Support for standardisation of high voltage testing with composite and combined wave shapes

High voltage AC or DC networks are being introduced which transmit electricity more efficiently. Lightning strikes or the sudden removal of high power-drawing devices cause ‘lightning impulses’ (LI) and ‘switching impulses’ (SI). These power surges become superimposed over the electricity flowing through the grid altering its ‘waveform’ causing damage to lines and substations. International standards specify tests required for determining component resilience to voltage impulses but presently lack traceability for all effects caused by overlapping waveforms, leading to incorrect test results.  Guidance for setting up or calibrating the systems used for simultaneous LI and SI measurements is also lacking.

The project investigated the interaction of impulse voltages superimposed with AC and DC voltages enabling optimised test setups to be created. The uncertainty of existing measuring systems will be determined, and new systems and calibration capabilities will be created and validated through measurement campaigns. At the end of the project in 2023 the results will input into revision of existing standards, generate new European capabilities and improve the robustness of power grids to adverse operational events.