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Daily maintenance of on-load tap changer tester

time:2020/7/22   source:华天电力  reading:672 time

With the wide application of on-load tap-changer testers in transformers below 110kv, transformer on-load tap-changer testers play a vital role in the power system. At present, most of the voltage adjustment methods of the power grid are completed by the on-load tap-changer tester, which will push the maintenance of the on-load tap-changer tester to an important position.

Daily maintenance content and requirements of on-load tap changer tester

(1) Before the on-load tap-changer tester is put into operation, check the oil pillow, its oil level is normal, there is no oil leakage, the control box is moisture-proof, a cycle of manual operation (that is, the cycle of rising and falling), gear indicator The counter should operate correctly, the locking of the limit position should be reliable, and the interlocking of manual and electrical control should also be reliable.

(2) On-load tap-changer tester gas protection, heavy gas input and trip, light gas signal, which is consistent with the gas protection requirements of the transformer body, we usually call the main gas relay "big gas". The gas relay of the tap changer tester is called "small gas". The gas relay should be installed where it is easy to safely release gas. After installing a new on-load tap changer gas relay, the operator should release the gas when necessary (gas There is gas in the bottle).

Transformer On-Load Tap-Changer Tester.png

(3) The electrical control of the on-load tap changer tester should be correct, the power supply can be adjusted, the terminals should be in good contact, the drive motor should rotate normally, and the steering should be correct. The rated current of the fuse is 2-2.5 times the rated current of the motor.

(4) The attendant on duty automatically adjusts the voltage according to the voltage curve and voltage signal sent by the dispatcher. Each operation should carefully check the tap voltage and current changes (adjust one step each time) and make a record.

(5) When two on-load tap changer transformers are operated side by side, the tap changer is allowed to work under the rated load current of transformer 85; however, two tap changers cannot operate continuously on one transformer, and one of the other transformer The tap change operation needs to be performed after one tap change operation of a transformer is completed. Before an on-load tap changer and an unloaded tap changer are operated in parallel, the tap changer of the on-load tap changer must be adjusted to If the tap switch is the same or similar, even if the secondary voltages of the two main transformers are the same or similar, it is strictly forbidden to adjust the tap switch when the on-load tap changer and the no-load tap changer are running side by side.

(6) Oil quality supervision and inspection cycle of on-load tap-changer tester

a. Collect oil samples for compression test every 6 months. The oil pressure resistance value should not be less than 30 kV≤2.5mm. When the oil pressure is between (25-30kv)/2.5mm, the automatic pressure regulator should be stopped , When the oil pressure is less than 25 kV/2.5mm, the pressure adjustment operation should be stopped, the oil change should be arranged in time, and the oil should be changed when the operation is 2-4 years or the conversion operation reaches 5000 times.

b. Check the head spool of the on-load tap changer tester. After one year of new operation, or replace the tap 5000 times. Run for 3x4 years or accumulative adjustment times up to 10000×20000 times. However, imported equipment can be carried out in accordance with the regulations of the manufacturer, and the core inspection can be carried out in conjunction with the overhaul of the transformer.

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