Voltage sag detection based on rectified voltage processing

An algorithm for voltage sag detection based on rectified voltage processing is presented and its performances are evaluated by means of simulated and real voltage waveforms (recorded at some low-voltage busbars and measured on a scaled prototype of a voltage support system). The algorithm is intended to detect voltage sag occurrence and to trigger the disconnection of the faulty supply network and subsequently the connection of a voltage support system. The algorithm is very convenient in terms of memory storage and computational requirements and may be implemented on low-cost platforms. The results show that the time for detection is very short and always less than a quarter of the supply voltage period.