How to confirm the saturation of Power Current Transformer

In order to study the working characteristics of the Power Current Transformer and confirm whether it can saturate and affect the correctness of the maintenance operation while maintaining external faults from large currents, it can be tested by some test methods. These measures are described below. Obviously, the direct test method is to accept a practical load on the secondary side, apply a current from the primary side, and observe the secondary current to find the saturation point of the Power Current Transformer. However, regarding the maintenance-level Power Current Transformer, its saturation point may exceed 15 to 20 times the rated current. When the Power Current Transformer becomes larger, it may be difficult to test it in the field. In addition, it can also measure the saturation point of the Power Current Transformer through a volt-ampere characteristic test.

As mentioned earlier, the saturation of the Power Current Transformer is the saturation current of the Power Current Transformer calculated due to the excessive magnetic flux density of the iron core. The test method of the volt-ampere characteristic is: the original side is disconnected, the current passes through the secondary side, and the voltage drop on the secondary side winding is measured. Since the primary side of the Power Current Transformer is open, the primary side current has no demagnetization effect, and the iron core is easily saturated at a small current. Therefore, the volt-ampere characteristic test does not need to increase the large current, which is relatively easy to complete in the field.