A fuel cell device is provided, including a media system for supplying fluid media to electrochemical units of the fuel cell device and/or for discharging fluid media from the electrochemical units of the fuel cell device, wherein the media system includes at least one valve to which, in a standard operating state of the fuel cell device, an electrical standard input power is suppliable in order to maintain the valve in a desired valve state. The fuel cell device is able to be reliably started with as little effort as possible, even under frost conditions. The fuel cell device is switchable into a heating operating state in which an electrical heating input power that is greater than the electrical standard input power is suppliable to the at least one valve.

A fuel cell system FCS includes a fuel cell 10, a high voltage circuit 21 for driving an electromotor 42, and a relay 41 for electrically connecting or blocking the fuel cell 10 to or from the high voltage circuit 21. A control unit 50 obtains insulation decrease information in accordance with a request for starting the fuel cell, and performs, when a specified insulation decrease occurred region is not a fuel cell region SE1 including the fuel cell and the cooling circuit, conductivity reduction process on cooling liquid using a conductivity reduction unit 113 before having a relay 41 connect, and has the relay 41 connect after completing the conductivity reduction process.

A fuel cell system FCS includes a fuel cell 10, a high voltage circuit 21 for driving an electromotor 42, and a relay 41 for electrically connecting or blocking the fuel cell 10 to or from the high voltage circuit 21. A control unit 50 obtains insulation decrease information in accordance with a request for starting the fuel cell, and performs, when a specified insulation decrease occurred region is not a fuel cell region SE1 including the fuel cell and the cooling circuit, conductivity reduction process on cooling liquid using a conductivity reduction unit 113 before having a relay 41 connect, and has the relay 41 connect after completing the conductivity reduction process.

A fuel cell power plant includes an energy storage system connected in parallel with a fuel cell system. The fuel cell system includes a controller, a fuel flow system, an air flow system, and an internal water management system. The controller is operable to receive, as inputs, the energy storage system state of charge and the power demand from an electric load. The controller is further operable to determine a power split set point and execute commands, as output, to control operation of the air flow system, wherein the air flow system actively regulates the proportion of current flow between the fuel cell system and the energy storage system to meet the power demand of the electric load.

A device for detecting a current leakage and a current leakage detection system including the same are provided. The device for detecting a current leakage includes a magnetic core having an internal space and both ends the core are separated from each other. An electric wiring extends to pass through the internal space of the magnetic core, and is connected between a power source and an electric load to supply power from the power source to the electric load. A hall sensor senses a magnetic field induced in the magnetic core.

A fuel cell system includes a plurality of electrical components that are supplied with electric power generated by a fuel cell, a refrigerant circuit that cools the fuel cell using a refrigerant, a tank that is connected to the refrigerant circuit, stores the refrigerant, and is replenished with the refrigerant, a detecting unit that detects an insulation resistance value of the fuel cell system, and an identification unit that identifies at what position of the fuel cell system the insulation resistance value has decreased when it is detected that the insulation resistance value has decreased. The detecting unit performs a process of determining whether the decrease in insulation resistance value is temporary when the identified position is the fuel cell and determines that there is no failure requiring repair when the decrease in insulation resistance value is temporary.

A fuel cell system FCS includes a fuel cell 10, a high voltage circuit 21 for driving an electromotor 42, and a relay 41 for electrically connecting or blocking the fuel cell 10 to or from the high voltage circuit 21. A control unit 50 obtains insulation decrease information in accordance with a request for starting the fuel cell, and performs, when a specified insulation decrease occurred region is not a fuel cell region SE1 including the fuel cell and the cooling circuit, conductivity reduction process on cooling liquid using a conductivity reduction unit 113 before having a relay 41 connect, and has the relay 41 connect after completing the conductivity reduction process.

A method for addressing electrical grid frequency changes by a fuel cell system includes measuring, by a frequency sensor, a frequency of an electrical grid, determining that the frequency of the electrical grid differs from a normal frequency of the electrical grid by a threshold, determining, based at least in part on the measured frequency, an AC power setpoint bias, applying a magnitude limit, a rate-of-change limit, and a duration limit to the determined AC power setpoint bias to generate a limited power setpoint bias, generating a frequency adjusted power setpoint based on the limited power setpoint bias, and providing the frequency adjusted power setpoint to one or more control modules of the fuel cell system such that the fuel cell system adjusts a power output based on a difference between the measured frequency and the normal frequency.

A method of controlling purge of a fuel cell system for a vehicle is provided. The method determines whether a purge function is normally performed in controlling purge of discharging nitrogen, hydrogen, and vapor within an anode of a fuel cell system. Particularly, the method confirms whether purge is performed by measuring a duty or a current applied to a hydrogen supply valve and measuring a change in the duty before and after an application of a purge valve operation command while adjusting a pressure inside the anode, which supplies hydrogen, to be uniform. Further, a hydrogen supply amount supplied into an anode is estimated and a change rate of a hydrogen supply amount supplied to the anode and a hydrogen amount consumed during a generation of the fuel cell system are estimated during a purge function, to determine whether purge is actually performed based on the estimated information.

The disclosed embodiments relate to the design of a portable and cost-effective fuel cell system for a portable computing device. This fuel cell system includes a fuel cell stack which converts fuel into electrical power. It also includes a fuel source for the fuel cell stack and a controller which controls operation of the fuel cell system. The fuel system also includes an interface to the portable computing device, wherein the interface comprises a power link that provides power to the portable computing device, and a bidirectional communication link that provides bidirectional communication between the portable computing device and the controller for the fuel cell system.