In polarity inversion of direct current power transmission, the puncture voltage drops when there is a injection charge at polar terminal.
Accordingly the writer studied the effect of space charge by iniection charge on insulating puncture voltage, ...
In polarity inversion of direct current power transmission, the puncture voltage drops when there is a injection charge at polar terminal.
Accordingly the writer studied the effect of space charge by iniection charge on insulating puncture voltage, and the puncture character of material which is difficult in injection.
The results are as follows:
1) The sample injected charge showed that there was a drop of puncture voltage in polarity inversion.
2) The ratio of puncture voltage drop in polarity inversion coincided with its theoretical expression.
Therefore, we need to develop a material which suffers little injection charge at high temperature.