Study On Test Method Of Corona Loss From The HVDC Conductor In Corona Cage

The UHV DC transmission project needs to estimate the level of the corona loss of more wires. It is necessary to study a complete set of HVDC line corona loss test method based on corona cage, in order to direct a large number of HVDC conductor corona loss characteristic test, at the same time for the study of HVDC transmission project to save time and reduce unnecessary investmentIn this thesis, the test method for corona loss of HVDC conducting is studied,by using the outdoor large corona cage and wide frequency corona current measurement system. The results indicate that: In order to get more accurate measurement of the corona current, it is needed to select the appropriate sampling depth after selecting the sampling frequency, so that the sampling time should be at least 16ms. It Have no influence on the corona loss of high voltage DC conductor when the resistance wave device is installed between the circuit and the power supply. When the voltage is negative,the bipolar is 2.5 ?2.8 times of the unipolar corona loss; When the voltage is positive, the bipolar is 1.9 to 2 times of the unipolar corona loss, and the bipolar corona loss is 2.1 ?2.4 times of the positive and negative unipolar corona loss.In this thesis, the calculation method of HVDC conductor corona loss is evaluated and analyzed. The results show that the calculation results are consistent with the measurement results by using the Shockley-Ramo method, the Annenberg formula and the surface integral of the sub-conductor. However, the surface charge and electric field calculation accuracy of the surface of the sub-conductor are higher demand and more complex. So it is recommended to use the Shockley-Ramo rule and the Annenberg formula to calculate the corona loss of HVDC conductor.In the end of this thesis, the effects of temperature, humidity, sub-conductor radius, the number of conductor and the type of conductor on the corona loss of HVDC conductor are studied. The results show that with the increase of the voltage,the corona loss increases more rapidly, the greater the relative humidity and temperature, the greater the corona loss. It can effectively reduce the corona loss to a certain extent by Increase the radius of the sub-conductor and increase the number of conductor. Under the same conditions, the corona loss of molded lines is smaller than the twisted pair.