A fuel-cell system for powering an electrical load, the system having first and second fuel cells, each having a positive node and a negative node. The positive node of the second fuel cell is electrically coupled to the negative node of the first fuel cell, and the positive node of the first fuel cell and the negative node of the second fuel cell are electrically coupled to the electrical load. Each fuel cell is electrically coupled to the electrical load without a power converter.

A vehicle includes a fuel cell, an inlet valve, a purge valve, and a controller. The fuel cell has an anode side configured to receive hydrogen. The inlet valve is configured to open to deliver the hydrogen to the anode side. The purge valve is configured to open to purge water and nitrogen from the anode side. The controller is programmed to, operate the inlet valve to inject hydrogen into the anode side via opening the inlet valve followed by closing the inlet valve. The controller is further programmed to, in response to a concentration of the hydrogen in the anode side being less than threshold, open the purge valve to purge water and nitrogen from the anode side.

A fuel cell stack includes a plurality of fuel cells arranged in the direction of the stack and tensioned by means of tension elements, of which at least one has a cell voltage tap for electrical connection to a cell monitoring unit, wherein the at least one cell voltage tap is mechanically secured by at least one of the tension elements as regards the connection to the fuel cells. A fuel cell device and a motor vehicle with a fuel cell device are also provided.

An online impedance spectrum measuring device and method for a vehicle-mounted hydrogen fuel cell includes: a controllable alternating current source, configured to apply a sinusoidal alternating signal; a cell voltage signal preceding-stage measuring circuit, configured to select to communicate with one monocell via a voltage signal gating circuit; a current sensor and a cell current signal preceding-stage measuring circuit connected with the current sensor; and a signal conditioning and amplifying circuit, a multi-channel simultaneous sampling analog-digital conversion circuit, a digital signal processor and an upper computer, which are connected in sequence, wherein the signal conditioning and amplifying circuit is connected to the cell voltage signal preceding-stage measuring circuit and the cell current signal preceding-stage measuring circuit, separately; and the upper computer is connected with the controllable alternating source and the voltage signal gating circuit.

Presented are intelligent fuel cell systems (FCS) with logic for evacuating water from anode headers of a fuel cell stack, methods for making/using such systems, and vehicles equipped with such systems. A method of operating an FCS includes a system controller confirming the FCS is running and, once confirmed, receiving a bleed request to remove exhaust gas from exhaust output by the anode. Responsive to the bleed request, the controller determines a total bleed valve use (TBVU) indicating prior bleed requests completed by an anode bleed valve, and thereafter determines if the TBVU is less than a maximum bleed valve use (MBVU). If so, the controller responsively commands the bleed valve to bleed the exhaust gas from the anode exhaust. If TBVU is not less than MBVU, the controller commands a header drain valve to bleed the exhaust gas from the anode exhaust and drain water from the anode header.

An apparatus for converting power of a fuel cell for power generation to remove an open voltage of the fuel cell and a method thereof are provided. A controller links current to a system or load to reduce an open circuit voltage (OCV) of the fuel cell before power generation of the fuel cell is started, after the fuel cell is started. A power converter converts and supplies power generated by the fuel cell to the system or load. The apparatus removes an OCV of a fuel cell stack to prevent performance and life of the fuel cell from being reduced.

An apparatus for converting power of a fuel cell for power generation to remove an open voltage of the fuel cell when a failure occurs during power generation of the fuel cell and a method thereof are provided. A power converter converts and supplies power generated by the fuel cell to a system or load. A controller detects a failure occurring in the fuel cell, the power converter, or the system or load, while the fuel cell is driven, and reduces an open circuit voltage (OCV) of the fuel cell by a dummy resistor connected with an output terminal of the fuel cell, when the failure occurs in the fuel cell, the power converter, or the system or load. The apparatus removes an OCV of a fuel cell stack to prevent performance and life of the fuel cell from being reduced.

Methods and systems may provide for technology to predict a future increase in power demand on a fuel cell based on route data associated with a vehicle powered by the fuel cell and reduce an operating temperature of the fuel cell prior to the future increase in power demand. The technology may also provide supplemental power from a battery to the vehicle while the operating temperature of the fuel cell is being reduced.

A method for reducing cell degradation in a fuel cell system includes adding oxygen-containing gas to a fuel in the anode chamber to prevent an increase in a cell voltage above a predetermined maximum value.

A fuel cell system includes a fuel cell in which cells are stacked, a voltage sensor that detects a voltage in unit of one or more of the cells, a control unit that determines an operating point of the fuel cell and causes the fuel cell to operate. The control unit causes the fuel cell to operate at a low efficiency operating point having a lower efficiency than an efficiency of a reference operating point in a warm-up operation. In the warm-up operation, the control unit calculates a total number of the cells in which the voltage detected by the voltage sensor is equal to or less than a predetermined first reference voltage and calculates an exhaust hydrogen concentration based on the total number or the cells.