Power quality case histories

As the advantages of information technology and electronic control are increasingly exploited by both manufacturer and consumer, there has been, and will continue to be, an increasing number of power quality concerns for electricity suppliers, equipment manufacturers and customers. This situation has been recognised at East Midlands Electricity plc. (EME), with the formation of a specialist technical team called Power Quality Services (PQS). PQS´ main aim is to deal with the growing concern of EME´s customers on power quality issues, by: investigating and solving customer problems, informing and advising customers on potential power quality problems and how to avoid them, and improving EME´s response to customers by keeping its staff informed and up to date on power quality issues. This paper presents various case histories of investigations that PQS have been involved with covering EM field disturbances causing VDU image jitter, flicker disturbance, a disturbing load, and sensitive load equipment