The design of planar busbar as a must part of any present high power converter is particularly fine due to all electromagnetic phenomena which can not be easily predicted with appropriate simulation means. Among the numerous constraints which apply to this component, current sharing between all paralleled components (power IGBT modules and capacitors) and stray inductances responsible of both over-voltages and current unbalance are studied in the paper. Based on a dedicated inductive partial elements modeling the cabling rules are conceived and proposed following an optimization process is presented in order to achieve the optimal busbar design