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SuharDry type What is the wavelength of oil immersed transformer?
Therefore, in the operation prevention and regulation of relay protection dry-type transformer, it is necessary to find the short-circuit fault point according to the fault situation, lock the fault point,BartkenDry type transformer size, and analyze the short-circuit fault types of relay protection dry-type transformer. At the same time, if all fields are clear, the maintenance work of employees will be carried out smoothly,BartkenTransformer 5000KVA price, and the harm will not expand to a greater extent.
Bartken.During the operation of the transformer, the resistance value of the grounding wire shall be measured accurately every two years.
Generally speaking, the ignition emergency treatment method of oil immersed transformer is mainly to disconnect the oil immersed transformer, disconnect the switching power supply on each side, the generator set must be disassembled first.
.(I) the distance between the external contour of 10kV and below dry-type transformer and the surrounding guardrail or courtyard wall shall take into account the convenience of transportation and repair of dry-type transformer, and the distance shall not be less than 1m; At the angle with actual operation, a spacing of more than 2m shall be reserved; If metal fence is selected, the metal fence shall be grounded and a warning sign shall be hung at a prominent position.
The dry-type transformer is composed of two winding resistances, resulting in four wiring groups: & ldquo; y Y & rdquo;, & ldquo; D, Y & rdquo;, & ldquo; y, D & rdquo; and & ldquo; D, D & rdquo;. In China, only & ldquo; y, Y & rdquo; and & ldquo; y, D & rdquo; are selected. Because there are also two types of Y-connection with neutral line and without neutral line. If there is no neutral line, it will not be upgraded. All marks show that with neutral line, it will not be upgraded The letter N after the English letter Y indicates that the neutral line has transformer grounding wire. Yn0 wiring group,BartkenHow much is a 250kVA box transformer, when UAB and UAB overlap, the minute hand points to 12. & ldquo; 12 & rdquo; in the new wiring group, it is indicated by & ldquo; 0 & rdquo.
The time difference between different steps of three-phase power switch of switching power supply shall be less than 10ms, the closing shall be maintained by high-voltage arrester, and the neutral line of transformer shall be reliably grounded (it shall be grounded immediately).
If the volume of power transformer is too small, the transformer will be overloaded for a long time and it is easy to destroy machinery and equipment. Therefore the rated capacity of the transformer should be selected according to the power consumption, which is not suitable for too large or too small.
How to select dry-type transformer
The key reason for oil leakage is that there are defects in cast iron parts
how.It will also produce many faults, effectively deal with various faults of oil immersed transformer, make full use of the performance indicators and advantages of oil immersed transformer, and continuously improve the safety factor of oil immersed transformer. Ignition is a common fault of oil immersed transformer. The key fault of oil immersed transformer is short-circuit fault, and short-circuit fault is more general.
After no-load test run is normal for 24h, it can be transferred to on-load operation, and the load shall be gradually increased from 25%, 50% and 75% by grade.
If the power transformer stops running for more than 72h (if the allowable time should be reduced when the ambient humidity is & amp; gt; 95%), it should be insulated before putting into use, and accurately measured with a 2500V grounding megger. The insulation resistance from the primary side to the secondary side and the ground should be ^ 300mfl, the insulation resistance from the secondary side to the ground should be ^ 100mh, and the insulation resistance from the iron core to the ground should be & amp; gt; 5mfl (note that the grounding device piece should be removed).
The long-term overload of power transformer will slowly cause the scalding and insulation aging of solenoid coil, resulting in short circuit between coils, two-color short circuit or short circuit on the ground, resulting in the ignition of power transformer. Therefore, the insulation compressive strength of power transformer shall be tested before installation and operation, and overload is not allowed in the whole process of operation.
Statistics.The capacity and working voltage are different. The dry-type transformer is generally suitable for distribution equipment. The capacity is generally below 2000kVA and the working voltage is below 35KV, which also ensures the rated voltage of 110kV; Oil immersed transformers are generally suitable for distribution equipment.
The grounding resistance of, high voltage and bottom voltage shall not be less than 70% (10m & omega;) of the original value. The difference between the three-phase mean value of winding resistance measurement at the same temperature shall not exceed 2%, which shall not exceed 2% compared with the last accurate measurement result.
Different diversion methods, dry-type transformers mostly use silica gel waterproof casing, while oil transformers mostly use porcelain waterproof casing;
Bartken.The representative mode of connection group of dry-type transformer is: English capital letters indicate the wiring on the primary side (or primary side), and English letters indicate the wiring on the secondary side (or secondary side). Y (or y) is star wiring and D (or D) is triangular wiring.
When the transformer is put into operation, if the tap changer is not in time a great & ldquo; Tweet & rdquo; The high-voltage fuse is broken when the noise is serious; If the tap changer is defective, it will cause mild & ldquo; Squeak & rdquo; Corona discharge sound, once the load increases, it is likely to burn the circuit breaker of the tap changer. In case of such situation, power off immediately for maintenance.
In relay protection dry-type transformer, it will affect the whole power circuit