建立了220/20kV序列的电网模型,推导了变电站投资、网损费用及电网投资年费用关系式。引入精神磨损理论分析113序列电网的隐形价值流失,通过比较新、旧电网年费用可制定合理的电网改造投资决策。分析了新建区域和旧网改造情况下220/110/10、220/110/20、220/20kV3个电压序列的技术经济性,建议新建区域考虑采用220/20kV电压序列供电,投运时间超过15a且负荷密度大于33MW/km2时,将原电网220/110/10kV电压序列改造为220/20kV电压序列能取得良好的经济效益。
A mathematical model for distribution network adopting 220/20 kV voltage series is built; and relational expression of substation investment, network loss cost and annual cost of network investment is derived. The spirit-wear theory is led in to analyze the invisible value run-off on distribution network adopting old voltage series. By means of comparing the annual cost of power network adopting new and old voltage series, the rational investment decision-making for distribution network renovation can be drawn up. The techno-economies of three voltage series, namely 220/110/10 kV, 220/110/20 kV and 220/20 kV, adopted for newly built distribution network and for the renovation existing distribution network are anlayzed, thus it is suggested that the 220/20 kV voltage series should be applied to the power supply for newly built areas; for existing distribution nework, when its being operated period is longer than 15 years and the its load density is higher than 33 MW/km2, it is suitable to renovate the existing distribution network from adopting old voltage series 220/110/10kV to adopting 220/20kV voltage sereis and satisfied economic benefit can be attained.