The aim of this work package is to provide a substantial contribution to the revision of IEC 60060‑1&2 and IEC 61083‑1&2, which are now in preparation in TC 42. This work package will focus on the low voltage instruments (digital recorders) and software that are used for the evaluation of HV composite and combined tests. Methods will be developed, based on requirements, for use with the software and instruments. In addition, new algorithms and new techniques will be developed for the qualification of digital recorders. The aim is also to understand what happens during composite and combined tests. This will be undertaken by researching the existing literature in a range of diverse areas of application, and by setting up suitable measuring instruments and the test procedures for their evaluation. Additionally, the software used with the measuring devices, including reference waveforms and the values required to meet the uncertainty of the measurements, will be developed. This work package will provide input to support the work being performed in IEC TC 42.

Composite and combined wave shapes are generated using two separate generating circuits, e.g. one for d.c. voltage generation and another one for lightning impulse voltage generation. The superposition of these voltage forms is carried out either by a spark gap or a coupling capacitor. The scientific findings in this project on the interaction of the impulse voltages superimposed with d.c. or a.c. voltage will enable optimised test setups to be created for superimposed voltages.

This work package will lead to:

  • A list of definitions of the quantities to be measured for composite and combined wave shapes and they will be reported to TC 42.
  • Methods, which can be used to evaluate low voltage measuring instruments and requirements will be developed for their use. These will be published and reported to TC 42.
  • New software being developed for the measuring devices that are used for the evaluation of the parameters of composite and combined wave shapes. Furthermore, it will support the future revision of the IEC 61083 series standards on test data generators.

The aim of this work package is to develop traceable measurement systems and calibration services for composite and combined wave shapes, with a target amplitude uncertainty of less than 2 %. Therefore, a modular universal voltage divider (a traceable reference system) will be designed and built for use in the calibration of the measurement systems that have been designed for measuring composite and combined waveforms. The low voltage instruments and the software designed in WP1 will be used as a part of the reference system. A measurement campaign will be arranged to verify the performance of commercial systems and the modular universal voltage divider (traceable reference system).

This work package will lead to

  • The development of a modular universal voltage divider for use in the calibration of the measurement systems that have been designed for measuring composite and combined waveforms.
  • The accuracy limits, of the reference measuring systems that are used for measuring composite and combined waveforms, being determined. Furthermore, commercial reference measuring systems and the new modular universal voltage divider (a traceable reference system) will be characterised using the new test setup. At least 3 modular universal voltage dividers will be validated for use in reference systems.

The aim of this work package is to test the reference voltage dividers and measurement systems from WP2 that are used in HV testing with composite and combined wave shapes. A measurement campaign will be arranged to verify the performance of the existing commercial universal voltage dividers that are available at the test laboratories (TUG, TUD, Haefely). The ability of the existing commercial universal voltage dividers to measure composite and combined voltages will be investigated. Tests will be performed at voltages > 750 kV to check the influence of the dimensions of the commercial universal voltage dividers on the performance and accuracy of the measurement system. Only then will it be possible to make a reasonable statement as to whether the previous calibration method is practical or whether it will need to be completely revised. At the end of the project, the result will be forwarded to TC 42 to be considered for inclusion in the new IEC 60060. As a result, the test institutes will be able to carry out comparable high voltage tests on equipment from then on and they will thus influence the reliability of the transmission and distribution grids.

This work package will lead to two measurement campaigns at TU Graz and TU Dresden. It will result in evidence of the metrological capability of existing measuring systems for high voltage composite and combined testing. Furthermore, this wok package will lead to a final statement on the performance (accuracy limits: with a target amplitude uncertainty of less than 2 %) of the reference measurement systems and the high voltage composite and combined wave shape capabilities of the testing institutes.