The difference in the principle of action between a voltage transformer and an electrical current transformer

1) Electrical Current Transformer can be short-circuited for the second time, but must not be open; the voltage transformer can be opened for the second time, but must not be short-circuited;

2) Compared with the load on the secondary side, the primary internal impedance of the voltage transformer is so small that it can be ignored. It can be considered that the voltage transformer is a voltage source; while the primary internal resistance of the Electrical Current Transformer is so large that it can be considered It is a current source with infinite internal resistance.

3) The magnetic flux density of the voltage transformer is close to the saturation value during normal operation, and the magnetic flux density decreases when the fault occurs; the magnetic flux density is very low during the normal operation of the Electrical Current Transformer, and the short-circuit current on the primary side becomes very large when the The flux density increases greatly, sometimes even far beyond.