A hybrid numerical method to calculate the sag of composite conductors

A modification to the numerical sag method (NSM) for predicting conductor sag is presented that accurately predicts the observed bilinear sag behavior of composite conductors. The modified method, called the hybrid sag method (HSM), uses the stress–strain curves of conductors to calculate the initial load distribution between the components of the composite conductors. In this study, the HSM is used to predict sag of conductors with conventional designs. The HSM predictions are compared with those obtained using a conventional graphical sag method as well as NSM. The HSM shows superior accuracy over NSM and virtually the same accuracy as the graphical method for predicting sag for composite conductors operated under specific conditions. The HSM predictions of sag are validated by comparisons with experimental measurements.