A fuel cell system includes a fuel cell configured to produce electrical power by a chemical reaction of a flow of fuel and a flow of oxygen or air with an electrolyte and a cooling system configured to remove thermal energy from the fuel cell via a flow of coolant through the fuel cell. The fuel cell system includes one or more conductivity sensors configured to measure a change in conductivity of the coolant flow. A method of operating a fuel cell system includes producing electrical power at a fuel cell by a chemical reaction of a flow of fuel and a flow of air with an electrolyte, urging a flow of coolant through the fuel cell to remove thermal energy and ions from the fuel cell, and measuring a conductivity of the flow of coolant via one or more conductivity sensors.

A control method and system of a fuel cell electric vehicle stack. The control method comprises obtaining insulation resistance of the stack, comprising at least two sub-stacks connected in parallel; and disconnecting a sub-stack with insulation failure from a DC bus and then causing the stack to enter a failure mode when it is determined that the insulation resistance of the stack is smaller than a first preset threshold. The stack is determined to have an insulation failure when it is determined that the insulation resistance of the stack is smaller than the first preset threshold. The sub-stack with the insulation failure is located and disconnected the sub-stack with insulation failure from a DC bus, and the stack is then caused to run in a failure mode to perform failure protection, avoid deterioration of the insulation failure and burnout of the stack and improve the safety performance of the stack.

The present invention provides a fuel cell stack protection method, a fuel cell stack protection device and a fuel cell power supply system. The method comprises: determining whether a load-dump failure occurs to the fuel cell; controlling the bleeder circuit connected to the output ends of a DC-DC circuit in the fuel cell so as to discharge the DC-DC circuit when a load-dump failure occurs to the fuel cell. When a load-dump failure occurs to the fuel cell, the bleeder circuit connected to the output ends of the DC-DC circuit in the fuel cell is turned on to discharge the DC-DC circuit so that the DC-DC circuit in the fuel cell can continue to output a current, thus preventing the voltage of a fuel cell stack from rising abruptly because of a load-dump failure and preventing any damage caused by a load-dump failure to the fuel cell stack

The invention relates to a control device (10) for a fuel cell stack (14), the control device being set up to actuate the fuel cell stack (14) using a predetermined current (I.sub.V) and to measure the resulting voltage (U) and to compare this with a reference voltage (U.sub.R). The predetermined current (I.sub.V) depends on the reference voltage (U.sub.R) by means of a sum of at least two exponential functions whose argument in each case contains the reference voltage (U.sub.R). The control device (10) is designed to ascertain the reference voltage (U.sub.R) by approximately reversing the correlation between the predetermined current and the reference voltage (U.sub.R) using an iterative approximation algorithm.

To provide a method for inspecting a gas leak from a fuel cell stack, whereby a leak position can be efficiently identified in a short time. A method for inspecting a gas leak from a fuel cell stack includes a jig installation step of installing a division jig that covers an outer surface, on which stacked end faces of the fuel cell stack are exposed, that divides the outer surface into a plurality of regions, and that includes a plurality of inspection spaces on each divided region. The method further includes a first leak inspection step of identifying a leak region, in which the gas leak occurs, with a gas sensor arranged in each of the inspection spaces.

A fuel cell ship includes a fuel cell compartment in which a fuel cell is installed, a tank compartment in which a fuel tank is installed, a fuel supply pipe through which fuel is supplied from the fuel tank to the fuel cell, and a control unit. The fuel supply pipe includes at least two shutoff valves. Fuel gas detectors that detect a fuel gas being in a gaseous state of the fuel are each installed in the compartments. If at least one of the fuel gas detectors detects that a concentration of the fuel gas is equal to or greater than a predetermined standard value, the control unit controls to close a shutoff valve in a compartment out of the tank compartment and the fuel cell compartment, where the fuel gas detector having detected the concentration equal to or greater than the standard value is installed.

A fuel cell ship includes a propulsion device that generates propulsive force on a hull by electric power, an electric power supply unit that supplies the electric power to the propulsion device, and a degradation rate control unit that adjusts a degradation rate. The electric power supply unit includes a plurality of fuel cells that generate electric power by an electrochemical reaction of fuel and at least one storage battery.

A distributed fault management system includes at least one sensor associated with a fuel cell system and at least one first fault management computing device coupled to the at least one sensor. The at least one first fault management computing device is configured to receive data associated with a first fault condition. The at least one first fault management computing device is further configured to generate a resolution to the first fault condition and transmit at least one resolution command signal to at least one second fault management computing device. The at least one resolution command signal configures the at least one second fault management computing device to use the resolution to resolve a second fault condition in a similar manner.

A method for operating a fuel cell system is provided. The method includes controlling a provision of fuel to the fuel cell system operating in a steady-state mode. The catalyst sensor is operated by providing a portion of the fuel and anode exhaust generated by the system to the catalyst sensor. Further, a change in an outlet temperature of the catalyst sensor is detected. Thereafter, it is determined whether a reformation catalyst of the catalyst sensor is poisoned by contaminants in the fuel based on the detected change in the outlet temperature.

An equipment management method comprises a step A of predicting, at an equipment management apparatus, occurrence of a first abnormality which is an abnormality occurred in a fuel cell system and not predicted by the fuel cell system; and a step B of transmitting, at the equipment management apparatus, a message associated with a prediction for the occurrence of the first abnormality when the occurrence of the first abnormality is predicted.