An Automatic Data Acquisition Device for Transformer Oscillating Switching Impulse Voltage Tests

The oscillating switching impulse voltage test plays important role in the assessment of transformers. An automatic data acquisition device is developed for this test. Four synchronous A/D conversion channels with 12 bits resolution and up to 10 MHz sampling rate for each channel are assigned to acquire the voltages at the both sides of the tested transformer as well as the currents at the neutral point and on the core earthing line. A smart algorithm to detect the test waveform according to the voltage applied to transformer is developed. It runs in parallel with the sampling program to automatically pickup just the complete test waveform in the sampling data stream. This device greatly facilitates the test operation.