The current urban and rural power grid upgrades are essentially distribution network upgrades with loss reduction as the primary objective. Through rational layout of power supply points, network upgrades, and transformer selection, these upgrades effectively address the hot issues of great concern to the government and power departments, achieving the goal of reducing network losses. To solve the common problems of high line loss rates and poor voltage quality in low-voltage distribution networks, Jiangsu Provincial Power Company proposed a general approach: 10 kV lines extending deep into load centers, and small-capacity, densely distributed distribution transformers. Following the principle of shortening the low-voltage power supply radius, a new single-phase distribution transformer power supply mode was adopted, opening up a new approach for power supply in areas with low load density and wide user distribution. A typical configuration of single-phase distribution transformers is characterized by their small size and light weight, allowing for pole-mounted installation, convenient installation, and reduced material costs in the distribution area. This maximizes their penetration into load centers, shortens the low-voltage network power supply radius, and reduces losses. Based on the installation requirements of distribution transformers and the actual situation of the Suqian power grid, we have summarized a typical configuration for single-phase distribution transformer installation: single-phase distribution transformer, low-voltage switch, reactive power compensation device, distribution load monitoring system, etc. 2. Selection of Installation Location and Installation Method for Single-Phase Distribution Transformers: Single-phase distribution transformers can be installed using a single-pole suspension method, with 12m heavy-duty concrete poles or 15m concrete poles selected. Location Selection: Research shows that the installation location of single-phase distribution transformers is less restricted by geographical factors and more constrained by load characteristics. Generally, when the power supply radius of a three-phase distribution transformer is too large, resulting in low voltage at the end of the supply line and affecting normal power consumption, installing a single-phase distribution transformer at the end of the power supply line can cut off the low-voltage network, shorten the low-voltage power supply radius, and solve the problem of low voltage for users. When the load on a three-phase distribution transformer is too heavy, selecting an appropriate branch line to install a single-phase distribution transformer based on the load characteristics can cut off and transfer the load, solving the capacity expansion problem. Installing a single-phase distribution transformer to supply power to residents in residential areas without three-phase users can shorten the low-voltage power supply radius and reduce losses. Installing a single-phase distribution transformer to supply power in areas with low load density, wide distribution, and no three-phase users can save investment and solve the power supply point problem. Application Examples Example 1: In accordance with the provincial company's guidelines on promoting the application of single-phase distribution transformers according to local conditions, after thorough research, investigation, and demonstration, we selected a resettlement community in Chengnan with 4 buildings, 16 units, and 160 households as a pilot project. The community was originally powered by one S7-315/10 three-phase distribution transformer with an average low-voltage power supply radius of 280 m. Now, it has been replaced by eight 50 kVA (each powering two units and 20 households) suspended single-phase distribution transformers, with an average low-voltage power supply radius of 12 m. Example 2: Meiyuan Residential Area was a resettlement community built in 1997. The community has one flour processing plant and two small welding shops using three-phase electricity, and approximately 200 households in 32 two-story residential buildings using single-phase electricity. Originally, it was powered by a single S9-320/10 public transformer. In the summer of 2005, residents reported low voltage at the end of the line, and load measurements showed the transformer was at full capacity. We switched from the original transformer to power the three-phase users and 16 buildings near it, and installed four new 50 kVA single-phase transformers at the end of the original low-voltage line, distributed around the original transformer, to power the remaining 16 buildings. This not only solved the voltage quality problem but also reduced low-voltage losses due to the shortened power supply radius. The overall benefit analysis shows a significant reduction in no-load losses for the same capacity. For example, a 50 kVA single-phase distribution transformer has a no-load loss of 135 W, while an S9 series three-phase distribution transformer of the same capacity has a no-load loss of 170 W, a difference of 35 W. Based on 8000 hours of operation per year, the single-phase distribution transformer loses 280 kWh less electricity than the S9 series three-phase distribution transformer. Low-voltage line losses are significantly reduced. The power supply radius of a single-phase distribution transformer is only 10-15 m, which is much shorter than that of a three-phase distribution transformer, resulting in a significant reduction in low-voltage line losses. After meter reading and statistics, the low-voltage line loss rate in the pilot community decreased from 7.61% to 2.72%, saving 1810 kWh of electricity per month. Voltage qualification rate is significantly improved. Due to the greatly shortened low-voltage power supply radius and lower line voltage loss, the voltage qualification rate to households is significantly improved. The reliability of power supply to users is improved. A single-phase distribution transformer supplies power to only 10-20 households. When a single-phase transformer fails, the number of affected households is significantly reduced, and the reliability of the power supply is greatly improved. With a single-phase distribution transformer, high-voltage lines can be installed with two wires, and low-voltage lines with two or three wires, whereas with a three-phase distribution transformer, high-voltage lines must be installed with three wires, and low-voltage lines with four wires. In terms of engineering costs, using a single-phase distribution transformer to supply power to high and low voltage lines can save 1/5 of the construction cost. Regarding the construction cost of the transformer substation, building an H-type distribution substation requires approximately 6,000 yuan in materials, while a single-phase distribution transformer using a single-pole suspension system costs less than 2,000 yuan. Therefore, the cost of the substation can be reduced by 2/3. Application Prospects: Since 2010, single-phase distribution transformers have been widely installed in Suqian City. This widespread adoption is due to the significant social and economic benefits this power supply model has brought to the power distribution network transformation, gaining widespread social recognition. As is well known, low-voltage network losses account for a smaller proportion of power grid losses abroad, the opposite of the current situation in my country. This is because the average household electricity consumption is much higher abroad, with almost every household or even several households having their own dedicated single-phase distribution transformer, and the low-voltage lines being primarily indoors. It is evident that low-voltage distribution networks abroad consistently employ a power supply method characterized by small capacity, dense distribution points, short radii, and direct power to the home. Therefore, we believe that, considering the load density and distribution of my country's distribution network, adopting a single-phase distribution transformer power supply mode will significantly reduce grid losses, making it the preferred solution for power grid construction and an inevitable requirement for building a resource-saving society in my country.