Reliability Modeling of Multiple Overhead Transmission Lines

An improved model is suggested for analyzing the reliability of two transmission lines on the same tower. The model accounts realistically for tower failures. A line model is developed for the case when no facilities exist for repairing a single line during the operation of the other line. This situation is encountered in practice due to shortages of personnel and/or equipment. Approximate expressions for failure frequency and probability of the lines in both unrestricted and restricted repair are suggested and their validity is checked in some examples.