Minimization of corona power loss in transmission line:- Nnubuogu, Nonso F.

ABSTRACT

Electric power transmission practically deals with the bulk transfer of electrical energy from that carried at the sending end. Efforts must be made to reduce these losses and increase transmission efficiency which will increase profitability in electricity business. Many losses exist in power transmission lines; but this research will concentrate on only corona losses and ways of reducing or minimizing it since it is almost impossible to eradicate it. Research has also proven that increasing the spacing of the three phase in power transmission lines reduce the effect of corona. However, increasing the spacing increases the line inductance and hence the reactive power loss along the line which may cause low voltage (or voltage instability) at load centers. This research will find the exact spacing between conductors ofthe three phases with which the inductance caused by the spacing will satisfy recognized standard using graphical method of analyzed. From the analysis, using 150mm2 size of cable in transmitting 7.5MVA, a conductor spacing of 87cm was found to be the best with corona loss of 2.80kVA/km and a corresponding reactive power loss of 5.28kVA/km. Further increase in conductor spacing will although reduce corona loss; the corresponding reactive power loss will be beyond the acceptable limit.