A disclosed fuel cell system includes a fuel inlet that receives a fuel gas from a fuel source, a gas analyzer that determines a composition of the fuel gas received by the fuel inlet, and a stack including fuel cells that generate electricity using the fuel gas received from the fuel source. The fuel cell system further includes a controller that controls at least one of a fuel utilization of the stack, a current generated by the stack, or a voltage generated by the stack, based on the composition of the primary fuel gas determined by the gas analyzer. The controller may control the fuel cell system by increasing or decreasing a fuel flow rate to thereby increase or decrease the voltage generated by the stack to maintain a predetermined target voltage or to maintain a predetermined rate at which usable fuel is supplied to the stack based on composition.

A stack current controller may be configured to determine a stack current request based on a state of charge of a battery, an error based on a difference between an actual coolant temperature and a coolant temperature setpoint, or both. A plurality of stack current levels may be implemented corresponding to different battery state-of-charge thresholds. The determined stack current magnitude may be the lowest current magnitude that provides sufficient heat to maintain a coolant temperature at the coolant temperature setpoint or within the coolant temperature threshold. The determined stack current magnitude may be the highest current magnitude that provides sufficient power while maintaining a coolant temperature at the coolant temperature setpoint or within the coolant temperature threshold.

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.

A fuel cell vehicle is mounted with a fuel cell system including a fuel cell stack and a battery. The fuel cell vehicle controls operation of the fuel cell system with an ECU, to perform standby power generation from activation to when travel is allowed and to perform power generation during operation of the fuel cell vehicle after travel has been allowed. In an activation method, the power generation current is increased in accordance with a low-temperature efficiency rate during the power generation during operation, the battery is charged and the power generation current is increased in accordance with a standby current increase rate that is lower than the low-temperature efficiency rate during the standby power generation.

A fuel cell system wherein the fuel cell comprises an electrolyte membrane; wherein the electrolyte membrane is a perfluorosulfonic acid (PFSA) membrane; wherein the controller has a data group showing a correlation between the current of the fuel cell and the temperature of the fuel cell which is necessary to keep a moisture content of the electrolyte membrane at a predetermined moisture content threshold or more; and wherein, when the temperature and voltage of the fuel cell become a predetermined first temperature threshold or more and a predetermined voltage threshold or more, respectively, the controller conducts a temperature dropping time power generation mode in which power generation is conducted while controlling the current of the fuel cell with reference to the data group, until the temperature of the fuel cell becomes a predetermined second temperature threshold which is lower than the first temperature threshold.

The present disclosure generally relates to systems and methods for fuel cell regeneration after degradation.

An engine assembly includes a combustor, a fuel cell stack fluidly connected to the combustor, the fuel cell stack being configured (i) to generate power using fuel and air directed into the fuel cell stack and (ii) to direct fuel and air exhaust from the fuel cell stack into the combustor, a compressor fluidly connected upstream of (i) the combustor and (ii) the fuel cell stack, the compressor being configured to generate compressed air to direct into the fuel cell stack, a turbine disposed downstream from the combustor, the turbine having a turbine inlet temperature, and a controller that is configured to control a power allocation between the fuel cell stack and the turbine based upon the turbine inlet temperature of the turbine. The combustor is configured to combust the fuel and air exhaust from the fuel cell stack into one or more gaseous combustion products that power the turbine.

A fuel cell system includes a fuel cell stack in which a plurality of unit cells is stacked, a detection unit configured to detect a cell voltage of at least one of the unit cells, a converter configured to regulate an output current of the fuel cell stack, and a control device configured to control the converter. The control device executes current reduction processing for reducing the output current in a stepwise manner when the cell voltage detected by the detection unit is a negative voltage.

The present disclosure relates to a control method for a fuel cell. The control method includes: collecting, by a controller, state information of a fuel cell (FC) stack; determining, by the controller, a degradation state of the FC stack from the collected state information of the FC stack; correcting, by the controller, a basic threshold output corresponding to a present driving state of a vehicle on the basis of information of the determined degradation state of the FC stack; comparing, by the controller, a post-correction threshold output that is obtained by correcting the basic threshold output and a motor demand output, and determining, by the controller, stopping or restarting of a fuel cell; and controlling, by the controller, such that the determined stopping or restarting state of the fuel cell is achieved.

A heater is described. The heater includes a fuel cell to produce heated air, electricity and water vapor. The heater further includes a heating element operatively coupled to the fuel cell to convert the electricity to heat and a control system operatively coupled to the fuel cell and the heating element, the control system being configured to monitor and control the fuel cell and heating element.