Calibration device for toroidal current transformer and its ratio test method

- Jun 15, 2019-

There are many devices required to verify the toroidal current transformer, such as the transformer calibrator, which is mainly used to measure the error between the standard transformer and the transformer under test, and display the working current; the standard current transformer: used in the transformer test As a standard, the accuracy is generally two or more higher than the measured height. The design has multiple ratio taps to adapt to the verification of different transformers. 

There is also a current riser, which cooperates with the voltage regulator to match various required test currents; the load box simulates the actual working state of the measured transformer; the voltage regulator is used to adjust the test current, generally with protection and switching, etc. Installed in a single operating console, the two regulators are coarsely adjusted and fine-tuned to meet the adjustment fineness.

As a key equipment in the power system, the toroidal current transformer is very important for its electrical performance test. For the toroidal current transformer, the ratio test is an indispensable test item. The current transformer ratio is related to the measurement. The accuracy and reliability of the protection. 

The field current ratio test of the toroidal current transformer generally adopts the current method. The current method is used to measure the current transformer ratio. In fact, it is the actual operating condition under the condition of rated current. It is an ideal test method with high measurement accuracy. However, with the continuous development of the power system, the capacity of a single generator is getting larger and larger, and its outlet current has reached tens of thousands of