Based on the presented metallized membrane method for measuring corona leakage current of AC/DC transmission line

an on-line monitoring system is developed

which includes three components

i.e. the upper computer

the lead line voltage acquisition module

and the corona leakage current acquisition module. The corona leakage current acquisition module is located on overhead line to sample the voltage signal translated from corona leakage current on the resistor paralleled between respective bundle conductor and metallized membrane coat. The lead line voltage acquisition module is put in transformer substation for sampling the conductor voltage. Both modules are synchronized in sampling by the rising edge of PPS（pulse per second） emitted by the global position system（GPS）

and their data are sent to the public port of mobile telephone network with GPRS wireless telecommunication. The data of conductor voltage and corona currents of the bundle conductors stored in the public port are accessed by remote upper computer to calculate the corona loss of each metallized coat bundle conductor in unit length

and to further calculate the corona loss of whole line. Experimental results show that the proposed system is accurate. This study may provide a foundation for future research of corona and its effect of high voltage transmission line.