In order to study the cause of PT high voltage fuse blow thoroughly in the electrical power distribution system,massive physical analogue experiments are tested.

Power system operation and experimentation show that, in a non-grounded distributionnetwork, two main problems are in relation to voltage transformer(PT): one is feroresonanceand the other is blowing-out of the high-voltage PT fuse.

In the 10-35kV isolated neutral distribution network, the high voltage fuse which protect the potential transformer often break because of single-phase earth fault, even the potential transformer may be destroyed.

Cause Analysis of High-voltage Fuse Blow in Power Distribution System and Its Countermeasures;

By analyzing the structure of the high-voltage current-limiting fuse,a simple equivalent model of the high-voltage current-limiting fuse was built using the finite element method.

High-voltage current-limiting fuse is a very common protector which is used to protect generator、transformer and other important equipment.

At the mean time of the high-voltage current-limiting fuse cutting off the current, the fuse will melt and boil away, and it will generate electric arc with high temperature and high pressure.