This paper proposes the application of advanced modelling and control strategies for a single phase Dual Active Bridge (DAB) based Medium Voltage DC (MVDC) Shipboard Power System (SPS). In these systems the tightly controlled point of load (POL) converters exhibit a constant power load (CPL) behaviour, which has a destabilising effect on the bus voltage. In this work, a Multiple Input Single Output (MISO) state space plant model based on switching function for the triple phase shift (TPS) modulated DAB converter is derived. For obtaining the MISO model the generalised state space averaging (GSSA) technique was used. A H∞ mixed sensitivity controller is designed to tackle the negative impedance characteristics of tightly regulated Point of Load (POL) converters, presence of measurement uncertainty and high current stress. This paper also presents a detailed description of the design of weighting functions required for the mixed sensitivity formalism. The effectiveness of the proposed modelling scheme and control strategy is studied through system level simulations. A comparative study with the previously proposed TPS control strategy is performed.