Normal operation and isolation of precision current transformers

- Mar 15, 2019-

Normal operation and isolation of precision current transformers

When measuring the high current of the alternating current, the precision current transformer needs to be converted into a relatively uniform current in order to facilitate the measurement of the secondary instrument. The voltage on the external line of the precision current transformer is relatively high. For example, direct measurement is very dangerous. .

 

The precision current transformer plays the role of variable current and electrical isolation during operation. In operation, it is a sensor for obtaining electrical primary loop current information in secondary equipment such as measuring instruments and relay protection in the power system, and the current transformer will be high. The current is converted into a low current proportionally. The current transformer is connected to the primary system at one time, and the secondary side is connected to the measuring instrument and relay protection.

 

When the precision current transformer is in normal operation, the transformer needs the secondary side to be in an approximate short-circuit state, and the output voltage is very low. In operation, if the secondary winding is open or the primary winding flows abnormal current (such as lightning current, resonant overcurrent, capacitor charging current, inductor starting current, etc.), it will generate several thousand volts or even tens of thousands of volts over the secondary side. . This not only causes damage to the insulation of the secondary system, but also causes the transformer to be over-excited and burned, even endangering the life safety of the operating personnel.www.ctsensorducer.com