| There are important theoretical significance and engineering practice value to do the research about the effect of ultraviolet radiation (UV) on the discharge of non-uniform electrical field. According to literatures, UV intensity on the ground increases with sea level elevation; the basic requirements of UV to analogue that of ground are, spectrum within 280 nm~400 nm should be continuous and correspondence with that of the solar as possible as it can be, the sum intensity of UVA and UVB should be no lower than 110 W·m-2, the ratio of them is about 11:1. Based on that, the test in this paper was designed for the effect of UV on the air discharge of rod-plane, using high air pressure sphere xenon lamp (Xe) and high air pressure sphere hydrargyrum-xenon lamp (Hg-Xe) separately. The following are the main results:1. The analogue of UV radiation result's comparison of two kinds of UV source shows the Xe lamp is better for the test.2. AC and DC(+) voltage discharge test were put up for the air gap of which the electric poles are made of Fe and Al, and the each length is 5 cm,10 cm,15 cm, under the air pressure of 98 kPa and 58 kPa using the two kinds of UV sources. The result shows there is neither consistent increase nor decrease regular pattern of the AC and DC breakdown voltage with the increasing of UV intensity, even after adjustment of temperature and humidity of the air gap on breakdown voltage.3. For the 10 cm rod-plane air gap of which the electric pole are made of Fe and Al, the test research of getting U50 in ordinary air pressure was developed under negative polarity operational impulse voltage, using the two UV sources. The result shows: U50 of the Fe-made air gap tends to continuous falling with the increase of Xe lamp's UV intensity, but as for Fe under UV radiation of Hg-Xe, and for Al under UV radiation of the two UV sources, there is no such phenomenon.4. Tests were made to get the Volt-Second Characteristics of Fe-made rode-plane air gap under negative polarity operational impulse voltage in ordinary air pressure. It is found that, by fitting the test data, the low envelop line limit of the Volt-Second area of the air gap under the UV radiation of both Xe and Hg-Xe lamp were lower than that of no UV condition. The falling amplitude of the Xe lamp's low enveloping line limit of the Volt-Second area is more dramatic than that of Hg-Xe's. The breakdown time of the air gap can be reduced remarkably because of the UV radiation, especially when the breakdown occur in the wave tail, and it turns out to be that it is not the voltage peak value's lifting that cause the breakdown time's reduce.5. UV radiation can reduce the breakdown voltage and breakdown time, the micro-mechanics of which may lies in two aspects: the UV radiation increase the probability of the negative pole's photoelectric emission, and promote the production of the excited particle in the discharge space, sequentially increase the efficiency of electric emission, when the excited particle impacts the negative pole. At the same time, it can accelerate the discharge.
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