Offset control arrangement and method for controlling voltage values in a fuel cell system

An offset control arrangement for controlling voltage values of a fuel cell system for producing electricity with fuel cells, each fuel cell in the fuel cell system including an anode side, a cathode side and an electrolyte between the anode side and the cathode side, the offset control arrangement and fuel cell system comprising:

• at least one fuel cell array of at least two fuel cells, and at least one load for performing a load function;
• voltage monitoring means for monitoring input voltage of the load to obtain monitoring information;
• a control processor for processing the monitoring information;
• at least one offsetting source in serial connection to the at least one fuel cell array;
• a power level of the offsetting source being substantially low compared to a power level of the fuel cell array, the offsetting source being arranged to perform at least unidirectional shifting of a fuel cell array output voltage to reduce a voltage window apparent to the load based on at least one of the monitoring information and the processed monitoring information;
• and
• means for disconnecting the at least one fuel cell array from the load, when a reason for disconnection is detected in the input voltage monitoring of the load by detecting that the input voltage rises out of a specified bound.