Abstract:
The management of power systems has become more difficult than earlier because power systems are operated closer to security limits, environmental constraints restrict the expansion of transmission network, the need for long distance power transfers has increased and fewer operators are engaged in supervision and operation of power systems. And because the main objective of operating electrical power systems is to serve the energy with acceptable voltage and frequency in addition to, factors of reliability and security of the service all this make these systems during this difficult situation can effect by several and serious problems.
One of serious problems in power systems that can threaten the concept of power systems reliability and security is voltage instability therefore In the recent years, the analysis of voltage stability has assumed importance, mainly due to several documented incidents of voltage collapse In many countries rather in, Sudan national grid.
In this project voltage stability analysis was performed on simplified Sudan national grid to identifying weakest buses in this grid from point view of voltage stability using voltage changing index that is first applied to IEEE 14-bus benchmark to ensure his successes ,then ranking for these buses to arrange her from weakest to strongest was achieved to avoid intensive loading for weakest buses and to solve reactive power problem that has significant effected on voltage in these buses, all this to prevent voltage instability in this grid that is lead directly to total blackout and it’s worst consequence.
