The invention relates to a starting method for a fuel cell system (100), particularly for an air/air start of the fuel cell system (100). The method enables the reduction of damaging half-cell voltages in the fuel cell stack (10) through voltage limitation by means of a DC voltage converter. The homogeneous flushing of the fuel cell stack (10) required for this takes place by means of introduction of an anode operating medium into an anode inlet channel (17) of the otherwise sealed fuel cell stack (10) until a predetermined pressure is reached and flushing of the active areas of the fuel cells (11) of the stack (10) after said pressure is reached through opening of an anode discharge adjusting aid (26), preferably arranged in an exhaust coupling (29) connecting the anode exhaust line (22) and the cathode exhaust line (31). In preferred embodiments of the method according to the invention, a provision is to improve the mass flow of the anode operating medium in an anode supply (20) of the fuel cell stack (10) through suitable operation of a recirculation conveying mechanism (27). Another subject matter of the invention is also a fuel cell system (100) with a control unit (70) for implementing the method according to the invention.

A method for calculating voltage loss of a fuel cell is provided. The method includes sensing an open circuit voltage that is generated in a stack when the switch is opened and detecting an operation voltage and an operation current that are generated in the stack when the switch is closed. A first change graph of voltage data over time is calculated using the voltage data and current data from a time when the switch is opened in a state where the switch is closed. A first voltage of a point at which a trend line for an interval where the voltage data linearly varies with the time meets the first change graph is sensed and then an ohmic resistance voltage loss is calculated using a difference between the first voltage and the operation voltage.

A method of shutting down a fuel cell system includes a fuel cell includes generating power via an electrochemical reaction between a fuel gas and an oxidant gas. A shutdown command is output to the fuel cell to stop generating power. The fuel cell is controlled to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell. At least one of voltage, current, and power output from the fuel cell is detected during the oxygen consumption process. Whether an abnormality occurs during the oxygen consumption process is determined based on at least one of the voltage, the current, and the power. The fuel cell is controlled to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

Disclosed is a power control system and method of a fuel cell including a fuel cell that generates electricity; a load device that is electrically connected to the fuel cell; a DC/DC converter that is disposed between the fuel cell and the load device, and converts power between a low side of the DC/DC converter electrically connected to the fuel cell and a high side of the DC/DC converter electrically connected to the load device; a battery that is electrically connected to the high side of the DC/DC converter in parallel with the load device; and a controller that monitors a voltage of the high side of the DC/DC converter or a voltage of the low side of the DC/DC converter, and controls output power of the fuel cell or power consumption of the load device based on the monitored voltage of the high side or the monitored voltage of the low side.

The present disclosure generally relates to systems and methods for purging water or gas from a fuel cell system. The fuel cell system may include a multi-phase valve system and/or a separate valve system. The opening and closing of the valve systems for removing gas and water is controlled by a controller,

The present disclosure relates to an apparatus for controlling an operation of a fuel cell system and a method therefor. The present disclosure may include a voltage sensor that measures an output voltage of a fuel cell stack, an air compressor that supplies air to a cathode of the fuel cell stack, a valve driver that adjusts an opening degree of an Airflow Control Valve (ACV), and a controller that, in an idle stop state, drives the air compressor at a lowest level and controls the opening degree of the ACV such that the output voltage of the fuel cell stack maintains a reference range.

A system and method for controlling power for a fuel cell are disclosed. The system includes: a fuel cell; a load device electrically connected to the fuel cell; a stack controller configured to set a stack limit current on the basis of a current output current of the fuel cell, the stack limit current configured to limit an output current of the fuel cell on the basis of an output voltage of the fuel cell; and a load controller configured to set a consumption limit current on the basis of the set stack limit current, the consumption limit current configured to limit a consumption current of the load device, the load controller being configured to control the consumption current of the load device to a value equal to or lower than the set consumption limit current.

A fuel cell system includes a first fuel cell having first unit cells stacked together, a second fuel cell having second unit cells stacked together, a first voltage detector, a second voltage detector, and a controller. The first voltage detector detects voltage of the first unit cells for every “N” unit cells on average, and the second voltage detector detects voltage of the whole second fuel cell, or detects voltage of the second unit cells for every “M” unit cells on average. The controller determines whether any of the first unit cells is in a fuel deficiency state, by referring to a detection result of the first voltage detector, and performs a cancellation process to cancel the fuel deficiency state, on the first fuel cell that is in a power generating state, while stopping power generation of the second fuel cell, when an affirmative decision is obtained.

Systems and methods for improving conditions for anion contaminant removal in a cathode of a PEMFC system are presented. A fuel cell system consistent with certain embodiments may include a cathode compartment having a compressor coupled thereto. The compressor may be configured to receive an input cathode gas via a compressor input and supply the input cathode gas to the cathode compartment via a compressor output. The fuel cell system may further include a cathode gas recirculation value coupled to the cathode compartment configured to receive a cathode exhaust gas output and to selectively provide at least a portion of the cathode exhaust gas output to the compressor input. Consistent with certain embodiments disclosed herein, the compressor may be further configured to supply at least a portion of the cathode exhaust gas output to the cathode compartment via the compressor output.

A fuel cell system includes a fuel cell stack configured to supply power to an electric motor for driving a vehicle as well as generating power by an electrochemical reaction between a fuel gas and an oxidant gas, a discharge circuit and the discharge control circuit. The discharge circuit may form a plurality of discharge paths through which power generated in the fuel cell stack is discharged switching elements switching the connection relationships between resistance elements. The discharge control circuit form a second discharge path whose resistance value is smaller than the resistance value of the first discharge path and to switch the discharge through a first discharge path to discharge through the second discharge path when the detected voltage that is detected by the voltage detection unit is lower than a predetermined threshold voltage during the discharge through the first discharge path.