Reasons for the action of transformer differential protection

Transformer differential protection is an important protection measure to ensure the safe and stable operation of the transformer. Its main function is to monitor the differential current of the transformer during operation. Once it is found that the differential current exceeds the set range, the differential protector will be triggered to disconnect the faulty line in time and protect the transformer and power system from losses.

There are many reasons for the operation of the transformer differential protector, which mainly include the following aspects:

1. Short-circuit fault of the internal winding of the transformer
When the internal winding of the transformer is short-circuited When this occurs, the differential current will exceed the set value, causing differential protection to operate. This fault is usually caused by insulation aging, short circuit or poor contact of the transformer winding.

2. External fault of transformer
External fault of transformer is also an important reason for differential protector operation. External faults generally refer to short circuit or poor contact of the transformer output line, or transformer output circuit breaker failure and other factors. At this time, if the differential protector is set appropriately, the fault can be detected in time, thereby avoiding the expansion of the fault.

3. Malfunction or false signal
Because of its high sensitivity, the differential protector may sometimes be triggered by malfunction or false signal, such as external factors such as lightning strikes and transients. interference, or signal changes caused by overload of the equipment itself, load changes and other factors. At this time, the differential protector needs to be adjusted by setting reasonable parameters such as sensitivity and delay to avoid malfunctions or false signals.

4. Failure of the differential protector itself
Since the differential protector itself is also an electrical device, it may also fail during long-term operation. At this time, the differential protector needs to be maintained and inspected regularly to avoid malfunctions or false signals caused by problems with the differential protector itself.

5. Transformer ground fault
Transformer ground fault refers to faults related to the transformer ground, such as a short circuit between the transformer winding and the ground, or the ground resistance exceeding the normal range. At this time, the differential protector will also be triggered to cut off the faulty line in time.

In summary, there are many reasons for the operation of the transformer differential protector. The setting of the differential protector, the reasonable adjustment of parameters such as sensitivity and delay, and the daily maintenance and inspection of the transformer are all factors. Important measures to ensure safe and stable operation of transformers.