Breaker Capacitor Dielectric Loss Characteristics Of Study

As the power grid is growing larger and voltage level is increasing, the circuit-breaker rated voltage level is increasing. Circuit-breaker capacitor is applied widely in power system in order to enhance the voltage distribution in the break fracture, and to improve the withstand voltage level to insure the security work of the power system. It is necessary to do a preventive test. In the test, dielectric loss angle measurement is a crucial part.A phenomenon is discovered from the test of operative capacitors by The LuoYang power corporation: The tg8 of film-paper composite insulation circuit-breaker capacitors exceeds the standard at lower voltage and qualifies the standard at higher voltage. This paper verifies this phenomenon which is ubiquitous in test by 2801 bridge and AI-6000C digital bridge. Based on the experiments and experiences, the paper gives a experiential formula to calculate the range of tg δ. According to the dielectric theory, the paper builds the model of the capacitor's dielectric loss to compute the approximate tg δ. Gases chromatography is also applied to the analysis of circuit-breaker capacitors. It interprets the phenomenon in theory and provides evidence for the determine of capacitors performance. It suggests to loosen the prevention test standard. At last this paper gives some technical advice to the manufacture of capacitors.