Substation test system adds multiple timing test
To increase the range of sub-station and relay protection system tests that can be performed, Megger has added a multiple timing test (MTT) feature to its multi-function SVERKER 900 test set. This new feature provides an aid for checking the performance of over-current devices with an inverse definite minimum time (IDMT) tripping characteristic.
The SVERKER 900‘s functions cover all of the major requirements for single- and three-phase testing in distribution sub-stations. It can be used by distribution network operators and also for testing protection systems in renewable power generation installations and in industrial applications.
The SVERKER 900 has an intuitive user interface that is accessed via a large colour touchscreen. The user can select from pre-configured virtual test instruments to select the required test function. An internal processor means that, for most types of manual and semi-automatic testing, an external computer is not needed.
The MTT test function allows users to inject multiple currents with different amplitudes and monitor the tripping time for each current. The maximum time for which each of the currents is applied can be set, allowing the IDMT tripping characteristics to be confirmed quickly and easily the need to perform multiple tests. For ease of inspection and interpretation, results are displayed in both graphical and tabular formats.
Other test sets available for the SVERKER 900; three current and four voltage generators can be provided and there is an extra voltage generator for testing distance protection with synchro-check function.
Amplitude, phase angle and frequency of all current and voltage generators can be adjusted individually and current and voltage generators can be connected in parallel or series to provide single-phase outputs of up to 105A and 900V for current transformer testing.
Megger advises that the SVERKER 900 is suited to commissioning and maintenance of distribution sub-stations and generator installations, testing electromechanical, static and numerical protection relays, plotting current transformer excitation curves, polarity/direction measurement, impedance measurement, single- and three-phase injection testing in switchgear, checking SCADA annunciation and measurement values and performing network measurements.