Please help analyze the reasons for the tripping of the 35KV switch
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Our company has two transformers (10,000 KVA and 5,000 KVA) operating in parallel. Yesterday, a new 10 KV line was set to be put into use; all tests on this new line were completed, and it was not loaded at the time. When power was supplied and the switch was closed, the entire 35 KV main switch tripped, as did the outlet connected to the 5,000 KVA transformer. The 5,000 KVA transformer also triggered a heavy gas alarm. But it was operating normally before this new 10KV line was installed. I don’t quite understand high voltage; could an expert help analyze the reason?
Ahah, the switch for this marine unit has tripped; the main cause is a transformer failure (a severe gas fault requires the switch to trip!) Generally, in the event of a transformer failure, it is necessary to simultaneously trip the switches on both the high-voltage side and the low-voltage side. Based on this sailor’s brief description, for an unloaded circuit that is in the closed state, if there are no faults with the switches and circuits connected to it, the main problem is likely an internal fault in the transformer! The power side and the output side of the transformer must be isolated, and the current condition of the transformer must be thoroughly checked (such as transformer inspection and testing, inspection and testing of the transformer oil, etc.; if there is a winding fault, it will be necessary to disassemble the transformer core for major repairs).
The final inspection indeed confirmed that the transformer was burned out; chromatographic analysis of the transformer oil indicated arcing between the switches. I’m wondering if there might be an issue with the quality of the transformer itself Connecting an unloaded circuit shouldn’t damage the transformer, right?
Generally speaking, closing a circuit with no load will generate some operating overvoltage, especially in 10KV feed lines; however, this usually does not affect the safe operation of the main transformer The key is to carefully inspect the interior of the transformer to check for any defects or potential problems (through core inspection). It could also be due to shortcomings in the transformer’s manufacturing or assembly, or as a result of internal degradation over time; therefore, it is not yet possible to definitively determine or rule out the cause of the fault. Additionally, it is recommended to check and test the performance of the zinc oxide arrester on the feed line to ensure it is in good condition
It has been removed and taken back to the factory for core inspection; thanks for the suggestion!