Key Points of Operation and Maintenance in the Distribution Transformer Operation

In the process of distribution network operation, distribution transformer operation is very critical and important. When operation and maintenance staff are involved in the daily maintenance process of distribution transformers, they need to clarify the key points to help distribution transformers play their role and finally achieve stable operation.

Therefore, this paper mainly analyzes the key points of operation and maintenance in the operation of distribution transformers, hoping to provide reference and help for relevant staff.

Pad-mounted Transformer

We can provide you single phase and three phase pad mounted transformer

Dry-type Transformer

Type:Cast resin; Rated Capacity: Up to 25MVA; Rated Voltage: Up to 36KV;

Pole Transformer

TypeCSP type Frequency: 50/60Hz; Rated Power: 5~167kva

Oil immersed transformer

Frequency: 50/60Hz Rated voltage:10kv, 20kv,30kv Rated Power: 400~2500kva

Analysis of the Main Structure of Distribution Transformer

Oil-immersed distribution transformers are widely used with their own strong advantages and characteristics, and the main models include S9, S11 or S13. The actual structure of each type of distribution transformer is not very different from each other, but mainly consists of transformer case, transformer oil, iron core, decomposition switch and other major parts together.

The transformer case is mainly the overall shell of the distribution transformer, which protects the parts included inside the transformer. The inside of the case is filled with transformer oil, which insulates the transformer’s internal windings and core from the case.

Transformer oil also has a very obvious role is heat dissipation, in the distribution transformer temperature is too high, can be the first time the temperature down to within the specified range, to provide security and support for safe operation.

Table of Contents

Distribution Transformer Operation in the Process of Failure Problems that are Likely to Occur

Distribution Transformer Operation1

Temperature problem

When the distribution transformer is in the operation stage, the professional staff carries out the routine inspection of S11 type distribution transformer, there will be some hidden problems that are difficult to find, such as temperature abnormality problem.

Distribution transformer in the case of load and heat dissipation conditions or quiet temperature is unchanged, compared with the original operation of the temperature, higher, and the temperature shows a rising trend, it can be judged that the temperature anomaly problem.

In order to find out the abnormal temperature of distribution transformer at the first time, it is also necessary to use infrared imager.

Learn more aboout Dry-type Distribution Transformers Solution for Public Building

Oil leakage and oil seepage problems

distribution transformer winding2

After the transformer is put into use, there is a high possibility of oil seepage or oil leakage problems, if after careful inspection by professional staff found that oil seepage and oil leakage problems in a certain range, the transformer can still maintain normal work, but such a situation should not be ignored by staff, operation and maintenance staff need to observe the distribution transformer, if found that the amount of oil seepage and leakage is more or If the transformer continues to leak oil problem, then the operation and maintenance staff need to quickly cut off the power supply, let the transformer stop working, and then send the problem transformer to the maintenance department, by the maintenance staff to check, the first time the problem will be solved.

In addition, the transformer in the process of operation, if the oil level is too low, coupled with the lead and decomposition switch in the air completely exposed, then its insulation will continue to decline, increasing the possibility and probability of breakdown discharge problems.

A large part of the oil seepage problem in daily work is caused by broken enclosure and unstable on-load tap-changer.

Transformer appears abnormal sound problem

Distribution transformer in operation, when the power is turned on, the magnetic field changes and current and other factors will have a certain impact on it, the internal system and winding column will emit a humming sound, but if in the case of overload, the sound is very heavy.

Transformer internal including many parts, if many parts are not firmly connected and other problems, then the transformer in the process of operation will appear abnormal sound. If the noise is larger and accompanied by explosive sound, this situation is most likely because of its internal problems, such as insulation breakdown or short-circuit situation.

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Power Distribution Transformer Operation Process of Inspection and Maintenance

distribution transformer specifications4

Prevent external factors from affecting and damaging it

First of all, in the process of selecting the installation site of distribution transformer, the staff must combine the real situation to ensure that the selection of the installation site is scientific and reasonable.

Because the installation not only needs to meet the voltage requirements proposed by the user, but also needs to prevent the problem of being struck by lightning, remember not to install in the wilderness, mainly because the actual location of the installation and residents living far away, it is very easy to be targeted by some unscrupulous elements, and theft behavior.

At the same time, the remote location will also give the staff of the later maintenance and management work to bring greater impact.

