About the setting of quick-break protection of transformer
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Regarding the setting of the quick-break protection of the transformer, the manual says that the quick-break protection of the transformer can avoid the super-transient short-circuit current of the three-phase short-circuit current on the low-voltage side, but the value set in that way is very large. . . How should it be generally adjusted?
The quick-break protection setting is very large. Didn't you calculate and set it according to the super-transient short-circuit current that avoids the three-phase short-circuit current on the low-voltage side? If you think the setting value is too high and lower it, then a feeder circuit behind the busbar below the transformer will be short-circuited (basically the same short-circuit current as a short-circuit on the low-voltage side of the transformer), your transformer will also trip. You should only jump the feeder, but now you have jumped the incoming transformer, stopping the entire busbar. Do you think it is appropriate?
The short-circuit current is calculated according to the per unit value method, and then adjusted according to the wiring method, and then tested to ensure reliability, selectivity and other characteristics.