A high reliability vessel is provided with redundancy zones, and an improved system for a high reliability vessel that overcomes complexities in the prior art and solves the problem of improved reliability. The vessel comprises a plurality of redundancy zones, a thruster system comprising at least two thrusters to create transversal thrust, and a main power supply system comprising a generator system, and a main electrical distribution system comprising a switchboard system. The vessel further comprises an energy storage system comprising a plurality of energy storage subsystems, wherein at least one of the thrusters with an operatively connected energy storage subsystem is located in a first redundancy zone, and another of the thrusters and the generator system is located outside the first redundancy zone.

A DC power distribution system has power sources, a DC power distribution bus with DC bus sections. The system has power switching assemblies to couple one of the DC bus sections to another and a system controller. An inverter is connected to one of the power switching assemblies to supply a consumer. The first and second terminals are electrically coupled to first and second bus sections. First and second semiconductor devices between the terminals control current flow and there is a current connection from each terminal to a power switching assembly controller for providing an indication of current. A control signal line is connected between the power switching assembly controller and each semiconductor device provides a signal to the semiconductor devices to control the current flow and an inverter coupler couples each current connection to the inverter. The inverter coupler has a feed from each current connection to the inverter.

An engine device executes the control of the opening degree of a main throttle valve when engine load is in a low load area. In contrast, when the engine load is in a medium-to-high load area, the engine device sets the main throttle valve to a predetermined opening degree and executes the control of the opening degree of an air supply bypass valve.

The present invention provides a marine propulsion system that is suitable for any civilian and military marine vessels and which offers operational flexibility. The marine propulsion system includes a pair of ac busbars, each in parallel connection with a power converter. The respective power converters each connected in parallel to a propulsion motor.