Disturbance analysis in conversion of double three-phase to six-phase transmission network

Fault occurrence in power systems could result in losing their stability and cause severe damages in faulted devices or adjacent healthy devices. Also, stability proposition is charged as an important component in energy management and planning of power systems. Moreover, during the motor starting period, it draws a large current from the system, results in voltage drop of system and poses disturbances to the normal operation of other loads. Hence, fault and induction motor starting analysis are important studies in design and development of power systems. Beside, conversion of 3-phase double-circuit (3PDC) to 6-phase single-circuit (6PSC) line is a well known method to increase the power transfer capability of the network. So in this paper, an investigation of fault occurrence and motor starting for 3PDC converted to 6PSC transmission line is studied. According to the achieved results, if network is converted to 6PSC network, then system performance from view of transient stability and motor starting could improve, but magnitude of fault current may be increased than the 3PDC network. In this study, power system is assumed as a balanced system. Other economical and practical factors can be studied for planning, development and design of future transmission networks.