The effects of normalization of static load characteristics

This paper presents the results of parameter identification of static load characteristics on the basis of large number of field tests. The parameters of most frequently used, polynomial and exponential load model are determined using two different ways of normalization — normalization with voltage and power values just before the voltage change, and normalization with rated voltage and power values. Significant differences between corresponding identified parameter values and predicted power values are found depending on the way of normalization. Better characteristics of normalization with rated voltage and power values are emphasized. This normalization is suggested for power system analyses because another way of normalization causes large parameter deviations and big mistakes in prediction of load values in the examined voltage range, from 0.95 to 1.1p.u.