Presenting a new correction factor for IEC 60364-5-52 Standard in cable calculations under harmonic conditions

Abstract

The increasing expansion of nonlinear loads is considered a serious challenge for distribution companies. In this study, Golestan commercial complex in Baneh City has been evaluated in terms of power quality. There are about 6000 compact fluorescent lamps (CFLs), 400 PCs and laptops in this complex. Imposing such a large number of nonlinear loads on this feeder led to a total harmonic distortion current (THDi) of 57% and a total harmonic distortion voltage (THDv) of 8.5%. Such high loads on the distribution feeders result in high harmonic pollution in the grid, raising the need for revising the design of distribution grids. In this study, a power quality analyzer device was installed on the supply feeders of Golestan commercial complex through which all the power quality parameters were extracted. Then, a new method was presented to determine the cross-section of the distribution cables in harmonic conditions and it was compared with the traditional methods. Moreover, the problem in IEC 60364-5-52 standard regarding the correction factor related to the third harmonic value for determining the cable size was investigated and an appropriate correction factor was presented to solve this problem.