Abstract: A fuel cell system includes: a fuel cell stack; an oxygen tank; an oxygen pipe connecting the fuel cell stack and the oxygen tank; an oxygen regulator disposed in the oxygen pipe and configured to regulate a flow rate of oxygen to be supplied from the oxygen tank to a cathode of the fuel cell stack; an oxygen stop valve disposed in the oxygen pipe; and a controller configured to execute, when activating or stopping the fuel cell stack: a first process of opening the oxygen stop valve and the oxygen regulator; a second process of closing the oxygen stop valve and the oxygen regulator when a cathode internal pressure reaches a predetermined first cathode pressure; and a third process of outputting a signal indicating occurrence of oxygen leakage when the cathode internal pressure after a predetermined period is lower than a predetermined second cathode pressure.

Abstract: A fuel cell system includes: a fuel cell stack; a fuel tank; a fuel pipe connecting the fuel cell stack and the fuel tank; a fuel regulator disposed in the fuel pipe and configured to regulate a flow rate of fuel gas to be supplied from the fuel tank to an anode; a fuel stop valve disposed in the fuel pipe; and a controller. The controller is configured to execute, when activating or stopping the fuel cell stack: a first process of opening the fuel stop valve and the fuel regulator; a second process of closing the fuel stop valve and the fuel regulator when an anode internal pressure reaches a predetermined first anode pressure; and a third process of outputting a signal indicating occurrence of fuel leakage when the anode internal pressure after a predetermined first period is lower than a predetermined second anode pressure.

Abstract: A voltage control system includes: a converter controlling portion; a current value acquisition portion; and a voltage value acquisition portion. The converter controlling portion sets a duty ratio in a present cycle by adding an addition term to a feedforward term, the addition term being determined by use of a current deviation, which is a difference between a target value of an output current in the present cycle and a current measured value in a previous cycle, and the duty ratio in the previous cycle, the addition term being corresponding to an increase of the output current in the present cycle.

Abstract: A fuel cell vehicle according to the present disclosure includes: a fuel cell; a multiphase converter configured to control an output current of the fuel cell; a current sensor provided in each phase of the multiphase converter; an electric load configured to receive power supplied from the fuel cell; and a control unit. The control unit performs, when it detects an excess or a deficiency of electric energy of the electric load, replacement of phases driven by the multiphase converter while the output current of the fuel cell is kept constant, and determines, when the excess or the deficiency of the electric energy of the electric load is eliminated after the replacement of the phases, that an offset failure has occurred in the current sensor provided in the phase that has been driven before the replacement.

Abstract: A fuel cell system includes: a fuel cell; a reaction gas supplier which supplies a fuel gas and an oxidizing gas to the fuel cell; a first converter which converts the output voltage of the fuel cell; a secondary battery; a connection line connecting the first converter and the secondary battery in parallel to a load; and a controller. The controller includes a first operation mode and a second operation mode. In the first operation mode, the first converter is operated with a step-up capability that is able to be realized by the first converter. In the second operation mode, the first converter is operated with the maximum step-up capability that is able to be realized by the first converter and in which the reaction gas supplier is used to control the output current of the fuel cell.

Abstract: The present invention provides a technique capable of satisfying both the restoration of an output voltage of a fuel cell and an improvement of electric power responsiveness in a fuel cell system in a situation in which its operation status is restored to a normal operation from an operation having low power generation efficiency. A controller updates a lower limit voltage threshold in accordance with the restoration of an FC voltage until the operation status is restored to a normal operation from an operation having low power generation efficiency, such as an intermittent operation and a warmup operation (step S1). The controller increases an FC current in accordance with the updated lower limit voltage threshold (steps S2 and S3) to thereby satisfy both the requirements of the restoration of the output voltage of the fuel cell stack and the improvement of the electric power responsiveness.

