A voltage event recorder for more accurate analysis of voltage events in power supply systems

The paper deals with the problems about correct recording and analyzing of voltage events occurred in power supply systems. Based on the results of many of performed simulations which compare the abilities of several known voltage events detection methods to correct analysis of occurred voltage events the paper proposes the usage of Extended Kaiman Filter (EKF) as the preferred method to voltage event detection and monitoring. Except the main advantage of EKF method, which is the possibility of voltage event monitoring in real-time, this method has a lot of other specifics which can be used for better descriptions of detected voltage events. The paper presents a voltage event analyzer based on the EKF algorithm which is able to detect shape of voltage events more precisely than actual used RMS algorithms and on the basis of shape it can determine voltage event parameters more accurately. The analyzer is based on virtual instrumentation in LabVIEW using a data acquisition card from National Instrument.