New or overhauled 1000kva transformers should be subjected to an impact test before being put into operation
- Categories:Industry Dynamics
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- Time of issue:2022-10-05
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(Summary description)Why should the new 1000kva transformer or the overhauled 1000kva transformer be subjected to an impact test before it is officially put into operation? How many times do you usually hit?
New or overhauled 1000kva transformers should be subjected to an impact test before being put into operation
(Summary description)Why should the new 1000kva transformer or the overhauled 1000kva transformer be subjected to an impact test before it is officially put into operation? How many times do you usually hit?
- Categories:Industry Dynamics
- Author:
- Origin:
- Time of issue:2022-10-05
- Views:0
Why should the new 1000kva transformer or the overhauled 1000kva transformer be subjected to an impact test before it is officially put into operation? How many times do you usually hit?
Answer: The reasons for the impact test of the new 1000kva transformer or the overhauled 1000kva transformer before it is officially put into operation are as follows:
(1) Check whether the insulation strength of the 1000kva transformer can withstand the impact of full voltage or operating overvoltage.
When the no-load transformer is opened, a small excitation current is cut off, and it may be forced to extinguish before the excitation current reaches the zero point. Due to the blocking phenomenon of the circuit breaker, the 1000kva transformer with inductive properties generates an operating overvoltage, which is divided by In addition to the switching performance, transformer structure, etc., the grounding method of the neutral point of the transformer also affects the overvoltage of the no-load transformer. Generally, the ungrounded transformer or the transformer grounded by the arc suppression coil, the overvoltage amplitude can reach 4-4.5 times the phase voltage, and the transformer whose neutral point is directly grounded, the operating overvoltage amplitude generally does not exceed 3 times the phase voltage. This is also the reason why the neutral point of the transformer for the impulse test is required to be directly grounded.
(2) When the no-load transformer is put into operation, an inrush current will be generated, and its value can reach 6-8 times of the rated current. Since the inrush current will generate a lot of power, the impact test is to assess the mechanical strength of the transformer and whether the relay protection will malfunction under the action of the large inrush current.
Number of impact tests:
The new 1000kva transformer needs to be impacted five times. After the overhaul, the transformer needs to be impacted three times.
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