Abstract: Transformers are one of the most common electrical equipment in the distribution network. They are also the most exposed electrical equipment in the management of the grassroots. As a grassroots management personnel, the normal operation of transformers is not only related to grid security, but also affects the image of power companies in the hearts of users. The Xiugu Power Supply Station where I am located is responsible for more than 22,000 power supply tasks within the county. However, since the restructuring, there has not been a transformer burning accident for more than 10 years, which not only saves money for power supply companies, but also protects users. A satisfactory answer sheet was provided for continuous use of electricity. Let me talk about my experience in transformer maintenance.

1. Strengthen daily inspections, maintenance and regular testing

In accordance with the division of labor of the Taiwanese management personnel, in addition to the regular inspection work of transformers, we also require management personnel to strengthen daily inspections and make certain responsibilities. The key inspection contents include:

(1) Look at the appearance. Mainly check whether there is oil leakage outside the transformer, whether there is smoke or discharge of parts. If the transformer casing is not tightly welded or the gasket is not solid, the transformer may leak oil. If the oil level is too low, the insulation protection will be lost, resulting in discharge between the conductive parts or between the conductive part and the outer casing. In severe cases, the transformer will be burnt. Therefore, the fault should be eliminated and the oil should be replenished in time to ensure that the oil level is maintained at 1/4-3/4 of the oil mark. For parts loose, poor contact or even discharge, the transformer drop insurance should be disconnected in time to eliminate hidden dangers.

(2) Listen to the sound. A properly functioning transformer will emit a uniform and subtle humming sound. When the transformer has a different nature, the sound will change. At this time, measures should be taken according to the situation to find the cause of the failure.

(3) Check the dust on the distribution oil and high and low pressure casings, clean and wipe the oil and dust in time to prevent the weather from being wet or rainy, causing the casing to be short-circuited and the high-voltage fuse to be blown. It does not work properly. I asked the inspectors to clean at least every 2 months.

(4) Observe the oil color and regularly check the oil temperature, especially the weather with large load change, large temperature difference and bad weather. The top oil temperature in the oil-immersed distribution transformer operation should not exceed 95 °C. To prevent excessive degradation of the windings and oil, the temperature rise of the top oil should not exceed 45 °C.

(5) Shake the insulation resistance of the distribution transformer and check whether the leads are firm. Pay special attention to whether the contact at the low-voltage outlet connection is good and the temperature is abnormal.

(6) Strengthen the measurement of the electric load. During the peak period of power consumption, strengthen the load measurement for each distribution transformer, increase the number of measurements if necessary, and timely adjust the distribution transformer of the three-phase current unbalance to prevent the neutral line. If the current is too large, the lead wire is broken, causing damage to the user equipment and damage to the distribution. The connection group is the distribution of Yyn0. The three-phase load should be balanced as much as possible. It should not be powered by only one phase or two phases. The neutral current should not exceed 25% of the rated current of the low-voltage side, so as to ensure that the distribution is not overloaded or unbiased. run.

(7) Regularly check and replace one fuse. It is strictly forbidden to replace the fuse with aluminum wire. It is well known that one fuse protects the system, the secondary fuse protects the transformer, and the fuse selection must be compatible with the transformer capacity.

2. Prevent external damage:

(1) Reasonably select the installation location of the distribution transformer. The installation location should be as close as possible to the load center, and the power supply radius should be controlled within 0.5km. At the same time, it is necessary to avoid installing it in a place that is easily hit by lightning or low water. Because it is located in the county seat, there are many transformers at the intersection. In order to reduce the accident of the car hitting the tower, all the bumper strips are attached to the poles along the road.

(2) Try to avoid installing low-voltage metering box on the distribution transformer. Due to long-term operation, the glass of the metering box is damaged or the damaged low-pressure pile head can not be replaced in time, causing the transformer to be damaged due to rain and other reasons. . More than 95% of the public distribution transformers in our company are all equipped with JP cabinets, which play a very good role in protecting the safe operation of the transformer.

(3) It is not allowed to adjust the tap-changer privately to prevent the tap-changer from being adjusted to the point where the phase-to-phase short circuit causes the distribution transformer to burn out.

(4) Install an insulating cover at the high and low voltage end of the transformer to prevent natural disasters and foreign objects from being destroyed. Install high and low voltage insulation covers in the narrow forest areas and forest areas where animals enter and exit frequently to prevent the distribution transformers from dropping on the wiring piles. Short circuit the low voltage and burn the distribution.

(5) Regularly inspect the line and cut down the line channel to prevent the branch from hitting the wire and causing a low voltage short circuit to burn the distribution transformer.