引入三相不平衡度的低压电网理论线损计算

Theoretical line loss calculation with three-phase unbalance degree for low-voltage distribution network

提出采用均方根电流法计算低压电网理论线损,通过分析三相不平衡线路的线损,推导出线损与不平衡度的关系公式,并将该公式用于三相不平衡配电线路的理论线损计算。系统引入三相不平衡度采集装置,以单片机为主控制芯片,给出了系统结构框图。在采集三相电流时,使用该采集装置挂接在变压器出口端,定时实时采集和存储三相电流,以供计算三相不平衡度。以某台区实际运行为研究实例,介绍了计算步骤,计算结果表明所提出的计算系统是可行的。

The mean-square-root current method is proposed to calculate the theoretical line loss for low-voltage distribution network. Based on the analysis of three-phase unbalanced line loss,the relationship between line loss and unbalance degree is deduced,which is then applied to theoretical line loss calculation for unbalanced three- phase distribution network. The three- phase unbalance degree acquisition unit is designed,which is connected to the output terminal of transformer to collect and save the real- time three-phase currents for unbalance degree calculation. With a singlechip as its master controller,its system structure is presented. For a real distribution network,the calculation steps are introduced and the calculative results prove its feasibility.