A method for diagnosing at least one fuel cell stack of a fuel cell device by way of a fuel cell diagnostic system includes: impressing a sinusoidal first and at least one sinusoidal second AC current into the fuel cell stack; recording a sinusoidal first and second voltage response of the fuel cell stack; evaluating the first voltage response and evaluating the second voltage response by way of an analytical algorithm for a differential impedance analysis; determining a first resistance, a second resistance and a capacitance of the fuel cell stack by specifying an equivalent circuit diagram for the fuel cell stack; and diagnosing the fuel cell stack on the basis of the determined first resistance, the determined second resistance and the determined capacitance, wherein the diagnosis is carried out in real time. A computer-readable storage medium and a fuel cell diagnostic system are also described.

A fuel cell system comprising: the fuel cell, the secondary cell and a controller, wherein, when a power generation pretreatment of the fuel cell is carried out, and when there is a request from the fuel cell to run the vehicle by output power of the secondary cell, the controller calculates discharge permission energy of the secondary cell, calculates a running permission delay request time from the discharge permission energy, which is a time necessary from the request to run the vehicle to the permission to run the vehicle, and measures a running permission delay time, which is a time that elapsed from the request to run the vehicle, and wherein, when the running permission delay request time value is smaller than the running permission delay time value, the controller permits the vehicle to run.

An incorporated air supplying apparatus for a fuel cell stack and a method for controlling an air flow using the same are described. The apparatus includes an air supply part supplying air to a plurality of fuel cell stacks, a plurality of pipes configured to transmit the air supplied from the air supply part to each of the fuel cell stacks, a flowmeter and a valve installed at each pipe, and a controller controlling an opening degree of each of the valves, based on information on the measured flow. The controller controls the opening degree of the valve installed at each pipe, thus enabling the air flow for each pipe to be controlled.

An incorporated air supplying apparatus for a fuel cell stack and a method for controlling an air flow using the same are described. The apparatus includes an air supply part supplying air to a plurality of fuel cell stacks, a plurality of pipes configured to transmit the air supplied from the air supply part to each of the fuel cell stacks, a flowmeter and a valve installed at each pipe, and a controller controlling an opening degree of each of the valves, based on information on the measured flow. The controller controls the opening degree of the valve installed at each pipe, thus enabling the air flow for each pipe to be controlled.

The invention provides a water tank heating method and unit, an electronic device and a solid oxide fuel cell (SOFC) system. Before the SOFC system is started, ice in a water tank has been heated up, so after the SOFC system is started, the heating time of the heated ice, i.e., the thawing time of the water tank, will be shortened. Further, in the ice heating process, a pre-set needed SOFC thawing time determined according to current stack outlet temperature is used as a heating control parameter. As the stack outlet temperature is a key factor influencing the starting time of the SOFC system, the heating control will be more accurate if the pre-set needed SOFC thawing time corresponding to the stack outlet temperature is used as a heating control parameter.

A method for distinguishing the cause of voltage losses in a fuel cell device includes: a) Detection of a quasi-stationary operation of the fuel cell device, b) Acquisition and storage of a measured current-voltage characteristic curve with the current values and the voltage values of a fuel cells stack of the fuel cell device, c) Use of a PtOx model to determine PtOx voltage losses and calculation of a corrected current-voltage characteristic curve for the PtOx-free and normally humidified fuel cell stack, and d) Comparison of the current-voltage characteristic curves determined in step b) and in step c) and detection of an at least partially dried-out fuel cell stack if the measured current-voltage characteristic curve runs below the corrected current-voltage characteristic curve. A fuel cell device and a motor vehicle comprising a fuel cell device are also provided.

A method for distinguishing the cause of voltage losses in a fuel cell device includes: a) Detection of a quasi-stationary operation of the fuel cell device, b) Acquisition and storage of a measured current-voltage characteristic curve with the current values and the voltage values of a fuel cells stack of the fuel cell device, c) Use of a PtOx model to determine PtOx voltage losses and calculation of a corrected current-voltage characteristic curve for the PtOx-free and normally humidified fuel cell stack, and d) Comparison of the current-voltage characteristic curves determined in step b) and in step c) and detection of an at least partially dried-out fuel cell stack if the measured current-voltage characteristic curve runs below the corrected current-voltage characteristic curve. A fuel cell device and a motor vehicle comprising a fuel cell device are also provided.

Systems and methods configured to receive a set of real-time flight conditions and a user-selected objective function. The user-selected objective function is one of a plurality of objective functions. The systems and methods determine, with an emissions tuning model, one of a plurality of sets of fuel cell operating conditions based on the set of real-time flight conditions and the user-selected objective function. The systems and methods are configured to control a fuel cell assembly operating parameter according to the determined one of the plurality of sets of fuel cell operating conditions.

A system for determining performance of a fuel cell stack may include a vehicle that collects a current of the fuel cell stack and a current of the fuel cell stack and a server that receives the voltage of the fuel cell stack and the current of the fuel cell stack from the vehicle in real time, determines an average state of health (SOH) of the fuel cell stack for each current section within an effective current range based on the current of the fuel cell stack and the voltage of the fuel cell stack within the effective current range, determines an overall average SOH in the effective current range based on the average SOH of the fuel cell stack for each current section, and determines whether the fuel cell stack has failed based on the overall average SOH.

System, methods, and other embodiments described herein relate to safely activating a fuel cell (FC) within a generator. In one embodiment, a method includes initiating a test for sensitive systems of a generator using backup power including a battery. The method also includes powering an FC and a direct current (DC) converter within the generator to an operational level using the battery, wherein the DC converter stabilizes a circuit fed by the FC. The method also includes, upon successfully completing the test and powering the FC and the DC converter, energizing a load inverter after completing a non-critical sequence that controls support systems of the generator, wherein the DC converter stabilizes energy between the FC, the battery, and the load inverter.