International Electrotechnical Commission

Guide for a Test Procedure for the Measurement of Loss Tangent of Coils and Bars for Machine Windings - Edition 1.0; Includes Corrigendum: 07/1987
 N TR 60894

Annotation

The characteristics of an insulation system can be evaluated in terms of dielectric strength, insulation resistance, dielectric loss, etc.

This report is applicable to a method of measuring dielectric loss properties of the insulation system of the slot portions of new coils or bars for rotating electrical machines having rated voltage UN of 5 kV and above.

The test is applicable to form wound coils or bars in which the insulation is cured before the winding is inserted in the stator.

For tests on post-impregnated machines, see Appendix A.

Object

The uniformity of manufacture is judged to some extent by measurement of the dielectric loss tangent as a function of voltage and by statistical evaluation of the test results.

For a known insulation system, the following properties can be assessed:

- a low loss tangent at low voltage (0.2 UN) indicates a high degree of molecular crosslinking of the bonding medium (degree of resin cure),

- the magnitude of delta tan delta by increase of voltage gives some indication of the void content  of the insulation.

Автоматический перевод:

Гид для процедуры проверки для измерения касательной потерь катушек и брусков для машинных обмоток - издание 1.0; включает исправление: 07/1987