农村电网合理配电方式的优化选择

为降低农村电网的投资和运行费用,在满足负荷需求及各项技术指标限制的条件下,以线路电压降和变电站最大负荷限制为控制条件,建立各种配电方式的单位供电面积年费用与线路供电半径、变电站数量、负荷密度等因素之间的函数关系,对我国农村电网3种配电方式110/35/10kV、110/20kV、110/10kV的经济性进行研究和比较。结果表明:当负荷密度低于250kW/km2时,110/10kV配电方式的单位供电面积年费用相对较低,而负荷密度高于250kW/km2时,110/20kV的配电方式则更经济;而110/35/10kV配电方式因为使用广泛且经济性与另外2种配电方式接近,仍有很高的保留价值。

Research of reasonable distribution modes of rural power grids

In order to reduce the investment and operating costs of rural power grid,we developed a model to describe the effects of annual cost of unit supply area on the radius of line power supply,the number of substations and the density of load,by using the line voltage drop and the maximum load limit as control conditions,under the demand of load and the limits of technical indices.The comparisons of economies of three modes of power distribution of China’s rural power grid,110/35/10 kV,110/20 kV and 110/10 kV,were performed by the approach above.The results show that when the load density is below 250 kW/km2,the annual cost of 110/10 kV distribution mode is the lowest;when the load density is greater than 250 kW/km2,110/20 kV distribution is the most economical;and for 110/35/10 kV distribution mode,there is still high value to preserve it due to its wildly use and the similar cost to the other two distribution modes.