Difference Between Voltage Transformer and Current Transformer

20Dec

Difference Between Voltage Transformer and Current Transformer

 

Difference Between Voltage Transformer and Current Transformer
1.The CT can short circuit for the second time, but not open circuit; The voltage transformer may be open for the second time, but shall not be short-circuited.

2.For the load on the secondary side, the primary internal impedance of the voltage transformer is small or even negligible, so it can be considered that the voltage transformer is a voltage source. The current transformer, on the other hand, has such a large internal resistance that it can be considered as a current source with infinite internal resistance.

3.When the voltage transformer is working normally, the magnetic flux density is close to saturation value, and when it is failing, the magnetic flux density decreases. When the CT is working normally, the magnetic flux density is very low. However, when the short-circuit current at the primary side becomes very large, the magnetic flux density increases greatly, sometimes even far beyond the saturation value.

4. The voltage transformer is a special transformer used to measure the high voltage of the power network. It can convert the high voltage into a lower voltage according to the specified proportion, and then connect it to the instrument for measurement.
The voltage transformer, no matter how many volts the primary side voltage is, and the secondary side voltage is generally specified as 100 volts, in order to supply the voltage required by the voltage coil of voltmeter, power meter, kilowatt-hour meter and relay.
Electrical equipment that converts large current into small current in a prescribed proportion is called current transformer. The secondary current of the current transformer is generally defined as 5 A or 1 A to supply current to the current coil of ammeter, power meter, kWh meter and relay.

Difference Between Voltage Transformer and Current Transformer


1.The CT can short circuit for the second time, but not open circuit; The voltage transformer may be open for the second time, but shall not be short-circuited.


2.For the load on the secondary side, the primary internal impedance of the voltage transformer is small or even negligible, so it can be considered that the voltage transformer is a voltage source. The current transformer, on the other hand, has such a large internal resistance that it can be considered as a current source with infinite internal resistance.


3.When the voltage transformer is working normally, the magnetic flux density is close to saturation value, and when it is failing, the magnetic flux density decreases. When the CT is working normally, the magnetic flux density is very low. However, when the short-circuit current at the primary side becomes very large, the magnetic flux density increases greatly, sometimes even far beyond the saturation value.


4. The voltage transformer is a special transformer used to measure the high voltage of the power network. It can convert the high voltage into a lower voltage according to the specified proportion, and then connect it to the instrument for measurement.

The voltage transformer, no matter how many volts the primary side voltage is, and the secondary side voltage is generally specified as 100 volts, in order to supply the voltage required by the voltage coil of voltmeter, power meter, kilowatt-hour meter and relay.

Electrical equipment that converts large current into small current in a prescribed proportion is called current transformer. The secondary current of the current transformer is generally defined as 5 A or 1 A to supply current to the current coil of ammeter, power meter, kWh meter and relay.