Challenges for high voltage testing of UHV equipment

The increase of voltage level for AC and DC transmission systems requires some changes in the high voltage testing for Ultra High Voltage (UHV) equipment. After a short description of the coordination work in the standardization bodies the requirements for UHV equipment are mentioned. The main points concerning high voltage testing of UHV equipment are the impulse shape of standard lightning impulse voltage, the evaluation of the test voltage for impulses with oscillations or overshoot near the peak and the time parameter of switching impulses. The linearity check of the measuring devices, the proximity effect and the wet tests are further points to be discussed concerning testing of UHV equipment.