Measures to prevent current transformer explosions are similar to those of voltage transformers in terms of product selection, pre-operational testing, seal modification, and oil injection. The following only describes preventive measures applicable to current transformers.

    (I) Check whether the lead connector in the primary terminal of the transformer is in good contact

 The terminal of the primary terminal lead of the current transformer should be in good contact and the contact area must be kept sufficiently to prevent overheating faults in the current transformer. The L2 terminal and the expander cover should be carefully connected to prevent equipotential suspension. In addition, there should be anti-rotation measures for the secondary wire leading to the tweezers to prevent the internal leads from being broken by external operations.

    (B) abnormal test values should be identified

    When the measured value of the dielectric dissipation factor tg is abnormal before and during the operation, the tgδ should be comprehensively analyzed when the temperature changes significantly or the test voltage rises from 10kv to Um/root 3, and the tgδ increase exceeds ±0.3%. . When the results of the chromatographic analysis are abnormal, follow-up analysis should be conducted to examine its growth trend. If the data grows faster, attention should be paid to it. The accident was destroyed in the bud.

    (III) Preservation of Busbar Differential Protection Normal Input

    In order to avoid the expansion of accident coverage when a breakdown accident occurs at the bottom of the current transformer core, attention should be paid to the installation direction of the primary terminals L1 and L2 and the polarity connection of the secondary winding to be correct in order to ensure the normal input of the differential protection of the busbar. run

     (IV) Checking Short Circuit Current

According to the development of the power grid, attention should be paid to checking the short-circuit current at the point where the current transformer is located, and when it exceeds the dynamic thermal stability current value of the transformer nameplate, it must be replaced in a timely manner.

(v) On-board monitoring and infrared temperature measurement

     At present, the online monitoring projects carried out by current transformers mainly include measuring the capacitance and dielectric loss factor tgδ of the main insulation and measuring the insulation resistance and dielectric loss factor tgδ at the end of the screen insulation. Test experience shows that it is effective for detecting insulation defects. For infrared temperature measurement, some units are already under development. The existing test results show that it is effective for detecting the looseness of the current transformer's internal joints. However, it is still necessary to accumulate experience.

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