Modelling of shipboard medium-voltage direct current system for system level dynamic analysis

Medium-voltage direct current (MVDC) power system has been considered the trending technology for future all-electric ships to produce, convert and distribute electrical power with improved connectivity, reliability and power quality. However, with the substantial employment of high-frequency power electronics converters in the MVDC system, the corresponding analysis of system stability and especially the accurate assessment of system dynamic behaviours following disturbances have become serious concerns for system studies and control designs. In this study, an analytical time-domain modelling methodology that leverages average-value modelling techniques is developed for MVDC shipboard power system to facilitate the system-level transient analysis. The accuracy of the proposed approach is verified by comparing the simulation results to the equivalent Simulink benchmarks. In contrast with the high-fidelity model and the conventional modelling approach which only captures the steady-state characteristics of the system, the proposed method is proven to be effectively and accurately simulate the system behaviour during the transient phase with enough details to verify and refine related system-level dynamic analysis and control design.