How to Choose Transformer?

May 25,2022

How to accurately select the transformer capacity to ensure the reliable operation of power transmission? If the transformer capacity is too large, it will form the phenomenon of a "big horse pulling a small car", which will not only increase the equipment investment, but also make the transformer in a no-load state for a long time and increase the reactive power loss; If the transformer capacity is too small, the transformer will be in overload state for a long time, and it is easy to burn the transformer.




The load rate of the transformer is between 0.5 ~ and 0.6, and the efficiency is the highest. At this time, the capacity of the transformer is called economic capacity. If the load is relatively stable and continuous production, the transformer capacity can be selected according to the economic capacity; For special transformers that only supply power to power loads such as drainage and irrigation, generally, the capacity of the transformer can be selected according to 1.2 times of the nameplate power of the asynchronous motor; Generally, the starting current of the motor is 4 ~ 7 times of the rated current, and the transformer shall be able to withstand this impact. The capacity of the largest motor directly started shall not exceed about 30% of the transformer capacity. It should be noted that the special transformer for drainage and irrigation should not be connected to other loads in general, to shut down in time in the nondrainage and irrigation period and reduce power loss.


For the selection of comprehensive power transformer capacity for power supply, lighting, and agricultural and sideline products processing, the simultaneous power of electrical equipment shall be considered, and the transformer capacity can be selected according to 1.25 times the actual maximum load. According to the characteristics of scattered users, small load density, strong seasonality, and gap of load in the rural power grid, the adjustable capacity transformer can be adopted. A capacity regulating transformer is a kind of transformer that can adjust the capacity without load according to the load. It is suitable for places with obvious seasonal variations of load.


For substations or industrial and mining enterprises with large power loads, 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 the distribution transformer and reduce the no-load loss of the distribution transformer.


Given the actual situation that some distribution transformers in rural areas are in low load operation for a long time in addition to a small amount of peak power load in a year, 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.


Searching for a Transformer supplier, wholesaler, manufacturer from China, you can get high-quality products at a nice price.