Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

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 power supply includes fuel cell, secondary battery, power converter, current detecting unit and control unit. The power converter couples the fuel cell with the secondary battery, and is adapted to convert current outputted by the fuel cell into output current. The current detecting unit couples the power converter with the secondary battery and adapted to detect charging current of the output current transferred to the secondary battery. The control unit couples the current detecting unit with the power converter and is adapted to: when the charging current is greater than a charging current upper-limit-setting value of the secondary battery, a down-adjustment signal is outputted to the power converter to reduce the output current; and when the charging current is less than the charging current upper-limit-setting value, an up-adjustment signal is outputted to the power converter to increase the output current.

System, methods, and other embodiments described herein relate to safely ceasing fuel cell (FC) operation and idling components of a generator. In one embodiment, a method includes ceasing power generation by reducing fuel to an FC within a generator while maintaining energy to sensitive components by a battery. The method also includes idling a direct current (DC) converter and a load inverter associated with the power generation before idling the battery. The method also includes, upon successfully completing tests and powering down non-critical components of the generator, entering the generator into a standby status.

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.

To provide a fuel-efficient fuel cell system configured to eliminate flooding in a fuel-based gas flow path, etc. The fuel cell system is a fuel cell system comprising a first fuel cell stack, a second fuel cell stack, a fuel gas supplier, a first supply flow path, a first circulation flow path, a second supply flow path, a second circulation flow path, a first bypass flow path which includes a first on-off valve, a second bypass flow path which includes a second on-off valve, a temperature detector, a current detector, a voltage detector and a controller.

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.

Disclosed is a method of controlling an air supply system for a fuel cell. The air supply system includes a fuel cell stack, an air channel to supply air to an inlet of the fuel cell stack, a gas adsorption unit disposed on the air channel and configured to adsorb oxygen contained in air introduced into the air channel. In particular, the method includes: determining whether a power generation operation of the fuel cell stack is resumed; when the power generation operation of the fuel cell stack is resumed, controlling a voltage source to apply a voltage to the gas adsorption unit; and supplying air to the fuel cell stack through the air channel in a state in which the voltage is applied to the gas adsorption unit.

The control device is configured so that when a temperature of the fuel cell at the time of start of power generation of the fuel cell is less than a standard temperature, it makes the fuel cell generate power so that the amount of heat generation of the fuel cell accompanying the power generation loss becomes a first amount of heat generation and so that when a cumulative value of current of a time period during which the fuel cell is made to generate power so that the amount of heat generation becomes the first amount of heat generation is equal to or greater than a predetermined cumulative value, it makes the fuel cell generate power so that the amount of heat generation becomes a second amount of heat generation larger than the first amount of heat generation.