Power system disturbance patterns

Power system disturbances (e.g. surges) may or may not affect the performance of sensitive electronic and electrical equipment. When the performance of a utility´s customer´s sensitive equipment is significantly affected by alleged power supply disturbances, then the utilities may become involved in a complex process of detecting the possible patterns of the occurrences of these disturbances which may identify the origins of the power supply anomalies affecting the customer´s electronic equipment. The activities, involving the utility and its customers, directed at mitigating the impact of power system disturbances on sensitive electronic equipment are discussed. The importance is stressed of having an adequate knowledge of the utility and its customer´s electrical power system configurations and their operational activities prior to initiating a monitoring scheme to detect power supply anomalies. The disturbance patterns in a power supply system monitored continuously at a single site over a two-year period are presented, and the problems that might evolve from short-term site monitoring are discussed