A test setup with automated measurements for impulse voltage breakdown studies of gaseous insulation

To estimate the complete probability distribution function of breakdown voltages and time of gaseous insulation under impulse voltages, a large number of voltages have to be applied in constant voltage tests. In order to perform these experiments with minimum of manual intervention, a personal computer (PC) based automated set up is developed. The PC is used to trigger the impulse voltage generator at the required regular intervals and also to acquire the impulse voltage waveform data from the digital storage oscilloscope (DSO). This waveform data is analysed by programs to get the required information such as whether a breakdown has occurred or not (chopped impulse or not) and if it is a breakdown, the time and voltage at the instant of breakdown. This information from a series of tests is stored in a file and can be fed to other programs for detailed statistical analysis. The test set up and the algorithms of the programs for measurements from the digitized data of impulse voltage waveform are described