What are the similarities and differences of voltage and current transformers?
What are the similarities and differences of voltage and current transformers?
The current transformer is called CT and the voltage transformer is called PT. What they have in common is that they work on the principle of electromagnetic induction, which is used to monitor the electrical circuit: the current of the electrical circuit is monitored through CT, which is the current source of secondary instrument and protection; The PT monitors the voltage of the electrical circuit, which is the voltage source of the secondary instrument and protection.
They differ in installation wiring: the current transformer is in series in the circuit; The voltage transformer is connected in parallel in the circuit. Their operation precautions are different: the CT secondary in operation should not be opened, which will generate high voltage and endanger the human body and damage the secondary equipment; PT in operation can not short circuit twice, short circuit will burn the voltage transformer. Because of the above reasons, switches and fuses cannot be installed in CT twice. Switches and fuses should be installed in PT secondary.
