On-line over-voltage monitoring system based on virtual instrument

According to characters of internal and external over-voltage in transmission network, an on-line over-voltage monitoring system based on virtual instrument is designed, which takes the resistance-capacitance voltage divider as the signal acquiring equipment. The signal conditioning unit processes the signal from voltage divider. The trig-in-advance technology is used to effectively start signal acquisition when over-voltage comes. The system software is based on virtual instrumentation technology. Cooperated with high-speed digitizer, it calls and analyzes data, and displays them in graphics. Data compression technology and network technology are applied for remote accessing to field over-voltage. The simulative test in high-voltage lab and the site operation show that, the system is stable and accurate, and the tested data and recorded waveform reflect the power line over-voltage truely.