Loadability Assessment of 330 kv Network for Contingency Expansion Planning for Improved Reliable Power Supply

Abstract

The selections of line to be switched depends on system overload, this means that elimination of overloaded lines are key parameter for loadability assessment,. Load flow analysis shows that Nigeria power system classified and ranked as one of the unstable system. Since operating limit are based on certain criteria for voltage stability rating, transient stability rating, system voltage limit, power flow limit which must comply to statutory conditions in order to avoid system collapse. There are many ways in which system can be adjusted to compensate for an overloaded line. Previous researchers has shown that shift in generation or phase shifter adjustment can be calculated to correct an overload, these corrections are based on analytical solutions of the systems, however, many algorithms has been developed to use these techniques for load flow solutions. Evidently, effort has been made through PHEDC, PHCN, NERC, private and public practitioners and system planners and operators on the view to improve its reliability through co-existence expansion program.

This paper will adopt the application of Newton-Raphson load flow, impedance matrices techniques embedded in power world simulator software tool on the view to address contingency due to system loadability margin to access any form of violations that may result to system outages or failure. Single-line representation of the study case (Afam to Alaoji, Benin to Onitsha, Sapele to Benin and Onitsha to Alaoji) were characterized and represented .Selection of lines to be switched are proposed to be doubling the line overload for purpose of reinforcing for power quality and voltage profile. Essentially, the technique have the capacity to develop, identify overloaded lines to be removed in order to reduce the line overload in the power system, this means that line can be added or removed from the system on the view to cause a shift in the power flow in order to avoid network congestion.