Investigation of harmonic of 3 - phase controlled rectifiers and electromagnetic forces acting on adjacent busbars due to these currents / Mona Mohamed Mahmoud Abd El Aziz , supervised EssamElDin Mohamed AbouElZahab , amr Amin Mohamed Adly , Hisham Alsaid Amin ElKhashab

Thesis (M.Sc.) - Cairo University - Faculty Of Engineering - Department Of Electrical Power and Machines

The power system busbar structure design has always been an important issue in the electric power utility designUnder normal operation , the busbars are subjected to very small electromagnetic forces , but during short circuit faults , very high instantaneous electromagnetic forces are applied to the busbarsAlso , these forces will have considerable values in the presence of distorted harmonic currents resulting from non - linear loads such as rectifiers These electromagnetic forces may cause deformation in the busbars , rupture of the insulating supports and excess vibrational stresses on the busbarsThus , forces must be computed in order to suggest the best busbar structure and inter - spacing between adjacent busbars in order to withstand these forces This thesis introduces an analytical approach to compute local force density in every busbar section and the overall forces per unit length for every busbar An assessment of the overall forces on various busbar structures is made considering all the factors affecting these forcesThese factors are the busbars dimension , the instantaneous current values that determine the busbar carrying the maximum current value , inter - busbar spacing , the vicinity of metal conducting plate and the busbar arrangements , either the cross sectional area , in which the current density flow perpendicular to the surface , is horizontal or vertical arrangement but in all cases it is laid horizontally The local force density and overall force computation is made in case of steady state current neglecting harmonics , steady state current considering harmonics and in case of short circuit current An experimental model of 3 - pulse rectifier is implemented to investigate the local force density in the presence of harmonic currents over one cycle

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