As one of the most important parts of the generator, Epoxy/mica insulation system has the direct effect on the reliability of generator operation. The accelerated aging of insulation system was taking place under the complex operation condition, and resulting in the insulation system breakdown. It had always been the target for the researchers to find an efficient way to evaluate the state of generator insulation system. According to the real operation situation, the multi-factor aging test sequence with electric field, temperature field, mechanical vibration and thermal cycling was developed, and the test platform with multi-factor aging was built in this research. The partial discharge test was conducted at the end of each cycle. The result showed that, with the insulation aging time prolonged, the maximum partial discharge quantity decreased first then increased while skewness and kurtosis varied the opposite way. And the phase range of partial discharge began to expand. This research provided a new way to evaluate the state of generator insulation system.
In this research, the anti-corona lacquer with different SiC content was fabricated. The surface resistivity of the lacquer at different voltage levels was measured, and the effect of the SiC content on electrical properties of SiC anti-corona coating was investigated. The results showed that the initial surface resistivity ρs decreased with increasing mass ratio of SiC to resin, while the non-linear coefficient β varied the opposite way. The surface resistivity was improved by adding suitable amount of graphite, which suited the requirements of multiple sections anti-corona structure.
As the pumped storage stations played an important role in peak and frequency modulation, the reversible pump turbines were often subjected to rapid temperature transitions. In this research, considering the complexity operation condition of these kinds of motors, a novel thermal cycle aging platform was designed and the thermal cycling aging test was conducted on epoxy/mica insulation stator bars. Dielectric loss angle tangent (tanδ), capacitor (C), leakage current (I) and other electrical properties of stator bars were investigated at different aging time. The results showed that, tanδ and C of the stator bars increased with increasing aging time, while I (current) did not change significantly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.