-high-frequency (UHF) sensor and recorded in the time domain. The UHF signal is used to trigger a synchronized high-speed camera in order to observe the correlation between particle motion and UHF PD pulse activity. Certain unique combinations of UHF pulse repetition rates and signal amplitudes in the time domain are observed that depended on and were correlated with particles’ motion. These are evaluated by means of pulse sequence analysis, whose significant clusters enable estimation of particle motion. In particular, particle motion with small hopping amplitudes on the negative electrode—known as “firefly”—is differentiated with high accuracy.