Advantages: 1. When the power supply radius of the three-phase distribution transformer is too large, the load density is small, and the terminal power supply voltage is low. When affecting the normal power consumption of users, installing single-phase distribution transformers at the power supply end can shorten the low-voltage power supply radius and solve the problem of low voltage for users. 2. When the load of the three-phase distribution transformer is too heavy, appropriate branch lines should be selected and installed according to the load characteristics to transfer the load and solve the problem of capacity increase. 3. The installation of single-phase distribution transformers in residential quarters without Three-phase electric power users can shorten the low-voltage power supply radius and reduce losses. 4. The installation of single-phase distribution transformers for power supply in user sites with small load density, wide distribution and no Three-phase electric power can save investment and solve the problem of being far away from the power point.