Maximum efficiency of flexible AC transmission systems

The maximum efficiency of a transmission line is a concern from design and operation viewpoints. Today varieties of flexible AC transmission system (FACTS) devices are being included to enhance system stability and to improve power transfer capability. In this paper, the influence of different FACTS devices on maximum efficiency is studied. The equivalent A B C D constants of transmission system, which include different shunt and/or series FACTS devices at different locations of transmission line, are formulated to evaluate the maximum efficiency. Simulations on maximum transmission efficiency are performed for a 500 kV system.