Variable DC Approach in Fuel cell And Battery Powered Marine Power Systems: Control of The Fuel Cell Power Converter

Previously, the Variable DC approach concept was proposed for operation of hybrid fuel cell and battery powered marine vessels. The concept was shown to provide significant efficiency improvement, and consequently improved hydrogen fuel savings. However, although the general concept and the control of battery DC/DC converter has been detailly described in previous works, the operation of fuel cell DC/DC converter in different Variable DC approach control modes has not been presented. This paper proposes a fuel cell DC/DC converter control system specifically designed for operation in the three Variable DC approach control modes. The functionality of the proposed fuel cell DC/DC converter and the Variable DC approach in general is verified using a hardware-in-loop test setup consisting of virtual power stage models and real converter controllers. The system is shown to function well in both normal operating conditions and various fault conditions.