Difficulties in Maintaining Balanced Load on a Transformer
The distribution transformer supplies power to the domestic and/or commercial consumers. In practice, it is seen in which all consumers will not switch on their entire connected load at the same instant of time. The switching of load will vary with time and also along with the requirement of the consumer. This is expressed in terms of the diversity factor. If it is equivalent to 1, it means in which all the consumers are in requirement of their entire linked load at the similar instant of time. In practice, the diversity factor ranges between 2 and 3. If diversity factor is more, then there is a greater possibility in which the load on each phase of the distribution transformer will vary and not be equal.
Present; consider an Electric Utility that is supplying power to little industrial consumers. In that case, the transformer will be supplying to more three phase loads than single phase loads. Then the diversity factor for small industrial consumers will be less compared to the domestic/commercial consumers. For huge industrial consumers, the diversity factor will be even less. But some degree of unbalanced loading will still remain on the transformer. The task of distribution utility is to decrease this degree of unbalanced loading.