An Efficient Method For Computing Loss Formula Coefficients Based Upon The Method of Least Squares

Abstract

Presented in this paper is a method for efficiently computing the Loss Formula Coefficients. These Coefficients are derived in a straightforward manner quite different from the complicated approach of reference frame transformations based upon Kron's tensor analysis. Linear nonconforming loads and linear generator reactive/real power output relationships are approximated quite successfully using the technique of least squares fitting. These linear relationships provide the basis for a simplified derivation of the Loss Formula Coefficients in full quadratic form. The perplexing problem of undefined ΔΔ/ΔP ratios for generator axis buses is circumvented in this procedure. In addition, the necessity for defining additional axis buses to accomodate constant loads is avoided. Two or more load flow cases representing various load levels of a given system provide the sample points necessary for approximating the linear relationships by least squares fitting.