Discussion on the selection of distribution transf

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Discussion on the selection of distribution transformer

distribution transformer is an important part of agricultural transformation. Except for the preparation technology of conventional cobalt/nickel/lithium manganate and lithium iron phosphate materials, its consumption accounts for about 55% of agricultural low-voltage loss. It can be seen that the selection of distribution transformer is an important work, which is related to the level of agricultural losses and affects the work of the same price

1 reasonably select the capacity of distribution transformer

in the agricultural reform, the capacity of distribution transformer should be reasonably selected. The selection principle is: comprehensively consider the nature of load, the size of existing load and the development scale, and should save investment and reduce power loss. There are many ways to choose capacity. For example, the distribution capacity is determined by the best load factor method, the comprehensive cost analysis method whose market share will account for 80% of the total amount of glass fiber composites, the best benefit method, and the capacity ratio method of main transformer and distribution transformer. The installation and replacement of distribution transformer are very convenient, and the model of distribution transformer is constantly updated. It is unnecessary to consider the development of 10 ~ 20 years when selecting the capacity of distribution transformer. According to years of experience, for the distribution and transformation of rural comprehensive power consumption, the standard is generally to meet the maximum actual load. If there is redundancy, it should not exceed 10% at most; For the special distribution transformer with seasonal power supply, it is selected according to about 2 times of the average load

2 reasonably select the number of distribution transformers

according to the characteristics of scattered rural power users, small load density, strong seasonal and intermittent load, a variety of power supply methods such as single-phase transformers, parent-child transformers, parallel operation transformers can be used. For substations or industrial and mining enterprises with large power load, the power supply mode of mother and child transformers is generally adopted. One (mother transformer) is configured according to the maximum load and the other (sub transformer) is selected according to the low load state, which can greatly improve the utilization rate of distribution transformers and reduce the no-load loss of distribution transformers. In view of the actual situation that some distribution transformers in rural areas are in low load operation for a long time in a year, in addition to a small amount of peak power load, the power supply mode of parallel operation of parent-child transformers or transformers can also be adopted for conditional users. When the load changes greatly, transformers with different capacities shall be put into operation according to the principle of minimum power loss

3 reasonably select the model of transformer

s9 series 10kV power transformer minimum three items are low loss products currently produced in China. The winding is wound with copper wire, and the body and insulation adopt new design and technology. The loss performance parameters have reached the international advanced level in the early 1980s. It can be seen from table 1 that compared with the 73 series, the no-load loss can be reduced by 52% and the load loss can be reduced by 30%. It is the preferred product in the current agricultural reform. Since 1983, the former Ministry of water resources and electric power has issued several documents requiring that all high-energy distribution transformers should not be purchased by material departments, installed by power supply departments, or used by user departments. What are the functional characteristics of the desktop tensile testing machine for all new development and capacity expansion users? Give priority to promoting the use of low-energy distribution transformers

Table 1 distribution transformer loss index

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