Distribution transformer capacity how to choose

At present, in the operation of distribution transformers, there are cases of under-load operation due to excessive capacity, and overheating or even burn-out due to overload or over-current operation. This kind of device capacity choice improperly, has affected the power system power supply reliability and the economy.
step voltage regulators capacity is selected on the basis of load statistics. Since the load is not expected to be readily available, the maximum expected load is chosen. This election results, often set the capacity is too large, the power system to bring adverse effects. If the choice of economic operation, is the use of transformer copper loss and iron loss equal conditions, derive the maximum economic load factor Amorphous Core Transformer and the transformer rated capacity and maximum load ratio. As the actual operating load is not necessarily the maximum load load statistics, and the load is random, operating efficiency is variable, and its economic operating efficiency is difficult to achieve.