This paper has researched the insulation characteristics of 10% c-C4F8/N2/CO2 mixtures under lightning impulse voltage by experiment. It is shown that the positive and negative lightning impulse breakdown voltages of ...This paper has researched the insulation characteristics of 10% c-C4F8/N2/CO2 mixtures under lightning impulse voltage by experiment. It is shown that the positive and negative lightning impulse breakdown voltages of 10%c-C4F8/N2/CO2 gas mixtures rise linearly as the electrode gap distance and gas pressure increase and under the same conditions, the positive lightning impulse breakdown voltage of the gas mixtures is always higher than the negative lightning impulse breakdown voltage. As the gas mixtures have a little higher liquefied temperature than SF6 and the comprehensive GWP is about 5% of SF6, and the positive and negative lightning impulse breakdown voltages can both reach 60% of SF6, 10%c-C4F8/N2/CO2 gas mixtures can be applied as insulation gas in electrical equipment such as C-GIS, GIT, GIL and so on.展开更多
The increase of voltage level for AC and DC transmission systems requires some changes in the high voltage testing for Ultra High Voltage(UHV) equipment.After a short description of the coordination work in the standa...The increase of voltage level for AC and DC transmission systems requires some changes in the high voltage testing for Ultra High Voltage(UHV) equipment.After a short description of the coordination work in the standardization bodies the requirements for UHV equipment are mentioned.The main points concerning high voltage testing of UHV equipment are the impulse shape of standard lightning impulse voltage,the evaluation of the test voltage for impulses with oscillations or overshoot near the peak and the time parameter of switching impulses.The linearity check of the measuring devices,the proximity effect,the wet tests and the atmospheric correction factors are further points to be discussed concerning testing of UHV equipment.展开更多
基金supported by National Natural Science Foundation of China (No. 51337006)
文摘This paper has researched the insulation characteristics of 10% c-C4F8/N2/CO2 mixtures under lightning impulse voltage by experiment. It is shown that the positive and negative lightning impulse breakdown voltages of 10%c-C4F8/N2/CO2 gas mixtures rise linearly as the electrode gap distance and gas pressure increase and under the same conditions, the positive lightning impulse breakdown voltage of the gas mixtures is always higher than the negative lightning impulse breakdown voltage. As the gas mixtures have a little higher liquefied temperature than SF6 and the comprehensive GWP is about 5% of SF6, and the positive and negative lightning impulse breakdown voltages can both reach 60% of SF6, 10%c-C4F8/N2/CO2 gas mixtures can be applied as insulation gas in electrical equipment such as C-GIS, GIT, GIL and so on.
文摘The increase of voltage level for AC and DC transmission systems requires some changes in the high voltage testing for Ultra High Voltage(UHV) equipment.After a short description of the coordination work in the standardization bodies the requirements for UHV equipment are mentioned.The main points concerning high voltage testing of UHV equipment are the impulse shape of standard lightning impulse voltage,the evaluation of the test voltage for impulses with oscillations or overshoot near the peak and the time parameter of switching impulses.The linearity check of the measuring devices,the proximity effect,the wet tests and the atmospheric correction factors are further points to be discussed concerning testing of UHV equipment.
