Corona Discharge Ion Mobility Of Gas Based On Needle-ring Model In Different Altitudes

With voltage classes of transmission line constantly improving in China, the loss of corona has become one of the key technical problems. Ion mobility i s an important factor about the corona loss of the transmission lines in different altitudes. Nowadays, the ion mobility applied to calculate the corona loss is always a constant in the world. Actually the ion mobility varies as different altitudes. Hence, it’s very important for the research of the corona loss of the transmission lines to study and summarize the ion mobility discharged by gas corona in different altitudes and get the parametric model of ion mobility varying as Pressure.In this paper, I designed a measurement platform aimed at ion mobility of corona discharge independently on the basis of drift tube measure. The measurement platform improves the way of ion gate’s open-closing and analyzes both amplification of acquisition signal and inhibition of disturban ce signal. In the experiment, using measurement platform that can simulate electrode model of different altitudes measures needle ring corona discharge current intensity, and get the volt-ampere characteristic curve about the relationship between the disch arge current intensity change with altitudes and corona discharge with the change of altitudes. The discharge rule in consistent with self-maintained discharge formula, verify the feasibility of needle loop’s corona discharge, and fully prepares for the measurement of ion migration situation.Based on the measurement platform that can stimulate ion migration in different altitudes, I got the wave of H+(H2O)n in air and made relevant analyses. B y several measurements, the ion migration time of the air positive polarity corona discharge is got, and the rate of ion migration is 1.229cm2V-1S-1. On the basis of the mentioned experiment analyses, using ion migration tube of needle ring corona discharge model to measure the relationships between the time of ion mig ration produced by oxygen, nitrogen or other different electric polarity and pressure of the integral altitude point from 0 to 6000 meters, I found out the relationships between ion migration time and different altitudes, compared these relation curves and analyzed their differences. These relation curves provide some references for measuring the corona loss of the transmission lines in different altitudes in engineering practice.