Secondly, carry out inspection of the line in a regular way to avoid the problem of collision between tree branches and wires in the field and the generation of low-voltage short circuit, which will have a serious impact on the overall distribution transformer situation.

At the same time, do not add low-voltage meters to the distribution transformer, because the meter glass will be affected in the operation stage of the distribution transformer, and if it is not replaced at the first time, it is very likely that the meter will be burned in the bad weather, which will have an impact on the distribution transformer.

Finally, the impact of natural factors on the distribution transformer should not be ignored and underestimated, and the insulation cover needs to be placed at its high and low voltage end.

In the area frequented by animals or a more narrow space, adding high and low voltage insulating covers can effectively prevent things from falling on the distribution transformer junction stubs, leading to the occurrence of low voltage multiplex problems.

In addition, the distribution transformer tap changer adjustment is not in place problem will certainly increase the possibility of short circuit problems, and even lead to a burned situation, so do not allow unauthorized changes to the tap changer.

Keep on reading Ultimate Dirstribution Transformer for Guide

Increase the strength of inspection, maintenance and testing of distribution transformers

First of all, the professional staff will carefully observe the electric transformer, and then enter into the process of testing the oil temperature, and then combine with the actual situation, increase the number of inspections in those cases where the weather is very bad and the load changes a lot.

In particular, the temperature of the top layer oil in the operation of distribution transformers should be strictly controlled to below 95℃, not to make its temperature rise > 55℃, and the temperature of the top layer oil should not be often > 45℃, because such a situation will cause the deterioration of the oil to accelerate.

Secondly, increase the strength of electricity load detection. Especially in the peak period of electricity consumption, it is necessary to increase the measurement of the load of each distribution transformer, combine with the actual situation, increase the number of measurements, adjust the three-phase current imbalance of the distribution transformer at the first time, prevent the neutral line current from burning the fuse problem, protect more professional equipment, and provide help for the stable operation of the distribution transformer.

Finally, the distribution transformer is very prone to problems above, while the high and low voltage pipe sets are very likely to have a lot of dust above, so professional staff is needed to wipe and clean in time to prevent short circuit problems in the pipes in bad or humid weather, thus causing the high voltage fuse to be fused and having an impact on the normal operation of the transformer.

In addition, whether each lead of the distribution transformer insulation resistance is firm is also an important content in the inspection process, and the staff needs to pay more attention and attention to the low-voltage outlet connection, focusing their attention on whether its temperature is abnormal, whether the contact is good and other aspects.

Find more about Why Does the Power Factor of the Distribution Transformer Become Smaller?

Improve the comprehensive quality and working ability of operation and maintenance staff

The staff involved in the operation and maintenance of distribution transformers need to monitor and control them with rich working experience and solid professional knowledge, therefore, it is very crucial and important to improve the comprehensive education and working ability of operation and maintenance staff.

Only in this way can the problems in the operation of distribution transformers be found in time, and then, through regular maintenance and adjustment of taps, distribution transformers can be helped to be in good running condition.

At the same time, the power supply department also needs to bring all its role into play, popularize the most professional knowledge and principles of distribution transformers for operation and maintenance staff, emphasize the importance of safety risk control, and help staff master more methods as well as skills of distribution transformer management.

You may interested in How Can I Reduce Losses in Distribution Transformer?


In short, if distribution transformers want to achieve orderly and smooth operation, operation and maintenance staff need to bring their roles into full play, pay attention to the problems that arise in the operation process, develop a perfect method, and solve the problems properly.

In addition, it is also necessary to increase the strength of overhaul and maintenance, the first time to find the problem and properly solve it, reduce and minimize the possibility and probability of accidents, to ensure that the distribution network can be more stable in the process of operation.

It is also necessary to apply scientific methods to improve the comprehensive quality and working ability of operation and maintenance staff, and to conduct training for them in a regular and periodic way, and to combine theory and practice in the training process, so as to deepen the staff’s understanding and memory of the training contents, only in this way can the daily operation and maintenance of distribution transformers develop and move forward in a more standardized direction, and ensure that distribution transformers Only in this way can we make the daily operation and maintenance of distribution transformers develop and move forward in a more standardized direction to ensure the normal and stable operation of distribution transformers and finally realize stable power supply.

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