This paper discusses the analytical modeling of the input current absorbed by an Inductive Power Transfer System (IPTS) operating under dynamic conditions. The input current model is needed to consider the total current delivered by the source and investigate the distribution of the currents through the bus connection of the inverters of each transmitter stage, in order to assess the influence of vehicles number, distance, speed and trajectories when transiting over the charging spots. A real-world 85 kHz / 11 kW dynamic battery-charging IPTS is adopted as a reference case study to validate the proposed analytical model.