Introduction: The use of Partial Discharge (PD) measurement is a well known method of checking the condition of electrical insulation. Over the past 10 years, UKPN have been actively involved in the development of online partial discharge monitoring and mapping techniques. Opportunities to improve the existing technology have been identified.

This project has developed equipment to continuously monitor PD activity in underground cables and switchgear.

Objectives: The issues being investigated by the project are:

• Online fault detection and location

• Pre-emptive fault repairs

• Cable replacement and maintenance strategy

• Quality of supply improvement.