In this paper is introduced the influence of air relative humidity on corona initial voltage of coil for high voltage electrical machine.

Positive direct current (DC) corona tests of three various aluminium conductors steel reinforced (ACSRs) and smooth copper tubes were carried out in multi-functional artificial climate chamber by varying the air pressure and humidity, a computation model for evaluating the corona inception voltage on conductors was also established according to the gas discharge theory.

This paper analyzes the conductor surface potential gradient,conductor critical coronal voltage,coronal power loss of 1 000 kV AC transmission line under different bundles and different diameters of conductor section,studies the influence of high altitude on conductor critical coronal voltage,coronal power loss,and compares the adjustability of all the condu.

A method to determine corona inception voltage of icicle to ice-covered plane model by.

To research the influence of humidity on corona performance of DC conductor,an corona performance testing system for conductor corona is built; in artificial climate chamber the characteristic values of corona inception voltage and audible noise level of corona under different humidities in corona cage are measured,and the influence law of humidity on conductor corona performance is obtained.

In order to obtain altitude correction methods of corona inception voltages for different electrical devices,visible corona tests of typical DC devices used in ±800 kV transmission system were carried out at different altitudes,and contrast tests of brass conductor and LGJ-240 conductor were conducted in corona cage under different air pressures.