Theoretical Line Loss Calculation System of Low-voltage Distribution Network Based On Three-phrase Dynamic Unbalance

In considering the effect of three-phase unbalance degree upon the low voltage line loss, the dynamic three-phase unbalance coefficient is adopted to improve the computation method for low-voltage line loss based on equal electric resistance method in this paper. With an aim at the most of low-voltage network without collecting the representative daily current data, the three-phase unbalance degree acquisition device is designed in this paper, which adopts a single chip as its master controller. It is connected to the output terminal of transformer to collect and save the real-time three-phase currents for dynamic unbalance degree calculation. A real low-voltage distribution network is used to test the improved computing method, and to compare the results obtained with the traditional computing method. The results from computing examples indicate that this computing system is feasible and has high potential values in engineering applications, with the calculated results nearing to real value of line loss.