How to accurately select the transformer capacity and ensure the reliable operation of power transmission? If the transformer capacity is too large, it will form a “big horse car”, which will not only increase equipment investment, but also make the transformer long-term.
In the no-load state, the reactive power loss is increased; if the transformer capacity selection is too small, the transformer will be overloaded for a long time and the transformer will be easily burned.
The load factor of the transformer is the highest between 0.5 and 0.6, and the capacity of the transformer is called the economic capacity. If the load is relatively stable, the continuous production situation can select the transformer capacity according to the economic capacity; for the power only to the irrigation and drainage
The special transformer for power supply can generally select the capacity of the transformer according to the power of the nameplate of the asynchronous motor. The starting current of the general motor is 4~7 times of the rated current. The transformer should be able to withstand the impact and directly start the electric motor.
The capacity of the largest one in the machine should generally not exceed 30% of the transformer capacity. It should be pointed out that the special transformer for irrigation and drainage should not be connected to other loads in order to stop the operation in time during the non-drainage period and reduce the loss of electric energy.
For the selection of the capacity of integrated power transformers such as power supply lighting and agricultural and sideline products processing, it is necessary to consider the simultaneous power of the electrical equipment, and the capacity of the transformer can be selected according to the actual maximum load that can occur 1.25 times. According to rural power grid
The characteristics of user dispersion, low load density, seasonal load and strong gap can be adjusted. The variable capacity transformer is a transformer that can adjust the capacity without load according to the load. It is suitable for the load season.
Use where the sexual change is obvious.
For industrial and mining enterprises with large substation or large electric load, the mother-child transformer power supply mode 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.
Improve the utilization of distribution transformers and reduce the no-load loss of distribution transformers.
In view of the fact that some transformers in rural areas have a low-load operation state for a long time except for a small amount of peak power load in a year, for the conditional users, the power supply mode in which the mother-child transformer or the transformer is operated in parallel can also be used. Negative
When the load changes greatly, the transformers of different capacities are input according to the principle of the lowest power loss.