The partial discharge measurement is a typical non-destructive test and it can be used to judge the insulation performance at the beginning of its service time taking into account the reduction of the performance during the service time by the ageing whereby the ageing depends on numerous parameters like electrical stress, thermal stress and mechanical stress. Depending on the kind of insulating material different limits for the allowed partial discharge value at a given stress are defined in the relevant recommendations. In particular for solid insulation where a complete breakdown damages seriously the test object the partial discharge measurement is a tool for the quality assessment.

Chapter Contents:

• 17.1 Introduction
• 17.2 Physical background of partial discharges
• 17.3 Requirements on a partial discharge measuring system
• 17.4 Measuring systems for apparent charge
• 17.5 Calibration of a partial discharge measuring system
• 17.6 Examples of partial discharge measurements
• 17.6.1 Partial discharge measurement on high-voltage transformers
• 17.6.2 Partial discharge measurement and location on high-voltage cables
• 17.6.3 Partial discharge measurement on high-voltage gas-insulated substations
• 17.6.4 Development of recommendation
• 17.7 Summary
• References

Inspec keywords: insulating materials; partial discharge measurement; nondestructive testing

Other keywords: insulating material; service time; mechanical stress; ageing; thermal stress; partial discharge measurement; insulation performance; electrical stress; nondestructive test

Subjects: Charge measurement; Insulation and insulating coatings; Materials testing