Short circuit calculation

A basic task of power systems engineering
„Installations shall be designed, constructed and erected to safely withstand the mechanical and thermal effects resulting from short-circuit currents[.…] Installations shall be protected with automatic devices to disconnect three-phase and phase-to-phase short-circuits.“
- Extract from the standard IEC 61936-1: Power installations exceeding 1 kV a.c.

Task
For the dimensioning of the electrical system, it is essential to know the magnitude of short-circuit currents. While the maximum short-circuit currents essentially define the design of the equipment such as switchgear, switches, transformers, etc., the minimum short-circuit currents form the basis for the design and setting of the protective devices. Furthermore, short-circuit calculations form the basis for the design of earthing systems, personal protection and stability calculations.

Current status of standardization
An important part of the short-circuit calculation is the international standard IEC 60909: Short-circuit currents in three-phase a.c. systems and its German version, the standard DIN EN 60909: Short-circuits in three-phase systems. As chairman of the Austrian committee and as a member of the corresponding international committees, Prof. Schürhuber works on the implementation and further development of this standard, which is of practical importance for electrical power engineering, and also deals with various special issues.

This includes, for example, the investigation of the short-circuit behaviour of power electronic components and their modelling for the standard, as well as the short-circuit behaviour of grids with load flow fluctuating due to the integration of renewable generation, and the influences of the cause of real grid faults and their effects.

Calculations at the Institute of Electrical Power Systems
The performed calculations cover the entire spectrum of short-circuit calculation and range from the method in symmetrical components, IEC standard calculations to transient simulations. This includes classical models and equivalent circuit diagrams as well as detailed component considerations (e.g. switching arc models) and short-circuit considerations of various inverter topologies. In addition to simulation and computation, many power system structures can be verified in the laboratory using an analog network model as well as a power hardware-in-the-loop.

Besides the calculation of short-circuit currents, the Institute of Electrical Power Systems also accompanied short-circuit tests in Hessenberg and Rosenau and provided the necessary scientific preparation.

Publications / Reports
2020
Schachinger, P., Schürhuber, R.
Einfluss von Lichtbogenmodellen auf Kurzschlussgleichstromglieder
Projektbericht

2019
Rainer, A., Renner, H., Schürhuber, R.
Analyse der SASA-Netzstörung vom 28.08.2016
Projektbericht

Herbst, D., Schürhuber, R., Schmautzer, E., Fürnschuß, M., Auer, Ch.
Überprüfung der Schutzmaßnahmen zum Schutz gegen elektrischen Schlag von DC-Ladestationen für Elektrofahrzeuge
In: 11. Internationale Energiewirtschaftstagung - IEWT 2019, Freiheit, Gleichheit, Demokratie: Segen oder Chaos für die Energiemärkte?, 13.02.2019 [Paper und Vortrag]

Schürhuber, R.
Short circuit behaviour of AFE converters
In: Internal Report for DKE 121

2018
Hufnagl, E., & Schürhuber, R.
Kurzschlussversuche in den Umspannwerken Hessenberg und Rosenau
Präsentation, 2018

Hufnagl, E., Polster, S. C., Schürhuber, R., Fickert, L., Achleitner, G., Skrbinjek, O. & Braunstein, R.,
Auswirkung der einpoligen AWE auf unterlagerte Verteilnetze
In: Schutz- und Leittechnik 2018, 10. FNN-/ETG-Tutorial VDE.[Paper und Poster]

 2016
Schürhuber, R.
Die Kurzschlussnorm IEC 60909-0: 2016 – Neues und Änderungen
In: e&i - Elektrotechnik und Informationstechnik,2016 Datum, Journal Paper