Design Of Single-Phase Power Supply System In Urban And Rural Distribution Grid

With the development of construction of distribution smart grid and upgrade of urban and rural power grid in our country, single-phase power distribution technology has been paid more and more attention, and the State Grid Corporation is active in application and research of the single-phase power supply grid. With the advantages of "small capacity, dense distribution and short radius", the single-phase power supply can reduce the line loss, improve power supply reliability and voltage quality significantly, and meet the multi-level demand for power supply in urban and rural power grid. It has great significance for the centralized residential area and the other areas with single-phase load dense. Single-phase distribution technology has been identified as one of the key technologies of energy saving, loss reduction and improving of the power supply’s reliability. For the application of single-phase distribution technology in regulation, and the guarantee of power supply of single-phase power supply system’s reliability, many issues related with the single-phase power supply system have become the pressing research topics.The beginning chapter of the thesis researches the single-phase power supply’s operation principle and superiority, and analyzes the single-phase power supply system’s impacting on the unbalance of three-phase load, the reliability of power supply, the power loss, the power supply quality and other aspects.Combined with the situation of urban and rural distribution network in our country, the next chapter analyzes the regional and load characteristics, and gives typical power supply area classification of the single-phase power supply system. Based on using the distribution network planning theory, standard codes and optimized combination of power system elements scientifically, the chapter designs typical power supply modes of single-phase power supply system, which are applicable to the different load conditions and economic development level. The models contain the middle-voltage and low-voltage access modes, the typical configuration of power supply unit and power supply equipment and the single-phase distribution transformer selection scheme.In order to ensure the stable and reliable operation of the power supply system, the following chapter introduces the applicable and economical design proposal of fault location and transformer operation monitoring system of single-phase distribution grid, and research the application of the system in overhead line system and cable line system.Combined with the actual project and using the typical power supply modes of single-phase power supply system introduced in this thesis, the last chapter gives the typical design scheme of the single-phase power supply system, including middle-voltage and low-voltage access modes access mode, design of grounding system, fault location and transformer operation monitoring system of single-phase distribution grid, especially the design of the10kV single-phase pole-mounted transformer district, a new single-phase distribution transformer monitoring and measuring device and a new10kV single-phase prefabricated transformer substation. The result verifies that the design scheme of single-phase power supply system can be effectively applied to our country urban and rural distribution grid, and able to provide a reference for single-phase power supply system’s reconstruction in old residential areas and implementation in new residential areas.