Robust Passivity-Based Control for Interleaved Bidirectional DC-DC Power Converter With Constant Power Loads in DC Shipboard Microgrid

With the use of interleaved bidirectional dc-dc power converter (IBDPC) in dc shipboard microgrids (SMGs), the power can be delivered efficiently between the set of batteries and the dc bus during charging and discharging modes. The constant power loads (CPLs) dynamics of the propulsion motors control systems and hotel loads in dc SMGs are the prime cause of the dc bus voltage instability. Besides, the torque changes due to the operating nature of ships on the sea is also a problem. Therefore, robust dc bus voltage control is a crucial matter. This article presents a robust passivity-based control (PBC) strategy to stabilize and control the dc bus voltage and eliminate the steady-state error caused by the CPL changes. To this end, the nonlinear disturbance observer (NDO) is added to enhance system stability and to improve the control robustness of the PBC strategy. The proposed method ensures large-signal stability, fast recovery performance, and global trajectory tracking to the reference dc bus voltage. MATLAB/Simulink and experiment results have been presented to verify the control performance.