How to choose the capacity of R-type transformer?

Sometimes when purchasing an R-type transformer, you may encounter the problem of uncertainty about the capacity. This is because the voltage of some equipment is special, or the purchasing personnel do not know the specific usage of the equipment. This often leads to deviations in the selection of power transformers. Today, Xiao R will talk to you about the capacity of the transformer.

R-type transformer

In the power supply and distribution system, if the harmonic content is large, it will increase the loss of the transformer, increase the temperature rise, and reduce the load capacity of the transformer. If the harmonics are serious and not effectively handled, the impact of harmonics on the load capacity of the transformer should be considered. Data shows that when the nonlinear load in the transformer power load is 20%, 40%, and 50%, respectively, the transformer capacity should be reduced by about 22%, 40%, and 45%.

If the transformer capacity is too small, it will not be able to keep up with the continuous growth of electrical equipment; the load rate of general power transformers should be around 75% to 90% of the rated capacity of the transformer. In the power supply line, the uncertain power consumption or the need to start a single large-capacity motor, as well as the simultaneous rate and growth rate of electrical equipment should also be considered.

Portable energy storage power supply, built-in high energy density lithium-ion battery, long cycle life; multi-function output interface can match the main electronic equipment on the market, large capacity and high power. Compared with small mobile power supplies and fixed power grids, safety and portability are its unique advantages, energy storage capacity: 5000kW/2MWh. Due to the large original photovoltaic power, the power generated by the photovoltaic system will not be fully used by the charging pile load, resulting in abandoned light and waste of new energy. Installing an energy storage system can store excess power generated by photovoltaics. When the power usage is large and the transformer is not enough to support the load power, the charging pile load power supply strategy adopts energy storage and power grid. When the transformer is stopped, the capacity of the small-capacity transformer should meet the power supply requirements of all primary and secondary loads to meet the emergency requirements of transformer switching operation.

When both transformers are under rated load, the capacity ratio can be greater than 3:1. Under normal circumstances, the short-circuit impedance of the large-capacity transformer should be smaller than the short-circuit impedance of the small-capacity transformer. In order to make the secondary currents of the transformers the same in phase, the impedance angle of the short-circuit impedance of each transformer must be the same. Only when the secondary currents are the same in phase can the rational use of the transformer be guaranteed.