Cost related optimum design method for overhead high voltage transmission lines

The design of transmission lines is often the key issue for the existence or absence of failures caused by lightning. Detailed engineering studies are usually performed by electric power utilities for the design of new transmission lines. However, there are also cases where the design is based simply on tradition or on utilities' standardization policy. The paper presents a cost related method for the optimum design of overhead high voltage transmission lines, which intends to reduce or even eliminate the lightning failures. Lightning failures' cost is related to design parameters' cost in order to calculate the optimum and most economic design parameter values. In order to validate the effectiveness of the proposed method, the method is applied on several operating Hellenic transmission lines of 150 and 400 kV, respectively, carefully selected among others, due to their high failure rates during lightning thunderstorms. Special attention has been paid on open loop lines, where a possible failure in them could bring the system out of service causing significant problems. The proposed parameters that occurred by the design method and which reduce the failure rates caused by lightning, are compared with the operating transmission lines' existing design parameters showing the usefulness of the method, which can be proved a valuable tool for the studies of electric power systems designers. Copyright © 2007 John Wiley & Sons, Ltd.