Investigation and efficiency analysis of a 405 km transmission line with series compensation

This paper presents an investigative case study and energy efficiency analysis of the 405 km, 420 kV transmission line between Insukamini substation in Bulawayo in Zimbabwe and the Matimba thermal power station in South Africa. Three scenarios were evaluated: 1) where a line to ground fault occurred on the secondary bus, 2) where an impedance fault occurred on the two transmission lines and 3) where the combination of the above two faults occurred. An analysis was made on the energy efficiency of the load with respect to the three scenarios by means of a simulation model. The development of the simulation model for this specific case study is explained in detail. The simulation model was slightly adapted in order to simulated series compensation on the network. From the results obtained from the simulation model it can be seen that the energy efficiency decreases for all three scenarios. Part of this paper provides an overview of transmission line theory and series compensation theory.