TITLE:
Effects of Harmonics on Power Loss in XLPE Cables
AUTHORS:
W. Z. Gandhare, K. D. Patil
KEYWORDS:
Curve Fitting; Non-sinusoidal Power Loss; Per Unit Harmonic Load; Quadratic Polynomial; Sinusoidal Power Loss
JOURNAL NAME:
Energy and Power Engineering,
Vol.5 No.4B,
November
18,
2013
ABSTRACT: Harmonics in power systems is increasingly at high
level. Also, there has been an incredible growth in the use of cross linked
polyethylene (XLPE) cables in distribution systems. Harmonics cause additional power
loss/temperature rise; causing premature failure of cables. Catastrophic
failure of power cables leads to great inconvenience to consumers and loss of
system reliability and money. To avoid the overheating of power cables; the
additional power loss due to harmonics should be accurately calculated and
properly accommodated by derating the cable. The present method of calculating
the power loss in cables in harmonics rich environment is very arduous. The aim
of this paper is to present the reasonably accurate method for evaluating
effects of harmonics on the power loss in XLPE cables. Computational model is
developed in MATLAB for power loss calculation using conventional method. Using
this model, calculations are performed for aluminium and copper conductor XLPE
cables of different size and type; for three different types of harmonics
spectrums having total harmonics distortion (THD) of 30.68%, including all odd
harmonics components up to 49th order. Using these results; a
mathematical model in the form of simple empirical formula is developed by
curve fitting technique. The results obtained by various models are presented
and compared with error justification.