The application of the virtual instrument technology in high voltage measuring system

The traditional way of high voltage (HV) measuring has some intrinsic shortcomings. With the recent improvement in digital measuring techniques and computers, digital automated measuring are become more prevalent. The virtual instrument (VI), which is a new technology in signal detecting, analyzing and processing, has been the authors´ main focus. This paper introduces the concept and characters of VI, its three main types and presents a PC-based VI to measure 8/20 μs impulse current. The VI is implemented in the two ways: the popular object-oriented programming language-Visual C++, and the famous graphical programming environment-LabVIEW. Signals are processed with the digital filter, smoothing window and fast Fourier transformation (FFT). Wave parameters can be calculated quickly and shown in the soft front panel. It can also be used to measure other high voltage waves after changed a little.