Power quality in the NGC grid system

Power quality can be an issue between the customers connected to a supply system, both those who affect the voltage waveform quality in some way and those who are affected by a distortion of the voltage waveform, and the system operator. Generally this will be between those customers who wish to contribute significantly to the distortion or disturbance levels on the system and the system operator. Guidance on the acceptable levels of disturbance from a customer has for a long time in the UK been formalised in a series of Engineering Recommendations prepared by the Electricity Council and now administered by the Electricity Association. The author briefly outlines the most relevant recommendations and then discusses unbalanced voltage and power system harmonics seen at 132 kV and above