In a method of inspecting output of a fuel cell, a reduction step is performed, and thereafter, a measurement step is performed. In the reduction step, reduction treatment is applied to electrode catalyst contained in an anode and a cathode. After the reduction treatment is applied to the electrode catalyst of the anode and the cathode, in the measurement step, measurement current which is smaller than rated current of the fuel cell, is applied to the anode and the cathode to inspect the output of the fuel cell.

A controller-executed method for conditioning a membrane electrode assembly (MEA) in a fuel cell for use in a fuel cell stack includes humidifying a fuel inlet to the stack to a threshold relative humidity level, and maintaining a current density and cell voltage of the fuel cell at a calibrated current density level and hold voltage level, respectively, via the controller in at least one voltage recovery stage. The recovery stage has a predetermined voltage recovery duration. The method includes measuring the cell voltage after completing the predetermined voltage recovery duration, and executing a control action with respect to the fuel cell or fuel cell stack responsive to the measured cell voltage exceeding a target voltage, including recording a diagnostic code via the controller indicative of successful conditioning of the MEA. A fuel cell system includes the fuel cell stack and controller.

A fuel cell system includes a first plurality of fuel cells having a cathode and an anode. The plurality of fuel cells is configured to produce electrical power having a current and a voltage output. The plurality of fuel cells includes a first conductive plate and a second conductive plate. A shunt is electrically connected to the first conductive plate and the second conductive plate for shunting voltage output between the cathode and the anode. The shunt is mounted to, and supported by, the plurality of fuel cells. The shunt is connected to a control mechanism to control a shorting of one or more fuel cells of the plurality of fuel cells. The control mechanism is mounted to, and supported by, the plurality of fuel cells.

In a method of inspecting an output of a fuel cell, an oxidation step is performed, and thereafter, a measurement step is performed. In the oxidation step, oxidation treatment is applied to an electrode catalyst contained in an anode and a cathode. After the oxidation treatment is applied to the electrode catalyst of the anode and the cathode, in the measurement step, a measurement current which is smaller than a rated current of the fuel cell is applied to the anode and the cathode to measure the output of the fuel cell.

A fuel cell device is improved for operating conditions during a partial load operation. The fuel cell device comprises a cell stack formed by electrically connecting fuel cells for generating power by fuel gas and oxygen-containing gas; a fuel gas supply unit for supplying the fuel gas to the fuel cells; and a power adjustment unit for adjusting the amount of current that is supplied to an external load and a controller for controlling the fuel gas supply unit and the power adjustment unit. The controller adjusts, during the partial load operation of the fuel cell device and when the fuel gas supplied to the cell stack is at a low flow rate. The relationship between a fuel utilization rate of the cell stack and the amount of power generated by the cell stack can be nonlinear.

When electric power requested from a load exceeds a predetermined reference value, an operating state of the fuel cell system is controlled so as to enable a normal operation mode where the fuel cell generates electric power corresponding to the requested electric power. When the requested electric power is the reference value or less, the operating state is controlled to enable an intermittent operation mode. A refresh process for sweeping current from the fuel cell and lowering the voltage of the fuel cell to a reduction voltage is executed during a shift from the intermittent operation mode to the normal operation mode. The current swept from the fuel cell at the start of the refresh process is reduced more as an oxygen amount in the fuel cell at the end of the intermittent operation mode is smaller.

A method for power control of a fuel cell system in a vehicle is disclosed. The requested fuel cell system power by the vehicle is converted into a power request made of the fuel cell by an expected power of auxiliary drives of the fuel cell system at the requested fuel cell system power being added to the requested fuel cell system power. A media supply of the fuel cell which corresponds to the power request made of the fuel cell is requested. The electrical loading of the fuel cell with current is performed in accordance with a model of the cathode dynamics such that a control variable of the control operation is matched to the media dynamics, and the power release is performed such that the fuel cell is loaded only when the adequate media supply is ensured.

Disclosed is a control system for a fuel cell system that includes at least two or more fuel cell groups which each have at least one fuel cell connected in parallel. The fuel cell control system comprises: a unit level controller configured to control an output of an individual fuel cell; a group level controller configured to determine the output distribution of the individual fuel cells within the fuel cell group based on the performance decrease rates of the individual fuel cells within the fuel cell group; and a system level controller configured to determine the total output of the fuel cell system according to the power demand for the grid and determine the output distribution for each of the fuel cell groups in correspondence to the total output.

Methods are disclosed for starting up a fuel cell system from starting temperatures below 0 C. The methods apply to systems comprising a solid polymer electrolyte fuel cell stack whose cathodes comprise an oxygen reduction reaction (ORR) catalyst and whose anodes comprise both a hydrogen oxidation reaction (HOR) catalyst and an oxidation evolution reaction (OER) catalyst. In the methods, from the beginning of starting up until the fuel cell temperature reaches 0 C., the fuel cell stack current is kept sufficiently low such that the current density drawn does not exceed the stack's capability for the oxidation evolution and the oxygen reduction reactions to occur at the anode and cathode respectively (i.e. current density drawn is less than the stack's maximum OER/ORR current density).

In an electric potential difference forming step of a method of inspecting output of a fuel cell, a hydrogen gas as an anode gas is supplied to an anode, and an inert gas as a cathode gas is supplied to the cathode to generate an electric potential difference between the anode and the cathode. In a maintaining step, measurement current which is smaller than rated current of the fuel cell is applied to the anode and the cathode, and the voltage between the anode and the cathode is maintained at less than the reduction potential of the electrode catalyst. In a measurement step, in the state where the measurement current is applied to the anode and the cathode, and voltage between the anode and the cathode is maintained, the cathode gas is changed to a mixed gas, and then, output of the fuel cell is measured.