Effects of combined stressing on the electrical properties of film and ceramic capacitors
Advanced power systems which generate, control and distribute electrical power to many large loads are a requirement for future space exploration missions. The development of high temperature insulating materials and power components constitute a key element in systems which are lightweight, efficient, and are capable of surviving the hostile space environment. In previous work, experiments were carried out to evaluate film and ceramic capacitors for potential use in high temperature applications. The effects of thermal stressing, in air and without electrical bias, on the electrical properties of the capacitors as a function of thermal aging up to 12 weeks were determined. In this work, the combined effects of thermal aging and electrical stresses on the properties of teflon film and ceramic power capacitors were examined. The ceramic capacitors were thermally aged for 35 weeks and the teflon capacitors for 15 weeks at 200/spl deg/C under full electrical bias and were characterized, on a weekly basis, in terms of their capacitance stability and electrical loss in the frequency range of 50 Hz to 100 kHz. DC leakage current measurements were also obtained. The results obtained represent the influence that short-term thermal aging and electrical bias, have on the electrical properties of the power capacitors characterized.<<ETX>>
New topology and predictive control for photovoltaic application with inductive power decoupling capability
An important trend is the use of plug and play microinverters attached to the PV panel, allowing the so called AC module. However, these converters are subjected to high temperature and humidity. Thus, in order to improve reliability and achieve long lifetime, this work proposes a new topology that provides inductive power decoupling and eliminates electrolytic and even film capacitors, using a single ceramic or mica capacitor. The topology also provides inductor miniaturization and efficiency improvements.
Electrical Characterization Of Glass, Teflon, And Tantalum Capacitors At High Temperatures
Dielectric materials and electrical components and devices employed in radiation fields and space environment are often exposed to elevated temperatures among other things. These systems must, therefore, withstand the high temperature exposure while still providing good electrical and other functional properties. In this work, experiments were carried out to evaluate glass, teflon, and tantalum capacitors for potential use in high temperature applications. The capacitors were characterized in terms of their capacitance and dielectric loss as a function of temperature up to 200/spl deg/C. At a given temperature, these properties were obtained in a frequency range of 50 Hz to 100 kHz. DC leakage current measurements were also performed in a temperature range from 20 to 200 /spl deg/C. The results obtained are discussed and conclusions are made concerning the suitability of the capacitors investigated for high temperature applications.