Abstract: A voltage control system includes a converter device, and a controller configured to set a duty ratio according to a current target value so as to cause the converter device to repeatedly perform a boost operation according to the duty ratio. The controller is configured to set the duty ratio by use of a basic term including a feedforward term, and an additional term, the feedforward term being derived by use of a measured value of a magnitude of an input of a reactor provided in the converter device and a measured value of a magnitude of an output of the reactor or by use of respective target values of the magnitude of the input and the magnitude of the output in the reactor, the additional term being derived by use of the variation of the current target value during one cycle.

Abstract: A fuel cell vehicle according to the present disclosure includes: a fuel cell; a multiphase converter configured to control an output current of the fuel cell; a current sensor provided in each phase of the multiphase converter; an electric load configured to receive power supplied from the fuel cell; and a control unit. The control unit performs, when it detects an excess or a deficiency of electric energy of the electric load, replacement of phases driven by the multiphase converter while the output current of the fuel cell is kept constant, and determines, when the excess or the deficiency of the electric energy of the electric load is eliminated after the replacement of the phases, that an offset failure has occurred in the current sensor provided in the phase that has been driven before the replacement.

Abstract: A fuel cell system includes a control section that: transmits a first current command value used to lower an output voltage of a fuel cell stack to a fuel cell converter when the output voltage becomes equal to or higher than a first voltage; transmits a second current command value used to boost the output voltage to the fuel cell converter when the output voltage becomes equal to or lower than a second voltage; stores the first current command value as a first storage value when the output voltage becomes equal to or lower than the second voltage; stores the second current command value as a second storage value when the output voltage becomes equal to or higher than the first voltage; and transmits a current command value that falls between the first storage value and the second storage value to the fuel cell converter.

Abstract: A current control system includes a boost converter, and a converter controller that selectively performs control in a continuous mode using a calculated duty ratio for the continuous mode and control in a discontinuous mode using a calculated duty ratio for the discontinuous mode. The converter controller performs, at least in calculation of the duty ratio for the continuous mode, rising speed adjustment processing for adjusting a parameter used for the calculation of the duty ratio so that a rising amount of the duty ratio is restricted relative to the duty ratio used in a last cycle in accordance with a predetermined limit value, so as to restrict a rising speed of the duty ratio for the continuous mode more than a rising speed of the duty ratio for the discontinuous mode.

Abstract: A fuel cell system including: a fuel cell; a voltage sensor that measures output voltage of the fuel cell; a converter that boosts the output voltage; and a control unit that controls the converter using a duty ratio including a feedforward term and a feedback term, the feedforward term being set to perform feedforward control, the feedback term being set to perform feedback control, wherein when the control unit causes the converter to boost the output voltage, and when the feedforward term calculated by specified Expression I exceeds an upper limit calculated by specified Expression II, the control unit causes the converter to boost the voltage output from the fuel cell with the duty ratio including the upper limit and the feedback term.

Abstract: The present disclosure is made in order to reduce inaccuracy of current sensors. A fuel cell system includes a converter configured to convert output voltage of the fuel cell, and a current sensor including a preliminarily magnetized magnetic core and configured to measure current flowing in the converter from the fuel cell. A controller operates in a first driving mode in which a maximum current value in a target circuit of current measurement by the current sensor is lower than a current value for preliminary magnetization of the magnetic core, and a second driving mode in which the maximum current value in the target circuit is higher than the maximum current value in the target circuit in the first driving mode. When an accumulated temperature value of the current sensor in the first driving mode exceeds a threshold, the second driving mode is executed, followed by the first driving mode.

Abstract: The present disclosure is made in order to reduce inaccuracy of current sensors. A fuel cell system 100 comprises a converter 150 configured to convert output voltage of the fuel cell 1, and a current sensor CS1 including a preliminarily magnetized magnetic core MC1 and configured to measure current flowing in the converter 150 from the fuel cell 1. A controller 160 comprises, as driving modes of the fuel cell system 100, a first driving mode DM1 in which a maximum current value IL1max in a target circuit of current measurement by the current sensor CS1 is lower than a current value for preliminary magnetization of the magnetic core and a second driving mode DM2 in which the maximum current value IL2max in the target circuit is higher than the maximum current value IL1max in the target circuit in the first driving mode DM1.

