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The Function of Instrument Transformer in Relay Protection

 

The Function of Instrument Transformer in Relay Protection

Relay protection devices are weak current devices, can not be directly connected with the high voltage strong current system, in order to isolate the high voltage, generally need to use instrument transformer.
Common instrument transformers include current transformers and voltage transformers.

Current transformer:
Current transformer is a kind of instrument current converter. Its function is to change the large current in the primary circuit of power system into the standard small current in the secondary circuit.
At present, electromagnetic current transformers with iron cores without air gaps are more commonly used in the power system. The secondary side of the transformer is grounded to ensure the safety of secondary equipment and staff.
The secondary winding of current transformer should never be open circuit in operation, so as not to endanger the safety of equipment and staff.

Voltage transformer:
Voltage transformer is the instrument transformer used to change the high voltage in the primary circuit of the power system into the standard low voltage in the secondary circuit for protection or measurement.
Similar to current transformer, it mainly plays the role of isolating and transforming voltage. Voltage transformers are mainly divided into electromagnetic voltage transformers and capacitive voltage transformers.
In operation, the secondary winding of the voltage transformer should not be short-circuited, otherwise it will produce a large short-circuit current, which will burn the transformer and endanger the safety of equipment and staff.

The Function of Instrument Transformer in Relay Protection


Relay protection devices are weak current devices, can not be directly connected with the high voltage strong current system, in order to isolate the high voltage, generally need to use instrument transformer.

Common instrument transformers include current transformers and voltage transformers.


Current transformer:

Current transformer is a kind of instrument current converter. Its function is to change the large current in the primary circuit of power system into the standard small current in the secondary circuit.

At present, electromagnetic current transformers with iron cores without air gaps are more commonly used in the power system. The secondary side of the transformer is grounded to ensure the safety of secondary equipment and staff.

The secondary winding of current transformer should never be open circuit in operation, so as not to endanger the safety of equipment and staff.


Voltage transformer:

Voltage transformer is the instrument transformer used to change the high voltage in the primary circuit of the power system into the standard low voltage in the secondary circuit for protection or measurement.

Similar to current transformer, it mainly plays the role of isolating and transforming voltage. Voltage transformers are mainly divided into electromagnetic voltage transformers and capacitive voltage transformers.

In operation, the secondary winding of the voltage transformer should not be short-circuited, otherwise it will produce a large short-circuit current, which will burn the transformer and endanger the safety of equipment and staff.