Performance comparison of voltage sag source detection methods for power quality diagnosis

Voltage sag is considered as a major power quality problem that can disrupt the operation of sensitive equipment. Many power utilities around the world install power quality recorders at strategic sites to monitor the frequency and severity of voltage sags that may affect their customers. The identification of sources of voltage sags is also critical for determining the causes of the disturbances. The source of sag can either originate from upstream or downstream with respect to the monitoring point. This paper presents a comparative study to investigate the performance of the various voltage sag source detection methods, namely, the Voltage-Current, Disturbance Power, Incremental Impedance, Directional Relay, Real Current Component and Stransform Disturbance Power methods. The results showed that the STDP method is superior in detecting symmetrical and asymmetrical voltage sag sources in industrial power systems compared to the other compared methods.