(1. School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China; 2. State Grid Xuji Group Corporation, Xuchang 461000, China)

The insufficiency of power supply capability for 10 kV power distribution network(PDN)can be solved by employing 20 kV AC voltage level or adopting DC power distribution technology on existing transmission lines. While for each scheme there are different characteristics and applicable conditions. The paper mainly focuses on the comparison of different PDN reform and upgrading schemes. Firstly, ±10 kV and ±15 kV are selected as the DC voltage levels to be studied according to the relative electrical insulation coordination conditions. Then, the power supply capabilities and operation efficiency changes with the total load, power supply radius, medium voltage DC load and distributed generator connection power variation conditions for 10 kV AC, 20 kV AC, ±10 kV DC and ±15 kV DC power distribution schemes are analyzed and compared by a typical radial topology example case. Preliminary economy analysis has also been carried out on these four schemes.