An easy VI program to detect transient disturbances in the supply voltage

The assessment of the "power quality" and "voltage quality" in a deregulated electricity market has become a more and more critical point. As far as the voltage quality is concerned, the first step towards its assessment is the availability of measurement systems able to detect and classify all possible disturbances affecting the voltage itself. This task is quite difficult when transient disturbances are involved, and very complex algorithms have been proposed, mainly to classify these disturbances. This paper proposes a very simple detection algorithm, whose aim is to act as a real-lime "trigger" for subsequent, more complex classification algorithms. A VI has been realized implementing this detection algorithm in real-time and the experimental results collected during several months of operation are reported.