Determination of customer load characteristics by load survey system at Taipower

This paper proposes a load survey system to determine the load characteristics of various customer classes in an electric utility company. The questionnaires are adopted to find the power consumption of key electric appliances. The actual power consumption of hundreds of customers are collected by intelligent meters. Sampling theory has been applied to find the proper sample size of both questionnaires and field tests so that the customer load characteristics will be derived with sufficient confidence level. Statistical analysis is then performed to find the power consumption model of each customer class based on the power measurement of field tests. The temperature effect on the power consumption of each customer class is also investigated by differentiating the proposed power consumption model with respect to the ambient temperature. The proposed method has been adopted by the Taipower company to better understand the customer load characteristics to support various functions of power system planning and operation in a more effective manner.