Computer aided partial discharge testing of thin solid insulation systems

For the assessment of thin insulation films in electrical equipment and components a computer aided partial discharge (PD) measuring system is presented. Those insulations are e. g. used in optocouplers, transformers, capacitors and all kind of coating, for instance on printed circuit boards (PCB). The test specimen are taken out of industrial production and are typical for the present manufacturing standard. Two types of test results are presented: Type I shows the PD‐behaviour for long time stress with the test voltage kept constant at a value not higher than ].5 times the PD‐inception voltage (Uj). Type 2 shows the PD‐behaviour for short time stress when the test voltage is increased continuously up to the breakdown voltage of the test specimen. The results are discussed for coated printed circuit boards.