IEC EN 60909-0 Short Circuit Currents in Three-Phase Alternating Current Systems - Part 0: Calculation of Currents

EUROLAB, with its state-of-the-art accredited laboratories and expert team, provides precise and fast testing services within the scope of IEC EN 60909-0 test. IEC EN 60909-0 applies to the calculation of short-circuit currents in low-voltage three-phase AC systems operating at a nominal frequency of 50 Hz or 60 Hz, and in high-voltage three-phase AC systems. It establishes a general, practical and concise procedure that leads to generally acceptable results and deals with the calculation of short-circuit currents in the case of balanced or unstable short-circuits.

This edition includes the following important technical changes from the previous edition:

• Contribution of wind power station units to short circuit current;
• Contribution to short-circuit current of power station units with full-size converters;
• New document structure.

This part of IEC EN 60909 establishes a general, applicable and concise procedure that often leads to results of acceptable accuracy. For this calculation method, an equivalent voltage source is introduced in the short-circuit position. This does not exclude the use of special methods, such as the superposition method, which adjusts to certain conditions, if they give at least the same precision. The superposition method gives the short-circuit current for an assumed load flow. Therefore, this method does not necessarily result in the maximum short-circuit current.

Short-circuit currents and short-circuit impedances can also be determined by system tests, measurement on a network analyzer or a digital computer. In existing low-voltage systems it is possible to determine the short-circuit impedance based on measurements where the possible short-circuit is concerned.

The calculation of the short-circuit impedance is generally based on the rated data of the electrical equipment and the topological arrangement of the system and has the advantage of being possible for both existing systems and systems in the planning stage.

EUROLAB assists manufacturers with IEC EN 60909-0 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.