Within the protected transformer short-circuit failure caused by the saturation

Occurred in the area to be protected transformer saturation caused by short-circuit fault is not easy with the differential and restraint currents ratio distinction. This is because the differential and restraint currents measured value will be affected, and they will immediately satisfy the protection ratio of operating conditions. At this time, the ratio of the operating characteristics of the differential  Electric energy meter  effective, the failure rate differential protection features to meet operating conditions.
That occurred outside the protected transformer fault, it produces a large short-circuit currents caused through saturation will have a great false differential current, which in the case of each measuring point is not the same saturation is more serious. If the magnitude of the resulting operating point falls triggered by the ratio of the operating  electric transformer  of the differential protection zone, and do not take any measures to stabilize the differential protection ratio, the ratio differential protection will malfunction. Calculated according to Kirchhoff's current law to get the amount of current transformers on each side of the differential current, basic balance at the beginning of a short time, only the current imbalance will produce a smaller, until saturation will produce a greater differential current, causing the transformer differential protection. How to identify the current transformer saturation .