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Analysis of different transformers failure

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Update time : 2018-04-02 14:28:14
The power supply in today's world has become an indispensable part of industry, life and science and technology. The main circuit breakers and these circuit breakers play an important role in the end, the transformer failure is usually accompanied by arcing and discharge and severe combustion occurred, followed by short-circuit or other electrical power equipment failure occurs, ranging from just machine stop Turn, lighting completely extinguished, in serious cases there will be a major fire and even personal injury. Therefore, how to ensure the safe operation of the transformer has attracted the attention of all countries in the world.
Mr. William Bartley, Chief Engineer of Engineering Department of HSB, USA, is mainly responsible for the analysis and evaluation of large-scale power equipment, especially generators and transformers. He is also responsible for investigation of major accidents, improvement of maintenance procedures and research on new detection technologies. However, in the modernization of our country, the safe operation of the power industry also plays a crucial role. For the power safety failure, we also made a detailed analysis to achieve the purpose of serving the power sector.
Transformer different failure analysis:
Transformer used in different departments, the failure rate is different. To analyze the risk of transformer failure, the user can be divided into 11 separate types:
(1) Cement and mining;
(2) Chemicals, oil and natural gas;
(3) Power sector;
(4) food processing;
(5) medical treatment
(6) manufacturing
(7) Metallurgical industry;
(8) Plastic;
(9) printing industry;
(10) Commercial buildings;
(11) Pulp and paper industry.
According to HSB's Rick Jones risk management approach, "risk" is defined as the frequency and extent of loss. The degree of loss can be defined as annual average gross loss, and the frequency of occurrence (or probability) can be defined as the average number of faults divided by the total. So, for each given individual group:
Frequency = number of faults / number of transformers in the group
(For example, if there are an average of 10 failures per year, with 1,000 users in a given independent group, the probability of failure anywhere in the group is 0.01 / year.) Therefore, the product's fault frequency and The degree of transformer risk divided by the user. (Risk = Frequency × Degree).
Frequency-level "distribution" of transformer risk in 10 independent groups in 10 years. In each set of curves, the X-axis represents the frequency and the Y-axis represents the degree (or average loss). The relationship of X-Y forms a risky coordinate system. The slashes are called risk equivalence curves (for example, the probability of 0.1 for $ 1,000 and the likelihood of $ 10,000 of 0.01 can be considered equally risky). The quadrant in the upper right hand corner of the coordinates is the most risky area.
When considering the frequency and degree, the power sector is at the highest risk, while the metallurgical industry and manufacturing are second and third respectively.
A variety of service life transformer failure
According to the transformer designer's statement, in the "ideal conditions" the service life of the transformer up to 30 to 40 years, it is clear that in practice is not the case. In the 1975 study, the average transformer life span was 9.4 years. In the 1985 study, the average life of the transformer was 14.9 years. There is usually a potted curve showing the initial failure rate as well as the aging result at the right end. However, the failure statistics show that the service life of the transformer is not unpredictable. This shows statistical data on the useful life of the study, which can be used to determine the time and cost of periodic inspection of the transformer.
The service life of transformers in the power industry deserves special attention. After World War II, the United States experienced a phase of rapid industrial development and led to the large-scale development of basic industries, especially the power industry. Most of the equipment installed in the 1950s and 1980s, designed and in operation, is now aging. According to the U.S. Department of Commerce, the power industry peaked in the installation of new equipment between 1973 and 1974. Today these devices have been in operation for nearly 25 years, so special attention must be given to the possibility of failure of installed transformers.