Abstract: A fuel cell system in which power generation is performed by a fuel cell, comprising: a power generation controller that performs: first control in which at least one of power control for preventing generated power from exceeding an upper limit value, voltage control for preventing generated voltage from falling below a lower limit value and current control for preventing generated current from exceeding an upper limit value is performed and second control in which the generated voltage is prevented from exceeding an upper limit value; and a priority instructor that instructs the power generation controller to prioritize the first control over the second control when the first control and the second control collide with each other.

Abstract: A fuel cell system includes a control section that: transmits a first current command value used to lower an output voltage of a fuel cell stack to a fuel cell converter when the output voltage becomes equal to or higher than a first voltage; transmits a second current command value used to boost the output voltage to the fuel cell converter when the output voltage becomes equal to or lower than a second voltage; stores the first current command value as a first storage value when the output voltage becomes equal to or lower than the second voltage; stores the second current command value as a second storage value when the output voltage becomes equal to or higher than the first voltage; and transmits a current command value that falls between the first storage value and the second storage value to the fuel cell converter.

Abstract: The present invention enables the determination of an operating point of a fuel cell so as to prioritize the fulfillment of an amount of required power generation while avoiding various limitations, such as a current limit, in a fuel cell system that warms up the fuel cell by a low efficiency operation. A controller 70 multiplies a voltage command value Vcom obtained in step S3 by a current command value Icom obtained in step S1, then, this is divided by a final voltage command value Vfcom obtained in step S4, thereby obtaining a final current command value Ifcom to determine an operating point (Ifcom, Vfcom) during a warm-up operation (step S5), and then the process ends.

Abstract: A fuel cell system comprising: a power generation controller that controls a value subject to control, which is a value exhibiting a power generating state by a fuel cell and is a value that is affected by alternating current applied to the fuel cell, to approach a target value; a dead zone setter that sets a dead zone with the target value as a reference; and, a stopper that stops the control by the power generation controller when the value subject to control is contained in the dead zone.

Abstract: There is provided a fuel cell system. This fuel cell system comprises a fuel cell configured to generate electric power using reactive gases; a voltage sensor configured to measure a voltage output from the fuel cell; a converter configured to boost an input voltage that is input from the fuel cell; and a controller configured to control the converter. In the case where the voltage output from the fuel cell to the converter is to be boosted after a changeover of an operating state of the fuel cell system from an intermittent operation to an ordinary operation, when a duty ratio D1 calculated by Mathematical Formula I is greater than a duty ratio D2 calculated by Mathematical Formula II, the controller causes the converter to boost the voltage output from the fuel cell at the duty ratio D2. [ Math .

Abstract: A fuel cell system includes: a fuel cell outputting a current; a supply unit supplying oxidant gas; a flow-amount measurement unit measuring a flow amount of the oxidant gas; and a controller that feed-back controls the supply unit such that a measured flow-amount value converges toward a target flow-amount value, wherein the controller determines an acceptable current value in accordance with the measured flow-amount value, restricts the current to the acceptable current value or less, controls the current in accordance with a requested current value of the fuel cell; and performs a changing-suppression processing, when a condition continues for a predetermined period, the condition including that a changing width of the requested current value is equal to or less than a first value and a difference between the requested current value and the acceptable current value is equal to or less than a second value.

Abstract: A fuel cell system mounted in a vehicle includes a fuel cell supplying electric power to a motor driving the vehicle, a pump supplying oxygen to the fuel cell, an accelerator position detection unit detecting an accelerator depression amount of the vehicle, and a control unit calculating electric power required to be generated by the fuel cell and electric power required for driving of the pump based on the accelerator depression amount and controlling the pump based on the electric power required for the driving, in which the control unit calculates the electric power required for the driving such that a rate of increase in the electric power required for the driving exceeds a rate of increase in the electric power required to be generated when the calculated electric power required to be generated increases.