Objective According to the characteristics of the complex waterways of inland rivers, a DC grid solution based on a multi-energy parallel hybrid green intelligent bulk carrier is proposed.

Methods The advantages of a DC grid for hybrid power are analyzed and the DC grid propulsion efficiencies of each typical working condition for hybrid power are obtained through power chain calculation. The design characteristics of the DC grid are researched according to the specific requirements for the additional signs of green intelligent ships. The DC power system design schemes focused on protection and safety for real ships are then analyzed.

Results The results show that the comprehensive performance of the DC grid propulsion system for multi-energy parallel diesel-electric/gas-electric hybrid ships is superior to that of main engine propulsion systems and full electric propulsion systems. The multi-equipment protection mode and blackout recovery solution can ensure the safe application of the DC grid.

Conclusions The DC grid can build a flexible energy platform for the highest level of green inland river ships, and provide comprehensive support for the intelligent engine room, intelligent energy efficiency and intelligent integrated platform technology and its applications. The results of this study can provide valuable references for other green intelligent hybrid ships.