The application of load models of electric appliances to distribution system analysis

This paper proposes a methodology to apply the load models of key electric appliances in residential area for distribution system analysis. According to the load models, the transformer hourly loading is estimated during simulation iteration by the bus voltage and ambient temperature. A three phase load flow program is then executed to find the feeder daily profile of power consumption and system loss with the transformer hourly loading derived. Besides, the daily power consumption by each type of key appliance can also be solved. To demonstrate the effectiveness of the proposed method, a distribution feeder of Taipower system is selected for computer simulation to find the potential of energy conservation by controlling the feeder service voltage at the substation. Moreover, the load model of air conditioners, which are temperature sensitive appliances, is also considered in the program to find the impact of ambient temperature change to the power consumption of residential distribution feeders. It is concluded that the load models of key electric appliances can provide a useful tool for distribution engineers to enhance the accuracy of system analysis to estimate the operation efficiency of distribution system in a more effective manner