Analysis of dielectric response measurement methods and dielectric properties of resin-rich insulation during processing

摘要: The dielectric diagnostic methods ofpolarisation/depolarisation currents and recovery voltage,which are time domain methods, capacitance tandmeasurements at different frequencies, which is a frequencydomain method, have been studied here. In the first part of thethesis, these measurement analysed evaluated.Three types insulation systems included in theevaluation, oil/paper ("high" loss), resin-rich mica tape("medium" loss) cross-linked polyethylene, XLPE, ("low"loss). These three responsein both shape magnitude. Conclusions made regardingchoice method depending on dielectricresponse material. Examples also given ofhow to estimate conductivity responsefunction from measurements with finitecharging period.Furthermore, relations between possibilities Fourier transforming data fromone other discussed. isdone spline approximation technique, Hamonapproximation by fitting base functions that analyticFourier transforms measured data. techniques arereviewed special attention problem estimatingdata outside window.The second thesis includes studies changeof properties during manufacturing stage acomposite used high voltage rotating machines.The consists tape wovenglass or polyester film (PET) as carrier aim wasto improve quality composite byoptimising heat pressure cycle theproduction.A test cell has designed built be able toprocess simple parallel plate samples under conditions similarto factory process. With maximum heating rate 9°C/min cooling 20° C/min arbitrarytemperature paths could programmed. All wereprocessed static MPa range.The chemical reaction curing micatape was differential scanning calorimetry (DSC).A model fit DSC measurementsmaking it possible calculate degree anarbitrary temperature path.The change response curingunder constant pressurewas monitored. Both laboratory experiments factorymeasurements based asimple network proposed explain measureddielectric terms material structure degreeof curing.Keywords: Dielectric response, Hamon,Fourier transform, rotating-machine, insulation, resin-rich,mica tape, curing, process, monitoring, scanningcalorimetry (DSC), model.