Dielectric Material Characterization
2005-2006
1) Project Title: Accelerated Electrical Degradation of Ship Motor Winding Insulation Energized by Distorted Voltage WaveformsInvestigator: Stanislaw Grzybowski
Objectives: The objective of the proposed project is to gain new insights into the characterization of the electrical properties of the ship motor winding insulation, stressed by distorted voltage, waveform affected largely by 5th harmonics with respect to 60 Hz sinusoid having the same rms. Almost all previous studies outlined only partially the conditions experienced by these motors during the 60 Hz cycles of in-service stresses.
The ship motor winding insulation will be aged at three different voltage magnitudes of square waveform and three different temperatures. At different stages of the insulation degradation (100, 500 and 1000 hrs of applied voltage) the samples will be characterized using different techniques. The evaluation of the dielectric strength degradation of samples will be monitored versus the aging caused by the distorted voltage waveforms. Three measurements will be used: 1) Breakdown Strength Tests of the winding insulation at 60 Hz, 2) Initial Partial Discharge Voltage, Magnitude, Characteristics, 3) Weibull plot relevant to the life time characteristics of the insulation.
The further development of the research project could represent an adequate opportunity for joining together ideas and encouraging scientific contacts between experts from different research fields (e.g. Electrical Measurements and Materials, Reliability, Chemical and Physical Technologies), as a real cooperation between the very different departments involved in producing and exploitation of insulation winding structures is hardly needed. A personal updating, retraining and documentation period is planned at the Electrical and Computer Engineering Department, in the field of High Voltage Measurement Technique, and a useful exchange of information emphasizing the newest achievements in the field of increasing the strength and reliability of winding insulation materials and systems for electrical purposes will be promoted via short courses and seminars too.
2) Project Title: Electrical Degradation of High Voltage Power Ship Cables Energized by Switching ImpulsesInvestigator: Stanislaw Grzybowski
Objectives: The objective of the proposed project is to gain new insights into the characterization of the electrical properties of these high voltage power ship cables, stressed by switching impulses. Almost all previous studies outlined only partially the conditions experienced by these cables during the 60 Hz cycles of in-service stresses.
HV power ship cables will be aged at two different voltage magnitudes of switching impulses and two different temperatures. At different stages of the insulation degradation (100, 500 and 1000 impulses) a sampling of cables will be made and the samples will be characterized using different techniques. The evaluation of the dielectric strength degradation of samples will be monitored versus the aging caused by the impulses applied. Three measurements will be used: 1) Breakdown Strength Tests at 60 Hz, 2) Initial Partial Discharge Voltage, Magnitude, Characteristics, 3) Changes in the Morphology of the Polymer Material due to Aging.
The further development of the research project could represent an adequate opportunity for joining together ideas and encouraging scientific contacts between experts from different research fields (e.g. Electrical Measurements and Materials, Reliability, Chemical and Physical Technologies), as a real cooperation between the very different departments involved in producing and exploitation of cables structures is hardly needed. A personal updating, retraining and documentation period is planned at the Electrical and Computer Engineering Department, in the field of High Voltage Measurement Technique, and a useful exchange of information emphasizing the newest achievements in the field of increasing the strength and reliability of cables materials and systems for electrical purposes will be promoted via short courses and seminars too.
2006-2007
1) Project Title: Accelerated Electrical Degradation of Ship Motor Winding InsulationInvestigator: Stanislaw Grzybowski
Objective: The objective of the proposed project is to gain new insights into the electrical degradation of ship motor winding insulation that is exposed to the electrical and thermal stresses present in ship electrical systems. Impact on the motor winding insulation due to high frequency voltage pulses at high temperature will be studied and compared for different insulation types. Breakdown voltage at 60 Hz will be compared after periods of accelerated electrical degradation. Occurrence of partial discharge will be recorded during the accelerated electrical degradation process. Results from breakdown tests and partial discharge recordings will be compared for lifetime analysis.
2) Project Title: Study of Electrical Degradation of High Voltage Cables Subjected to Switching ImpulsesInvestigator: Stanislaw Grzybowski
Objective: The objective of the proposed project is to gain new insights into the characterization of the electrical properties of the high voltage cable insulation stressed by switching impulses.
