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.

Physical significance of sub-subtransient quantities in dynamic behaviour of synchronous machines

Abstract: The recent accurate modelling of alternating-current machines sometimes requires, in addition to the known transient and sub-transient quantities, the use of sub-subtransient quantities. The sub-subtransient time constants are very small; they can, however, have a great influence on the machine performance. The physical meaning of these new sub-subtransient quantities for the stability and switch-on process of the synchronous machine is explained and illustrated with examples. It is shown that by introducing the sub-subtransient values, the effect of the solid turborotor and the behaviour of the salient-pole machine with solid poles can be treated with sufficient accuracy.

Exhaust-gas turbine of a turbocharger

Abstract: The object of the invention is to provide a nozzle ring for the exhaust-gas turbine of a turbocharger which, in addition to an improved service life, also guarantees a constant efficiency. According to the invention, this is achieved in that an radial expansion gap (20) is formed between the turbine casing (2) and the nozzle ring (11), and at least one seal (22) is arranged in the expansion gap (20). To this end, an encircling groove (21) accommodating the seal (22) is formed in at least one of the fastening elements (16, 17) of the nozzle ring (11) or in at least one of the components (3, 4, 5) which surround the fastening elements (16, 17).

Koopman Analysis Based Wide-Area Back-Up Protection and Faulted Line Identification for Series-Compensated Power Network

Abstract: The paper presents wide-area back-up protection (WABP) and faulted line identification (FLI) scheme for series-compensated power transmission network. The proposed scheme uses the Koopman mode technique on fault current data obtained from phasor measurement units for WABP and FLI. The main advantage of the proposed scheme is that it is based on spatiotemporal information system (STIS). As we know that in real-world applications, often time and space exist together, and hence, dealing with spatial aspect without considering temporal aspect is of limited use. Similarly, the introduction of series compensation in a power transmission network is common nowadays due to many technical benefits. The FLI in a power network with series-compensation is more complicated due to complex transients produced by series capacitor and the metal–oxide varistor. The proposed scheme is developed using STIS for WABP and FLI under stressed conditions including power swing and load encroachment. The New England 39 bus system is used as the test system, which is developed on Dig-Silent power factory commercial software (PF4C) platform for evaluating the performance of the proposed technique. Further, the efficacy of the proposed scheme is also tested for other critical situations such as symmetrical fault during power swing and multievent detection and found to work effectively.

Rugged fiber-optical current sensor based on the faraday effect

Abstract: A fiber-optical current transformer including a sensor coil, operated in reflection mode, with a sensor fiber (5) for detecting a current utilizing of the Faraday effect. A light source (1) couples light into an incoming first HB fiber (2a). At the end of the first HB fiber (2a), a fiber-optical polarizer (4) is preferably located which ensures a direction of polarization in parallel with a given birefringence axis of the first HB fiber (2a). A Y splitter (3) couples, on the one hand, the supplied light of the first HB fiber (2a) into the sensor fiber (5) and, on the other hand, the light coming from the sensor fiber (5) into an outgoing second HB fiber (2b). The second HB fiber (2b) is rotated with its birefringence axes by 45° with respect to the birefringence axes of the first HB fiber (2a).

Validating a standardized configuration description

Abstract: The present disclosure is concerned with a validation of a configuration description of automated devices in a power network such as a Substation Automation (SA) system, or of a part or component thereof such as an individual Intelligent Electronic Device (IED), that is extended beyond the mere XML schema validation as provided by the known SCL-validation tools. In particular, the disclosure introduces machine-based validation of notations, requirements and/or conventions to be respected by the configuration description and/or the SA system, but not incorporated in or represented by the standardized syntax of the XML schema as defined in part 6 of the IEC 61850 standard. To this end, notations, requirements and/or conventions are initially converted into, or defined as, extended or augmented rules encoded in computer readable format. The content or information of a file having an Substation Configuration description Language (SCL) compliant description of an SA system, or of a part or component there of, is then read by parsing the file and checked for conformance to the rules. Any inconsistency, error, wrong configuration or insufficient description found is displayed to a user, who may then correct the content or information in the file. The procedure according to the disclosure can contribute, in an automated manner, to the correctness of the description of a Substation Automation (SA) system beyond the pure syntactical adherence to the IEC 61850 standard.