In this paper, modular IPT systems which have receiver series/parallel compensation with series/parallel common DC-Bus are investigated. For these systems, power sharing between the receiver modules is vulnerable to system components such as the mutual coupling between the transmitter and the receiver coils. It is also observed that the power sharing is affected by the compensation topologies of the receivers and the type of the electrical connection of common DC-Bus. Therefore, in this study, a mathematical model is presented to reveal the power sharing characteristics in terms of operating frequency and mutual inductance differences of the modules. Then the mathematical model is verified for series compensated, series/parallel connected IPT systems with single transmitter-two receivers, and 5% mean error is achieved.